Message ID | 20210913140229.24797-1-omosnace@redhat.com |
---|---|
State | New |
Headers | show |
Series | [v4] lockdown,selinux: fix wrong subject in some SELinux lockdown checks | expand |
On Mon, Sep 13, 2021 at 4:04 PM Ondrej Mosnacek <omosnace@redhat.com> wrote: > > Commit 59438b46471a ("security,lockdown,selinux: implement SELinux > lockdown") added an implementation of the locked_down LSM hook to > SELinux, with the aim to restrict which domains are allowed to perform > operations that would breach lockdown. > > However, in several places the security_locked_down() hook is called in > situations where the current task isn't doing any action that would > directly breach lockdown, leading to SELinux checks that are basically > bogus. > > To fix this, add an explicit struct cred pointer argument to > security_lockdown() and define NULL as a special value to pass instead > of current_cred() in such situations. LSMs that take the subject > credentials into account can then fall back to some default or ignore > such calls altogether. In the SELinux lockdown hook implementation, use > SECINITSID_KERNEL in case the cred argument is NULL. > > Most of the callers are updated to pass current_cred() as the cred > pointer, thus maintaining the same behavior. The following callers are > modified to pass NULL as the cred pointer instead: > 1. arch/powerpc/xmon/xmon.c > Seems to be some interactive debugging facility. It appears that > the lockdown hook is called from interrupt context here, so it > should be more appropriate to request a global lockdown decision. > 2. fs/tracefs/inode.c:tracefs_create_file() > Here the call is used to prevent creating new tracefs entries when > the kernel is locked down. Assumes that locking down is one-way - > i.e. if the hook returns non-zero once, it will never return zero > again, thus no point in creating these files. Also, the hook is > often called by a module's init function when it is loaded by > userspace, where it doesn't make much sense to do a check against > the current task's creds, since the task itself doesn't actually > use the tracing functionality (i.e. doesn't breach lockdown), just > indirectly makes some new tracepoints available to whoever is > authorized to use them. > 3. net/xfrm/xfrm_user.c:copy_to_user_*() > Here a cryptographic secret is redacted based on the value returned > from the hook. There are two possible actions that may lead here: > a) A netlink message XFRM_MSG_GETSA with NLM_F_DUMP set - here the > task context is relevant, since the dumped data is sent back to > the current task. > b) When adding/deleting/updating an SA via XFRM_MSG_xxxSA, the > dumped SA is broadcasted to tasks subscribed to XFRM events - > here the current task context is not relevant as it doesn't > represent the tasks that could potentially see the secret. > It doesn't seem worth it to try to keep using the current task's > context in the a) case, since the eventual data leak can be > circumvented anyway via b), plus there is no way for the task to > indicate that it doesn't care about the actual key value, so the > check could generate a lot of "false alert" denials with SELinux. > Thus, let's pass NULL instead of current_cred() here faute de > mieux. > > Improvements-suggested-by: Casey Schaufler <casey@schaufler-ca.com> > Improvements-suggested-by: Paul Moore <paul@paul-moore.com> > Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") > Acked-by: Dan Williams <dan.j.williams@intel.com> [cxl] > Acked-by: Steffen Klassert <steffen.klassert@secunet.com> [xfrm] > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> for the ACPI and hibernation changes. > --- > > v4: > - rebase on top of TODO > - fix rebase conflicts: > * drivers/cxl/pci.c > - trivial: the lockdown reason was corrected in mainline > * kernel/bpf/helpers.c, kernel/trace/bpf_trace.c > - trivial: LOCKDOWN_BPF_READ was renamed to LOCKDOWN_BPF_READ_KERNEL > in mainline > * kernel/power/hibernate.c > - trivial: !secretmem_active() was added to the condition in > hibernation_available() > - cover new security_locked_down() call in kernel/bpf/helpers.c > (LOCKDOWN_BPF_WRITE_USER in BPF_FUNC_probe_write_user case) > > v3: https://lore.kernel.org/lkml/20210616085118.1141101-1-omosnace@redhat.com/ > - add the cred argument to security_locked_down() and adapt all callers > - keep using current_cred() in BPF, as the hook calls have been shifted > to program load time (commit ff40e51043af ("bpf, lockdown, audit: Fix > buggy SELinux lockdown permission checks")) > - in SELinux, don't ignore hook calls where cred == NULL, but use > SECINITSID_KERNEL as the subject instead > - update explanations in the commit message > > v2: https://lore.kernel.org/lkml/20210517092006.803332-1-omosnace@redhat.com/ > - change to a single hook based on suggestions by Casey Schaufler > > v1: https://lore.kernel.org/lkml/20210507114048.138933-1-omosnace@redhat.com/ > > arch/powerpc/xmon/xmon.c | 4 ++-- > arch/x86/kernel/ioport.c | 4 ++-- > arch/x86/kernel/msr.c | 4 ++-- > arch/x86/mm/testmmiotrace.c | 2 +- > drivers/acpi/acpi_configfs.c | 2 +- > drivers/acpi/custom_method.c | 2 +- > drivers/acpi/osl.c | 3 ++- > drivers/acpi/tables.c | 2 +- > drivers/char/mem.c | 2 +- > drivers/cxl/pci.c | 2 +- > drivers/firmware/efi/efi.c | 2 +- > drivers/firmware/efi/test/efi_test.c | 2 +- > drivers/pci/pci-sysfs.c | 6 +++--- > drivers/pci/proc.c | 6 +++--- > drivers/pci/syscall.c | 2 +- > drivers/pcmcia/cistpl.c | 2 +- > drivers/tty/serial/serial_core.c | 2 +- > fs/debugfs/file.c | 2 +- > fs/debugfs/inode.c | 2 +- > fs/proc/kcore.c | 2 +- > fs/tracefs/inode.c | 2 +- > include/linux/lsm_hook_defs.h | 2 +- > include/linux/lsm_hooks.h | 1 + > include/linux/security.h | 4 ++-- > kernel/bpf/helpers.c | 10 ++++++---- > kernel/events/core.c | 2 +- > kernel/kexec.c | 2 +- > kernel/kexec_file.c | 2 +- > kernel/module.c | 2 +- > kernel/params.c | 2 +- > kernel/power/hibernate.c | 2 +- > kernel/trace/bpf_trace.c | 25 +++++++++++++++---------- > kernel/trace/ftrace.c | 4 ++-- > kernel/trace/ring_buffer.c | 2 +- > kernel/trace/trace.c | 10 +++++----- > kernel/trace/trace_events.c | 2 +- > kernel/trace/trace_events_hist.c | 4 ++-- > kernel/trace/trace_events_synth.c | 2 +- > kernel/trace/trace_events_trigger.c | 2 +- > kernel/trace/trace_kprobe.c | 6 +++--- > kernel/trace/trace_printk.c | 2 +- > kernel/trace/trace_stack.c | 2 +- > kernel/trace/trace_stat.c | 2 +- > kernel/trace/trace_uprobe.c | 4 ++-- > net/xfrm/xfrm_user.c | 11 +++++++++-- > security/lockdown/lockdown.c | 3 ++- > security/security.c | 4 ++-- > security/selinux/hooks.c | 7 +++++-- > 48 files changed, 99 insertions(+), 79 deletions(-) > > diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c > index dd8241c009e5..47464e873749 100644 > --- a/arch/powerpc/xmon/xmon.c > +++ b/arch/powerpc/xmon/xmon.c > @@ -309,7 +309,7 @@ static bool xmon_is_locked_down(void) > static bool lockdown; > > if (!lockdown) { > - lockdown = !!security_locked_down(LOCKDOWN_XMON_RW); > + lockdown = !!security_locked_down(NULL, LOCKDOWN_XMON_RW); > if (lockdown) { > printf("xmon: Disabled due to kernel lockdown\n"); > xmon_is_ro = true; > @@ -317,7 +317,7 @@ static bool xmon_is_locked_down(void) > } > > if (!xmon_is_ro) { > - xmon_is_ro = !!security_locked_down(LOCKDOWN_XMON_WR); > + xmon_is_ro = !!security_locked_down(NULL, LOCKDOWN_XMON_WR); > if (xmon_is_ro) > printf("xmon: Read-only due to kernel lockdown\n"); > } > diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c > index e2fab3ceb09f..838ba45ecc71 100644 > --- a/arch/x86/kernel/ioport.c > +++ b/arch/x86/kernel/ioport.c > @@ -71,7 +71,7 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) > if ((from + num <= from) || (from + num > IO_BITMAP_BITS)) > return -EINVAL; > if (turn_on && (!capable(CAP_SYS_RAWIO) || > - security_locked_down(LOCKDOWN_IOPORT))) > + security_locked_down(current_cred(), LOCKDOWN_IOPORT))) > return -EPERM; > > /* > @@ -187,7 +187,7 @@ SYSCALL_DEFINE1(iopl, unsigned int, level) > /* Trying to gain more privileges? */ > if (level > old) { > if (!capable(CAP_SYS_RAWIO) || > - security_locked_down(LOCKDOWN_IOPORT)) > + security_locked_down(current_cred(), LOCKDOWN_IOPORT)) > return -EPERM; > } > > diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c > index ed8ac6bcbafb..6a687d91515b 100644 > --- a/arch/x86/kernel/msr.c > +++ b/arch/x86/kernel/msr.c > @@ -116,7 +116,7 @@ static ssize_t msr_write(struct file *file, const char __user *buf, > int err = 0; > ssize_t bytes = 0; > > - err = security_locked_down(LOCKDOWN_MSR); > + err = security_locked_down(current_cred(), LOCKDOWN_MSR); > if (err) > return err; > > @@ -179,7 +179,7 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg) > err = -EFAULT; > break; > } > - err = security_locked_down(LOCKDOWN_MSR); > + err = security_locked_down(current_cred(), LOCKDOWN_MSR); > if (err) > break; > > diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c > index bda73cb7a044..c43a13241ae8 100644 > --- a/arch/x86/mm/testmmiotrace.c > +++ b/arch/x86/mm/testmmiotrace.c > @@ -116,7 +116,7 @@ static void do_test_bulk_ioremapping(void) > static int __init init(void) > { > unsigned long size = (read_far) ? (8 << 20) : (16 << 10); > - int ret = security_locked_down(LOCKDOWN_MMIOTRACE); > + int ret = security_locked_down(current_cred(), LOCKDOWN_MMIOTRACE); > > if (ret) > return ret; > diff --git a/drivers/acpi/acpi_configfs.c b/drivers/acpi/acpi_configfs.c > index c970792b11a4..17c4e79b596e 100644 > --- a/drivers/acpi/acpi_configfs.c > +++ b/drivers/acpi/acpi_configfs.c > @@ -26,7 +26,7 @@ static ssize_t acpi_table_aml_write(struct config_item *cfg, > { > const struct acpi_table_header *header = data; > struct acpi_table *table; > - int ret = security_locked_down(LOCKDOWN_ACPI_TABLES); > + int ret = security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES); > > if (ret) > return ret; > diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c > index d39a9b474727..8cac7f683245 100644 > --- a/drivers/acpi/custom_method.c > +++ b/drivers/acpi/custom_method.c > @@ -30,7 +30,7 @@ static ssize_t cm_write(struct file *file, const char __user *user_buf, > acpi_status status; > int ret; > > - ret = security_locked_down(LOCKDOWN_ACPI_TABLES); > + ret = security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES); > if (ret) > return ret; > > diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c > index a43f1521efe6..11c462788db8 100644 > --- a/drivers/acpi/osl.c > +++ b/drivers/acpi/osl.c > @@ -198,7 +198,8 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) > * specific location (if appropriate) so it can be carried > * over further kexec()s. > */ > - if (acpi_rsdp && !security_locked_down(LOCKDOWN_ACPI_TABLES)) { > + if (acpi_rsdp && !security_locked_down(current_cred(), > + LOCKDOWN_ACPI_TABLES)) { > acpi_arch_set_root_pointer(acpi_rsdp); > return acpi_rsdp; > } > diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c > index f9383736fa0f..6569ccacd24b 100644 > --- a/drivers/acpi/tables.c > +++ b/drivers/acpi/tables.c > @@ -577,7 +577,7 @@ void __init acpi_table_upgrade(void) > if (table_nr == 0) > return; > > - if (security_locked_down(LOCKDOWN_ACPI_TABLES)) { > + if (security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES)) { > pr_notice("kernel is locked down, ignoring table override\n"); > return; > } > diff --git a/drivers/char/mem.c b/drivers/char/mem.c > index 1c596b5cdb27..330749897cd7 100644 > --- a/drivers/char/mem.c > +++ b/drivers/char/mem.c > @@ -617,7 +617,7 @@ static int open_port(struct inode *inode, struct file *filp) > if (!capable(CAP_SYS_RAWIO)) > return -EPERM; > > - rc = security_locked_down(LOCKDOWN_DEV_MEM); > + rc = security_locked_down(current_cred(), LOCKDOWN_DEV_MEM); > if (rc) > return rc; > > diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c > index 8e45aa07d662..539c91959234 100644 > --- a/drivers/cxl/pci.c > +++ b/drivers/cxl/pci.c > @@ -575,7 +575,7 @@ static bool cxl_mem_raw_command_allowed(u16 opcode) > if (!IS_ENABLED(CONFIG_CXL_MEM_RAW_COMMANDS)) > return false; > > - if (security_locked_down(LOCKDOWN_PCI_ACCESS)) > + if (security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS)) > return false; > > if (cxl_raw_allow_all) > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c > index 847f33ffc4ae..a885b4c38358 100644 > --- a/drivers/firmware/efi/efi.c > +++ b/drivers/firmware/efi/efi.c > @@ -200,7 +200,7 @@ static void generic_ops_unregister(void) > static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; > static int __init efivar_ssdt_setup(char *str) > { > - int ret = security_locked_down(LOCKDOWN_ACPI_TABLES); > + int ret = security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES); > > if (ret) > return ret; > diff --git a/drivers/firmware/efi/test/efi_test.c b/drivers/firmware/efi/test/efi_test.c > index 47d67bb0a516..942c25843665 100644 > --- a/drivers/firmware/efi/test/efi_test.c > +++ b/drivers/firmware/efi/test/efi_test.c > @@ -722,7 +722,7 @@ static long efi_test_ioctl(struct file *file, unsigned int cmd, > > static int efi_test_open(struct inode *inode, struct file *file) > { > - int ret = security_locked_down(LOCKDOWN_EFI_TEST); > + int ret = security_locked_down(current_cred(), LOCKDOWN_EFI_TEST); > > if (ret) > return ret; > diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c > index 7fb5cd17cc98..b76055dbbb03 100644 > --- a/drivers/pci/pci-sysfs.c > +++ b/drivers/pci/pci-sysfs.c > @@ -753,7 +753,7 @@ static ssize_t pci_write_config(struct file *filp, struct kobject *kobj, > u8 *data = (u8 *) buf; > int ret; > > - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); > + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); > if (ret) > return ret; > > @@ -1047,7 +1047,7 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr, > struct resource *res = &pdev->resource[bar]; > int ret; > > - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); > + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); > if (ret) > return ret; > > @@ -1128,7 +1128,7 @@ static ssize_t pci_write_resource_io(struct file *filp, struct kobject *kobj, > { > int ret; > > - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); > + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); > if (ret) > return ret; > > diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c > index cb18f8a13ab6..1dbdcdf0eff5 100644 > --- a/drivers/pci/proc.c > +++ b/drivers/pci/proc.c > @@ -119,7 +119,7 @@ static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf, > int size = dev->cfg_size; > int cnt, ret; > > - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); > + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); > if (ret) > return ret; > > @@ -202,7 +202,7 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd, > #endif /* HAVE_PCI_MMAP */ > int ret = 0; > > - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); > + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); > if (ret) > return ret; > > @@ -249,7 +249,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) > int i, ret, write_combine = 0, res_bit = IORESOURCE_MEM; > > if (!capable(CAP_SYS_RAWIO) || > - security_locked_down(LOCKDOWN_PCI_ACCESS)) > + security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS)) > return -EPERM; > > if (fpriv->mmap_state == pci_mmap_io) { > diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c > index 61a6fe3cde21..e88cacf8d418 100644 > --- a/drivers/pci/syscall.c > +++ b/drivers/pci/syscall.c > @@ -93,7 +93,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn, > int err = 0; > > if (!capable(CAP_SYS_ADMIN) || > - security_locked_down(LOCKDOWN_PCI_ACCESS)) > + security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS)) > return -EPERM; > > dev = pci_get_domain_bus_and_slot(0, bus, dfn); > diff --git a/drivers/pcmcia/cistpl.c b/drivers/pcmcia/cistpl.c > index 948b763dc451..96c96c1cd6da 100644 > --- a/drivers/pcmcia/cistpl.c > +++ b/drivers/pcmcia/cistpl.c > @@ -1577,7 +1577,7 @@ static ssize_t pccard_store_cis(struct file *filp, struct kobject *kobj, > struct pcmcia_socket *s; > int error; > > - error = security_locked_down(LOCKDOWN_PCMCIA_CIS); > + error = security_locked_down(current_cred(), LOCKDOWN_PCMCIA_CIS); > if (error) > return error; > > diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c > index 0e2e35ab64c7..7fbec2644b1b 100644 > --- a/drivers/tty/serial/serial_core.c > +++ b/drivers/tty/serial/serial_core.c > @@ -840,7 +840,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, > } > > if (change_irq || change_port) { > - retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); > + retval = security_locked_down(current_cred(), LOCKDOWN_TIOCSSERIAL); > if (retval) > goto exit; > } > diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c > index 7d162b0efbf0..a8e44f3e11d2 100644 > --- a/fs/debugfs/file.c > +++ b/fs/debugfs/file.c > @@ -154,7 +154,7 @@ static int debugfs_locked_down(struct inode *inode, > !real_fops->mmap) > return 0; > > - if (security_locked_down(LOCKDOWN_DEBUGFS)) > + if (security_locked_down(current_cred(), LOCKDOWN_DEBUGFS)) > return -EPERM; > > return 0; > diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c > index 8129a430d789..17f6438cc1b5 100644 > --- a/fs/debugfs/inode.c > +++ b/fs/debugfs/inode.c > @@ -48,7 +48,7 @@ static int debugfs_setattr(struct user_namespace *mnt_userns, > int ret; > > if (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) { > - ret = security_locked_down(LOCKDOWN_DEBUGFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_DEBUGFS); > if (ret) > return ret; > } > diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c > index 982e694aae77..f386fd373ea6 100644 > --- a/fs/proc/kcore.c > +++ b/fs/proc/kcore.c > @@ -586,7 +586,7 @@ out: > > static int open_kcore(struct inode *inode, struct file *filp) > { > - int ret = security_locked_down(LOCKDOWN_KCORE); > + int ret = security_locked_down(current_cred(), LOCKDOWN_KCORE); > > if (!capable(CAP_SYS_RAWIO)) > return -EPERM; > diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c > index 1261e8b41edb..9db8dd52d429 100644 > --- a/fs/tracefs/inode.c > +++ b/fs/tracefs/inode.c > @@ -396,7 +396,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, > struct dentry *dentry; > struct inode *inode; > > - if (security_locked_down(LOCKDOWN_TRACEFS)) > + if (security_locked_down(NULL, LOCKDOWN_TRACEFS)) > return NULL; > > if (!(mode & S_IFMT)) > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h > index 2adeea44c0d5..a83a370cc284 100644 > --- a/include/linux/lsm_hook_defs.h > +++ b/include/linux/lsm_hook_defs.h > @@ -393,7 +393,7 @@ LSM_HOOK(int, 0, bpf_prog_alloc_security, struct bpf_prog_aux *aux) > LSM_HOOK(void, LSM_RET_VOID, bpf_prog_free_security, struct bpf_prog_aux *aux) > #endif /* CONFIG_BPF_SYSCALL */ > > -LSM_HOOK(int, 0, locked_down, enum lockdown_reason what) > +LSM_HOOK(int, 0, locked_down, const struct cred *cred, enum lockdown_reason what) > > #ifdef CONFIG_PERF_EVENTS > LSM_HOOK(int, 0, perf_event_open, struct perf_event_attr *attr, int type) > diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h > index 5c4c5c0602cb..8156f2dbaab7 100644 > --- a/include/linux/lsm_hooks.h > +++ b/include/linux/lsm_hooks.h > @@ -1543,6 +1543,7 @@ > * Determine whether a kernel feature that potentially enables arbitrary > * code execution in kernel space should be permitted. > * > + * @cred: credential asociated with the operation, or NULL if not applicable > * @what: kernel feature being accessed > * > * Security hooks for perf events > diff --git a/include/linux/security.h b/include/linux/security.h > index 5b7288521300..a9001c0ed885 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -471,7 +471,7 @@ void security_inode_invalidate_secctx(struct inode *inode); > int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); > int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); > int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); > -int security_locked_down(enum lockdown_reason what); > +int security_locked_down(const struct cred *cred, enum lockdown_reason what); > #else /* CONFIG_SECURITY */ > > static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data) > @@ -1344,7 +1344,7 @@ static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 > { > return -EOPNOTSUPP; > } > -static inline int security_locked_down(enum lockdown_reason what) > +static inline int security_locked_down(struct cred *cred, enum lockdown_reason what) > { > return 0; > } > diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c > index 9aabf84afd4b..61a9645f9b8f 100644 > --- a/kernel/bpf/helpers.c > +++ b/kernel/bpf/helpers.c > @@ -1424,13 +1424,15 @@ bpf_base_func_proto(enum bpf_func_id func_id) > case BPF_FUNC_probe_read_user: > return &bpf_probe_read_user_proto; > case BPF_FUNC_probe_read_kernel: > - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? > - NULL : &bpf_probe_read_kernel_proto; > + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) > + return NULL; > + return &bpf_probe_read_kernel_proto; > case BPF_FUNC_probe_read_user_str: > return &bpf_probe_read_user_str_proto; > case BPF_FUNC_probe_read_kernel_str: > - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? > - NULL : &bpf_probe_read_kernel_str_proto; > + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) > + return NULL; > + return &bpf_probe_read_kernel_str_proto; > case BPF_FUNC_snprintf_btf: > return &bpf_snprintf_btf_proto; > case BPF_FUNC_snprintf: > diff --git a/kernel/events/core.c b/kernel/events/core.c > index 744e8726c5b2..d2836e320948 100644 > --- a/kernel/events/core.c > +++ b/kernel/events/core.c > @@ -12017,7 +12017,7 @@ SYSCALL_DEFINE5(perf_event_open, > > /* REGS_INTR can leak data, lockdown must prevent this */ > if (attr.sample_type & PERF_SAMPLE_REGS_INTR) { > - err = security_locked_down(LOCKDOWN_PERF); > + err = security_locked_down(current_cred(), LOCKDOWN_PERF); > if (err) > return err; > } > diff --git a/kernel/kexec.c b/kernel/kexec.c > index b5e40f069768..f908dd7889de 100644 > --- a/kernel/kexec.c > +++ b/kernel/kexec.c > @@ -208,7 +208,7 @@ static inline int kexec_load_check(unsigned long nr_segments, > * kexec can be used to circumvent module loading restrictions, so > * prevent loading in that case > */ > - result = security_locked_down(LOCKDOWN_KEXEC); > + result = security_locked_down(current_cred(), LOCKDOWN_KEXEC); > if (result) > return result; > > diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c > index 33400ff051a8..add00b325f4f 100644 > --- a/kernel/kexec_file.c > +++ b/kernel/kexec_file.c > @@ -204,7 +204,7 @@ kimage_validate_signature(struct kimage *image) > * down. > */ > if (!ima_appraise_signature(READING_KEXEC_IMAGE) && > - security_locked_down(LOCKDOWN_KEXEC)) > + security_locked_down(current_cred(), LOCKDOWN_KEXEC)) > return -EPERM; > > pr_debug("kernel signature verification failed (%d).\n", ret); > diff --git a/kernel/module.c b/kernel/module.c > index 40ec9a030eec..3cad8055d7a2 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -2931,7 +2931,7 @@ static int module_sig_check(struct load_info *info, int flags) > return -EKEYREJECTED; > } > > - return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); > + return security_locked_down(current_cred(), LOCKDOWN_MODULE_SIGNATURE); > } > #else /* !CONFIG_MODULE_SIG */ > static int module_sig_check(struct load_info *info, int flags) > diff --git a/kernel/params.c b/kernel/params.c > index 8299bd764e42..619bf8ad8416 100644 > --- a/kernel/params.c > +++ b/kernel/params.c > @@ -100,7 +100,7 @@ bool parameq(const char *a, const char *b) > static bool param_check_unsafe(const struct kernel_param *kp) > { > if (kp->flags & KERNEL_PARAM_FL_HWPARAM && > - security_locked_down(LOCKDOWN_MODULE_PARAMETERS)) > + security_locked_down(current_cred(), LOCKDOWN_MODULE_PARAMETERS)) > return false; > > if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { > diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c > index 559acef3fddb..2625d531ee0e 100644 > --- a/kernel/power/hibernate.c > +++ b/kernel/power/hibernate.c > @@ -83,7 +83,7 @@ void hibernate_release(void) > bool hibernation_available(void) > { > return nohibernate == 0 && > - !security_locked_down(LOCKDOWN_HIBERNATION) && > + !security_locked_down(current_cred(), LOCKDOWN_HIBERNATION) && > !secretmem_active(); > } > > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c > index 8e2eb950aa82..51bdbdf75a5c 100644 > --- a/kernel/trace/bpf_trace.c > +++ b/kernel/trace/bpf_trace.c > @@ -1066,25 +1066,30 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) > case BPF_FUNC_get_prandom_u32: > return &bpf_get_prandom_u32_proto; > case BPF_FUNC_probe_write_user: > - return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? > - NULL : bpf_get_probe_write_proto(); > + if (security_locked_down(current_cred(), LOCKDOWN_BPF_WRITE_USER) < 0) > + return NULL; > + return bpf_get_probe_write_proto(); > case BPF_FUNC_probe_read_user: > return &bpf_probe_read_user_proto; > case BPF_FUNC_probe_read_kernel: > - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? > - NULL : &bpf_probe_read_kernel_proto; > + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) > + return NULL; > + return &bpf_probe_read_kernel_proto; > case BPF_FUNC_probe_read_user_str: > return &bpf_probe_read_user_str_proto; > case BPF_FUNC_probe_read_kernel_str: > - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? > - NULL : &bpf_probe_read_kernel_str_proto; > + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) > + return NULL; > + return &bpf_probe_read_kernel_str_proto; > #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE > case BPF_FUNC_probe_read: > - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? > - NULL : &bpf_probe_read_compat_proto; > + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) > + return NULL; > + return &bpf_probe_read_compat_proto; > case BPF_FUNC_probe_read_str: > - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? > - NULL : &bpf_probe_read_compat_str_proto; > + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) > + return NULL; > + return &bpf_probe_read_compat_str_proto; > #endif > #ifdef CONFIG_CGROUPS > case BPF_FUNC_get_current_cgroup_id: > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c > index 7efbc8aaf7f6..5c1b2681c371 100644 > --- a/kernel/trace/ftrace.c > +++ b/kernel/trace/ftrace.c > @@ -3694,7 +3694,7 @@ ftrace_avail_open(struct inode *inode, struct file *file) > struct ftrace_iterator *iter; > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > @@ -5822,7 +5822,7 @@ __ftrace_graph_open(struct inode *inode, struct file *file, > int ret; > struct ftrace_hash *new_hash = NULL; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c > index c5a3fbf19617..13669fcbd466 100644 > --- a/kernel/trace/ring_buffer.c > +++ b/kernel/trace/ring_buffer.c > @@ -5880,7 +5880,7 @@ static __init int test_ringbuffer(void) > int cpu; > int ret = 0; > > - if (security_locked_down(LOCKDOWN_TRACEFS)) { > + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { > pr_warn("Lockdown is enabled, skipping ring buffer tests\n"); > return 0; > } > diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c > index 7896d30d90f7..2bac9688ff6a 100644 > --- a/kernel/trace/trace.c > +++ b/kernel/trace/trace.c > @@ -486,7 +486,7 @@ int tracing_check_open_get_tr(struct trace_array *tr) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > @@ -2071,7 +2071,7 @@ int __init register_tracer(struct tracer *type) > return -1; > } > > - if (security_locked_down(LOCKDOWN_TRACEFS)) { > + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { > pr_warn("Can not register tracer %s due to lockdown\n", > type->name); > return -EPERM; > @@ -9527,7 +9527,7 @@ int tracing_init_dentry(void) > { > struct trace_array *tr = &global_trace; > > - if (security_locked_down(LOCKDOWN_TRACEFS)) { > + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { > pr_warn("Tracing disabled due to lockdown\n"); > return -EPERM; > } > @@ -9989,7 +9989,7 @@ __init static int tracer_alloc_buffers(void) > int ret = -ENOMEM; > > > - if (security_locked_down(LOCKDOWN_TRACEFS)) { > + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { > pr_warn("Tracing disabled due to lockdown\n"); > return -EPERM; > } > @@ -10155,7 +10155,7 @@ __init static void tracing_set_default_clock(void) > { > /* sched_clock_stable() is determined in late_initcall */ > if (!trace_boot_clock && !sched_clock_stable()) { > - if (security_locked_down(LOCKDOWN_TRACEFS)) { > + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { > pr_warn("Can not set tracing clock due to lockdown\n"); > return; > } > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > index 830b3b9940f4..c1e4f7f93c0e 100644 > --- a/kernel/trace/trace_events.c > +++ b/kernel/trace/trace_events.c > @@ -2130,7 +2130,7 @@ ftrace_event_open(struct inode *inode, struct file *file, > struct seq_file *m; > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c > index a6061a69aa84..e122f0467421 100644 > --- a/kernel/trace/trace_events_hist.c > +++ b/kernel/trace/trace_events_hist.c > @@ -4917,7 +4917,7 @@ static int event_hist_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > @@ -5189,7 +5189,7 @@ static int event_hist_debug_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c > index d54094b7a9d7..deac45f00f3a 100644 > --- a/kernel/trace/trace_events_synth.c > +++ b/kernel/trace/trace_events_synth.c > @@ -2174,7 +2174,7 @@ static int synth_events_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c > index 3d5c07239a2a..38226c386f82 100644 > --- a/kernel/trace/trace_events_trigger.c > +++ b/kernel/trace/trace_events_trigger.c > @@ -190,7 +190,7 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 3a64ba4bbad6..9178ad52290e 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -479,7 +479,7 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) > { > int i, ret; > > - ret = security_locked_down(LOCKDOWN_KPROBES); > + ret = security_locked_down(current_cred(), LOCKDOWN_KPROBES); > if (ret) > return ret; > > @@ -1141,7 +1141,7 @@ static int probes_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > @@ -1199,7 +1199,7 @@ static int profile_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c > index 4b320fe7df70..47c808484cb2 100644 > --- a/kernel/trace/trace_printk.c > +++ b/kernel/trace/trace_printk.c > @@ -362,7 +362,7 @@ ftrace_formats_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c > index 63c285042051..63b6ebe7bdce 100644 > --- a/kernel/trace/trace_stack.c > +++ b/kernel/trace/trace_stack.c > @@ -477,7 +477,7 @@ static int stack_trace_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c > index 8d141c3825a9..2f6ae81ee67e 100644 > --- a/kernel/trace/trace_stat.c > +++ b/kernel/trace/trace_stat.c > @@ -236,7 +236,7 @@ static int tracing_stat_open(struct inode *inode, struct file *file) > struct seq_file *m; > struct stat_session *session = inode->i_private; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 225ce569bf8f..4b114e4fe436 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -781,7 +781,7 @@ static int probes_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > @@ -836,7 +836,7 @@ static int profile_open(struct inode *inode, struct file *file) > { > int ret; > > - ret = security_locked_down(LOCKDOWN_TRACEFS); > + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); > if (ret) > return ret; > > diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c > index 03b66d154b2b..ffd560514d8f 100644 > --- a/net/xfrm/xfrm_user.c > +++ b/net/xfrm/xfrm_user.c > @@ -850,8 +850,15 @@ static int copy_user_offload(struct xfrm_state_offload *xso, struct sk_buff *skb > > static bool xfrm_redact(void) > { > - return IS_ENABLED(CONFIG_SECURITY) && > - security_locked_down(LOCKDOWN_XFRM_SECRET); > + /* Don't use current_cred() here, since this may be called when > + * broadcasting a notification that an SA has been created/deleted. > + * In that case current task is the one triggering the notification, > + * but the SA key is actually leaked to the event subscribers. > + * Since we can't easily do the redact decision per-subscriber, > + * just pass NULL here, indicating to the LSMs that a global lockdown > + * decision should be made instead. > + */ > + return security_locked_down(NULL, LOCKDOWN_XFRM_SECRET); > } > > static int copy_to_user_auth(struct xfrm_algo_auth *auth, struct sk_buff *skb) > diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c > index 87cbdc64d272..2abe92157e82 100644 > --- a/security/lockdown/lockdown.c > +++ b/security/lockdown/lockdown.c > @@ -55,7 +55,8 @@ early_param("lockdown", lockdown_param); > * lockdown_is_locked_down - Find out if the kernel is locked down > * @what: Tag to use in notice generated if lockdown is in effect > */ > -static int lockdown_is_locked_down(enum lockdown_reason what) > +static int lockdown_is_locked_down(const struct cred *cred, > + enum lockdown_reason what) > { > if (WARN(what >= LOCKDOWN_CONFIDENTIALITY_MAX, > "Invalid lockdown reason")) > diff --git a/security/security.c b/security/security.c > index 9ffa9e9c5c55..51245e37b351 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -2593,9 +2593,9 @@ void security_bpf_prog_free(struct bpf_prog_aux *aux) > } > #endif /* CONFIG_BPF_SYSCALL */ > > -int security_locked_down(enum lockdown_reason what) > +int security_locked_down(const struct cred *cred, enum lockdown_reason what) > { > - return call_int_hook(locked_down, 0, what); > + return call_int_hook(locked_down, 0, cred, what); > } > EXPORT_SYMBOL(security_locked_down); > > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 6517f221d52c..300bc9e1ffbf 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -7013,10 +7013,10 @@ static void selinux_bpf_prog_free(struct bpf_prog_aux *aux) > } > #endif > > -static int selinux_lockdown(enum lockdown_reason what) > +static int selinux_lockdown(const struct cred *cred, enum lockdown_reason what) > { > struct common_audit_data ad; > - u32 sid = current_sid(); > + u32 sid; > int invalid_reason = (what <= LOCKDOWN_NONE) || > (what == LOCKDOWN_INTEGRITY_MAX) || > (what >= LOCKDOWN_CONFIDENTIALITY_MAX); > @@ -7028,6 +7028,9 @@ static int selinux_lockdown(enum lockdown_reason what) > return -EINVAL; > } > > + /* Use SECINITSID_KERNEL if there is no relevant cred to check against */ > + sid = cred ? cred_sid(cred) : SECINITSID_KERNEL; > + > ad.type = LSM_AUDIT_DATA_LOCKDOWN; > ad.u.reason = what; > > -- > 2.31.1 >
On Mon, Sep 13, 2021 at 5:05 PM Paul Moore <paul@paul-moore.com> wrote: > > On Mon, Sep 13, 2021 at 10:02 AM Ondrej Mosnacek <omosnace@redhat.com> wrote: > > > > Commit 59438b46471a ("security,lockdown,selinux: implement SELinux > > lockdown") added an implementation of the locked_down LSM hook to > > SELinux, with the aim to restrict which domains are allowed to perform > > operations that would breach lockdown. > > > > However, in several places the security_locked_down() hook is called in > > situations where the current task isn't doing any action that would > > directly breach lockdown, leading to SELinux checks that are basically > > bogus. > > > > To fix this, add an explicit struct cred pointer argument to > > security_lockdown() and define NULL as a special value to pass instead > > of current_cred() in such situations. LSMs that take the subject > > credentials into account can then fall back to some default or ignore > > such calls altogether. In the SELinux lockdown hook implementation, use > > SECINITSID_KERNEL in case the cred argument is NULL. > > > > Most of the callers are updated to pass current_cred() as the cred > > pointer, thus maintaining the same behavior. The following callers are > > modified to pass NULL as the cred pointer instead: > > 1. arch/powerpc/xmon/xmon.c > > Seems to be some interactive debugging facility. It appears that > > the lockdown hook is called from interrupt context here, so it > > should be more appropriate to request a global lockdown decision. > > 2. fs/tracefs/inode.c:tracefs_create_file() > > Here the call is used to prevent creating new tracefs entries when > > the kernel is locked down. Assumes that locking down is one-way - > > i.e. if the hook returns non-zero once, it will never return zero > > again, thus no point in creating these files. Also, the hook is > > often called by a module's init function when it is loaded by > > userspace, where it doesn't make much sense to do a check against > > the current task's creds, since the task itself doesn't actually > > use the tracing functionality (i.e. doesn't breach lockdown), just > > indirectly makes some new tracepoints available to whoever is > > authorized to use them. > > 3. net/xfrm/xfrm_user.c:copy_to_user_*() > > Here a cryptographic secret is redacted based on the value returned > > from the hook. There are two possible actions that may lead here: > > a) A netlink message XFRM_MSG_GETSA with NLM_F_DUMP set - here the > > task context is relevant, since the dumped data is sent back to > > the current task. > > b) When adding/deleting/updating an SA via XFRM_MSG_xxxSA, the > > dumped SA is broadcasted to tasks subscribed to XFRM events - > > here the current task context is not relevant as it doesn't > > represent the tasks that could potentially see the secret. > > It doesn't seem worth it to try to keep using the current task's > > context in the a) case, since the eventual data leak can be > > circumvented anyway via b), plus there is no way for the task to > > indicate that it doesn't care about the actual key value, so the > > check could generate a lot of "false alert" denials with SELinux. > > Thus, let's pass NULL instead of current_cred() here faute de > > mieux. > > > > Improvements-suggested-by: Casey Schaufler <casey@schaufler-ca.com> > > Improvements-suggested-by: Paul Moore <paul@paul-moore.com> > > Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") > > Acked-by: Dan Williams <dan.j.williams@intel.com> [cxl] > > Acked-by: Steffen Klassert <steffen.klassert@secunet.com> [xfrm] > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> > > --- > > > > v4: > > - rebase on top of TODO > > - fix rebase conflicts: > > * drivers/cxl/pci.c > > - trivial: the lockdown reason was corrected in mainline > > * kernel/bpf/helpers.c, kernel/trace/bpf_trace.c > > - trivial: LOCKDOWN_BPF_READ was renamed to LOCKDOWN_BPF_READ_KERNEL > > in mainline > > * kernel/power/hibernate.c > > - trivial: !secretmem_active() was added to the condition in > > hibernation_available() > > - cover new security_locked_down() call in kernel/bpf/helpers.c > > (LOCKDOWN_BPF_WRITE_USER in BPF_FUNC_probe_write_user case) > > > > v3: https://lore.kernel.org/lkml/20210616085118.1141101-1-omosnace@redhat.com/ > > - add the cred argument to security_locked_down() and adapt all callers > > - keep using current_cred() in BPF, as the hook calls have been shifted > > to program load time (commit ff40e51043af ("bpf, lockdown, audit: Fix > > buggy SELinux lockdown permission checks")) > > - in SELinux, don't ignore hook calls where cred == NULL, but use > > SECINITSID_KERNEL as the subject instead > > - update explanations in the commit message > > > > v2: https://lore.kernel.org/lkml/20210517092006.803332-1-omosnace@redhat.com/ > > - change to a single hook based on suggestions by Casey Schaufler > > > > v1: https://lore.kernel.org/lkml/20210507114048.138933-1-omosnace@redhat.com/ > > The changes between v3 and v4 all seem sane to me, but I'm going to > let this sit for a few days in hopes that we can collect a few more > Reviewed-bys and ACKs. If I don't see any objections I'll merge it > mid-week(ish) into selinux/stable-5.15 and plan on sending it to Linus > after it goes through a build/test cycle. Time's up, I just merged this into selinux/stable-5.15 and I'll send this to Linus once it passes testing. -- paul moore www.paul-moore.com
On Thu, Sep 16, 2021 at 4:59 AM Paul Moore <paul@paul-moore.com> wrote: > On Mon, Sep 13, 2021 at 5:05 PM Paul Moore <paul@paul-moore.com> wrote: > > > > On Mon, Sep 13, 2021 at 10:02 AM Ondrej Mosnacek <omosnace@redhat.com> wrote: > > > > > > Commit 59438b46471a ("security,lockdown,selinux: implement SELinux > > > lockdown") added an implementation of the locked_down LSM hook to > > > SELinux, with the aim to restrict which domains are allowed to perform > > > operations that would breach lockdown. > > > > > > However, in several places the security_locked_down() hook is called in > > > situations where the current task isn't doing any action that would > > > directly breach lockdown, leading to SELinux checks that are basically > > > bogus. > > > > > > To fix this, add an explicit struct cred pointer argument to > > > security_lockdown() and define NULL as a special value to pass instead > > > of current_cred() in such situations. LSMs that take the subject > > > credentials into account can then fall back to some default or ignore > > > such calls altogether. In the SELinux lockdown hook implementation, use > > > SECINITSID_KERNEL in case the cred argument is NULL. > > > > > > Most of the callers are updated to pass current_cred() as the cred > > > pointer, thus maintaining the same behavior. The following callers are > > > modified to pass NULL as the cred pointer instead: > > > 1. arch/powerpc/xmon/xmon.c > > > Seems to be some interactive debugging facility. It appears that > > > the lockdown hook is called from interrupt context here, so it > > > should be more appropriate to request a global lockdown decision. > > > 2. fs/tracefs/inode.c:tracefs_create_file() > > > Here the call is used to prevent creating new tracefs entries when > > > the kernel is locked down. Assumes that locking down is one-way - > > > i.e. if the hook returns non-zero once, it will never return zero > > > again, thus no point in creating these files. Also, the hook is > > > often called by a module's init function when it is loaded by > > > userspace, where it doesn't make much sense to do a check against > > > the current task's creds, since the task itself doesn't actually > > > use the tracing functionality (i.e. doesn't breach lockdown), just > > > indirectly makes some new tracepoints available to whoever is > > > authorized to use them. > > > 3. net/xfrm/xfrm_user.c:copy_to_user_*() > > > Here a cryptographic secret is redacted based on the value returned > > > from the hook. There are two possible actions that may lead here: > > > a) A netlink message XFRM_MSG_GETSA with NLM_F_DUMP set - here the > > > task context is relevant, since the dumped data is sent back to > > > the current task. > > > b) When adding/deleting/updating an SA via XFRM_MSG_xxxSA, the > > > dumped SA is broadcasted to tasks subscribed to XFRM events - > > > here the current task context is not relevant as it doesn't > > > represent the tasks that could potentially see the secret. > > > It doesn't seem worth it to try to keep using the current task's > > > context in the a) case, since the eventual data leak can be > > > circumvented anyway via b), plus there is no way for the task to > > > indicate that it doesn't care about the actual key value, so the > > > check could generate a lot of "false alert" denials with SELinux. > > > Thus, let's pass NULL instead of current_cred() here faute de > > > mieux. > > > > > > Improvements-suggested-by: Casey Schaufler <casey@schaufler-ca.com> > > > Improvements-suggested-by: Paul Moore <paul@paul-moore.com> > > > Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") > > > Acked-by: Dan Williams <dan.j.williams@intel.com> [cxl] > > > Acked-by: Steffen Klassert <steffen.klassert@secunet.com> [xfrm] > > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> > > > --- > > > > > > v4: > > > - rebase on top of TODO > > > - fix rebase conflicts: > > > * drivers/cxl/pci.c > > > - trivial: the lockdown reason was corrected in mainline > > > * kernel/bpf/helpers.c, kernel/trace/bpf_trace.c > > > - trivial: LOCKDOWN_BPF_READ was renamed to LOCKDOWN_BPF_READ_KERNEL > > > in mainline > > > * kernel/power/hibernate.c > > > - trivial: !secretmem_active() was added to the condition in > > > hibernation_available() > > > - cover new security_locked_down() call in kernel/bpf/helpers.c > > > (LOCKDOWN_BPF_WRITE_USER in BPF_FUNC_probe_write_user case) > > > > > > v3: https://lore.kernel.org/lkml/20210616085118.1141101-1-omosnace@redhat.com/ > > > - add the cred argument to security_locked_down() and adapt all callers > > > - keep using current_cred() in BPF, as the hook calls have been shifted > > > to program load time (commit ff40e51043af ("bpf, lockdown, audit: Fix > > > buggy SELinux lockdown permission checks")) > > > - in SELinux, don't ignore hook calls where cred == NULL, but use > > > SECINITSID_KERNEL as the subject instead > > > - update explanations in the commit message > > > > > > v2: https://lore.kernel.org/lkml/20210517092006.803332-1-omosnace@redhat.com/ > > > - change to a single hook based on suggestions by Casey Schaufler > > > > > > v1: https://lore.kernel.org/lkml/20210507114048.138933-1-omosnace@redhat.com/ > > > > The changes between v3 and v4 all seem sane to me, but I'm going to > > let this sit for a few days in hopes that we can collect a few more > > Reviewed-bys and ACKs. If I don't see any objections I'll merge it > > mid-week(ish) into selinux/stable-5.15 and plan on sending it to Linus > > after it goes through a build/test cycle. > > Time's up, I just merged this into selinux/stable-5.15 and I'll send > this to Linus once it passes testing. Thanks!
On Wed, Sep 15, 2021 at 10:59 PM Paul Moore <paul@paul-moore.com> wrote: > > On Mon, Sep 13, 2021 at 5:05 PM Paul Moore <paul@paul-moore.com> wrote: > > > > On Mon, Sep 13, 2021 at 10:02 AM Ondrej Mosnacek <omosnace@redhat.com> wrote: > > > > > > Commit 59438b46471a ("security,lockdown,selinux: implement SELinux > > > lockdown") added an implementation of the locked_down LSM hook to > > > SELinux, with the aim to restrict which domains are allowed to perform > > > operations that would breach lockdown. > > > > > > However, in several places the security_locked_down() hook is called in > > > situations where the current task isn't doing any action that would > > > directly breach lockdown, leading to SELinux checks that are basically > > > bogus. > > > > > > To fix this, add an explicit struct cred pointer argument to > > > security_lockdown() and define NULL as a special value to pass instead > > > of current_cred() in such situations. LSMs that take the subject > > > credentials into account can then fall back to some default or ignore > > > such calls altogether. In the SELinux lockdown hook implementation, use > > > SECINITSID_KERNEL in case the cred argument is NULL. > > > > > > Most of the callers are updated to pass current_cred() as the cred > > > pointer, thus maintaining the same behavior. The following callers are > > > modified to pass NULL as the cred pointer instead: > > > 1. arch/powerpc/xmon/xmon.c > > > Seems to be some interactive debugging facility. It appears that > > > the lockdown hook is called from interrupt context here, so it > > > should be more appropriate to request a global lockdown decision. > > > 2. fs/tracefs/inode.c:tracefs_create_file() > > > Here the call is used to prevent creating new tracefs entries when > > > the kernel is locked down. Assumes that locking down is one-way - > > > i.e. if the hook returns non-zero once, it will never return zero > > > again, thus no point in creating these files. Also, the hook is > > > often called by a module's init function when it is loaded by > > > userspace, where it doesn't make much sense to do a check against > > > the current task's creds, since the task itself doesn't actually > > > use the tracing functionality (i.e. doesn't breach lockdown), just > > > indirectly makes some new tracepoints available to whoever is > > > authorized to use them. > > > 3. net/xfrm/xfrm_user.c:copy_to_user_*() > > > Here a cryptographic secret is redacted based on the value returned > > > from the hook. There are two possible actions that may lead here: > > > a) A netlink message XFRM_MSG_GETSA with NLM_F_DUMP set - here the > > > task context is relevant, since the dumped data is sent back to > > > the current task. > > > b) When adding/deleting/updating an SA via XFRM_MSG_xxxSA, the > > > dumped SA is broadcasted to tasks subscribed to XFRM events - > > > here the current task context is not relevant as it doesn't > > > represent the tasks that could potentially see the secret. > > > It doesn't seem worth it to try to keep using the current task's > > > context in the a) case, since the eventual data leak can be > > > circumvented anyway via b), plus there is no way for the task to > > > indicate that it doesn't care about the actual key value, so the > > > check could generate a lot of "false alert" denials with SELinux. > > > Thus, let's pass NULL instead of current_cred() here faute de > > > mieux. > > > > > > Improvements-suggested-by: Casey Schaufler <casey@schaufler-ca.com> > > > Improvements-suggested-by: Paul Moore <paul@paul-moore.com> > > > Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") > > > Acked-by: Dan Williams <dan.j.williams@intel.com> [cxl] > > > Acked-by: Steffen Klassert <steffen.klassert@secunet.com> [xfrm] > > > Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> > > > --- > > > > > > v4: > > > - rebase on top of TODO > > > - fix rebase conflicts: > > > * drivers/cxl/pci.c > > > - trivial: the lockdown reason was corrected in mainline > > > * kernel/bpf/helpers.c, kernel/trace/bpf_trace.c > > > - trivial: LOCKDOWN_BPF_READ was renamed to LOCKDOWN_BPF_READ_KERNEL > > > in mainline > > > * kernel/power/hibernate.c > > > - trivial: !secretmem_active() was added to the condition in > > > hibernation_available() > > > - cover new security_locked_down() call in kernel/bpf/helpers.c > > > (LOCKDOWN_BPF_WRITE_USER in BPF_FUNC_probe_write_user case) > > > > > > v3: https://lore.kernel.org/lkml/20210616085118.1141101-1-omosnace@redhat.com/ > > > - add the cred argument to security_locked_down() and adapt all callers > > > - keep using current_cred() in BPF, as the hook calls have been shifted > > > to program load time (commit ff40e51043af ("bpf, lockdown, audit: Fix > > > buggy SELinux lockdown permission checks")) > > > - in SELinux, don't ignore hook calls where cred == NULL, but use > > > SECINITSID_KERNEL as the subject instead > > > - update explanations in the commit message > > > > > > v2: https://lore.kernel.org/lkml/20210517092006.803332-1-omosnace@redhat.com/ > > > - change to a single hook based on suggestions by Casey Schaufler > > > > > > v1: https://lore.kernel.org/lkml/20210507114048.138933-1-omosnace@redhat.com/ > > > > The changes between v3 and v4 all seem sane to me, but I'm going to > > let this sit for a few days in hopes that we can collect a few more > > Reviewed-bys and ACKs. If I don't see any objections I'll merge it > > mid-week(ish) into selinux/stable-5.15 and plan on sending it to Linus > > after it goes through a build/test cycle. > > Time's up, I just merged this into selinux/stable-5.15 and I'll send > this to Linus once it passes testing. ... and it's back out of selinux/stable-5.15 in spectacular fashion. I'll be following up with another SELinux patch today or tomorrow. -- paul moore www.paul-moore.com
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c index dd8241c009e5..47464e873749 100644 --- a/arch/powerpc/xmon/xmon.c +++ b/arch/powerpc/xmon/xmon.c @@ -309,7 +309,7 @@ static bool xmon_is_locked_down(void) static bool lockdown; if (!lockdown) { - lockdown = !!security_locked_down(LOCKDOWN_XMON_RW); + lockdown = !!security_locked_down(NULL, LOCKDOWN_XMON_RW); if (lockdown) { printf("xmon: Disabled due to kernel lockdown\n"); xmon_is_ro = true; @@ -317,7 +317,7 @@ static bool xmon_is_locked_down(void) } if (!xmon_is_ro) { - xmon_is_ro = !!security_locked_down(LOCKDOWN_XMON_WR); + xmon_is_ro = !!security_locked_down(NULL, LOCKDOWN_XMON_WR); if (xmon_is_ro) printf("xmon: Read-only due to kernel lockdown\n"); } diff --git a/arch/x86/kernel/ioport.c b/arch/x86/kernel/ioport.c index e2fab3ceb09f..838ba45ecc71 100644 --- a/arch/x86/kernel/ioport.c +++ b/arch/x86/kernel/ioport.c @@ -71,7 +71,7 @@ long ksys_ioperm(unsigned long from, unsigned long num, int turn_on) if ((from + num <= from) || (from + num > IO_BITMAP_BITS)) return -EINVAL; if (turn_on && (!capable(CAP_SYS_RAWIO) || - security_locked_down(LOCKDOWN_IOPORT))) + security_locked_down(current_cred(), LOCKDOWN_IOPORT))) return -EPERM; /* @@ -187,7 +187,7 @@ SYSCALL_DEFINE1(iopl, unsigned int, level) /* Trying to gain more privileges? */ if (level > old) { if (!capable(CAP_SYS_RAWIO) || - security_locked_down(LOCKDOWN_IOPORT)) + security_locked_down(current_cred(), LOCKDOWN_IOPORT)) return -EPERM; } diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index ed8ac6bcbafb..6a687d91515b 100644 --- a/arch/x86/kernel/msr.c +++ b/arch/x86/kernel/msr.c @@ -116,7 +116,7 @@ static ssize_t msr_write(struct file *file, const char __user *buf, int err = 0; ssize_t bytes = 0; - err = security_locked_down(LOCKDOWN_MSR); + err = security_locked_down(current_cred(), LOCKDOWN_MSR); if (err) return err; @@ -179,7 +179,7 @@ static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg) err = -EFAULT; break; } - err = security_locked_down(LOCKDOWN_MSR); + err = security_locked_down(current_cred(), LOCKDOWN_MSR); if (err) break; diff --git a/arch/x86/mm/testmmiotrace.c b/arch/x86/mm/testmmiotrace.c index bda73cb7a044..c43a13241ae8 100644 --- a/arch/x86/mm/testmmiotrace.c +++ b/arch/x86/mm/testmmiotrace.c @@ -116,7 +116,7 @@ static void do_test_bulk_ioremapping(void) static int __init init(void) { unsigned long size = (read_far) ? (8 << 20) : (16 << 10); - int ret = security_locked_down(LOCKDOWN_MMIOTRACE); + int ret = security_locked_down(current_cred(), LOCKDOWN_MMIOTRACE); if (ret) return ret; diff --git a/drivers/acpi/acpi_configfs.c b/drivers/acpi/acpi_configfs.c index c970792b11a4..17c4e79b596e 100644 --- a/drivers/acpi/acpi_configfs.c +++ b/drivers/acpi/acpi_configfs.c @@ -26,7 +26,7 @@ static ssize_t acpi_table_aml_write(struct config_item *cfg, { const struct acpi_table_header *header = data; struct acpi_table *table; - int ret = security_locked_down(LOCKDOWN_ACPI_TABLES); + int ret = security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES); if (ret) return ret; diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c index d39a9b474727..8cac7f683245 100644 --- a/drivers/acpi/custom_method.c +++ b/drivers/acpi/custom_method.c @@ -30,7 +30,7 @@ static ssize_t cm_write(struct file *file, const char __user *user_buf, acpi_status status; int ret; - ret = security_locked_down(LOCKDOWN_ACPI_TABLES); + ret = security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES); if (ret) return ret; diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index a43f1521efe6..11c462788db8 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -198,7 +198,8 @@ acpi_physical_address __init acpi_os_get_root_pointer(void) * specific location (if appropriate) so it can be carried * over further kexec()s. */ - if (acpi_rsdp && !security_locked_down(LOCKDOWN_ACPI_TABLES)) { + if (acpi_rsdp && !security_locked_down(current_cred(), + LOCKDOWN_ACPI_TABLES)) { acpi_arch_set_root_pointer(acpi_rsdp); return acpi_rsdp; } diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index f9383736fa0f..6569ccacd24b 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -577,7 +577,7 @@ void __init acpi_table_upgrade(void) if (table_nr == 0) return; - if (security_locked_down(LOCKDOWN_ACPI_TABLES)) { + if (security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES)) { pr_notice("kernel is locked down, ignoring table override\n"); return; } diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 1c596b5cdb27..330749897cd7 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -617,7 +617,7 @@ static int open_port(struct inode *inode, struct file *filp) if (!capable(CAP_SYS_RAWIO)) return -EPERM; - rc = security_locked_down(LOCKDOWN_DEV_MEM); + rc = security_locked_down(current_cred(), LOCKDOWN_DEV_MEM); if (rc) return rc; diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c index 8e45aa07d662..539c91959234 100644 --- a/drivers/cxl/pci.c +++ b/drivers/cxl/pci.c @@ -575,7 +575,7 @@ static bool cxl_mem_raw_command_allowed(u16 opcode) if (!IS_ENABLED(CONFIG_CXL_MEM_RAW_COMMANDS)) return false; - if (security_locked_down(LOCKDOWN_PCI_ACCESS)) + if (security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS)) return false; if (cxl_raw_allow_all) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 847f33ffc4ae..a885b4c38358 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -200,7 +200,7 @@ static void generic_ops_unregister(void) static char efivar_ssdt[EFIVAR_SSDT_NAME_MAX] __initdata; static int __init efivar_ssdt_setup(char *str) { - int ret = security_locked_down(LOCKDOWN_ACPI_TABLES); + int ret = security_locked_down(current_cred(), LOCKDOWN_ACPI_TABLES); if (ret) return ret; diff --git a/drivers/firmware/efi/test/efi_test.c b/drivers/firmware/efi/test/efi_test.c index 47d67bb0a516..942c25843665 100644 --- a/drivers/firmware/efi/test/efi_test.c +++ b/drivers/firmware/efi/test/efi_test.c @@ -722,7 +722,7 @@ static long efi_test_ioctl(struct file *file, unsigned int cmd, static int efi_test_open(struct inode *inode, struct file *file) { - int ret = security_locked_down(LOCKDOWN_EFI_TEST); + int ret = security_locked_down(current_cred(), LOCKDOWN_EFI_TEST); if (ret) return ret; diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c index 7fb5cd17cc98..b76055dbbb03 100644 --- a/drivers/pci/pci-sysfs.c +++ b/drivers/pci/pci-sysfs.c @@ -753,7 +753,7 @@ static ssize_t pci_write_config(struct file *filp, struct kobject *kobj, u8 *data = (u8 *) buf; int ret; - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); if (ret) return ret; @@ -1047,7 +1047,7 @@ static int pci_mmap_resource(struct kobject *kobj, struct bin_attribute *attr, struct resource *res = &pdev->resource[bar]; int ret; - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); if (ret) return ret; @@ -1128,7 +1128,7 @@ static ssize_t pci_write_resource_io(struct file *filp, struct kobject *kobj, { int ret; - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); if (ret) return ret; diff --git a/drivers/pci/proc.c b/drivers/pci/proc.c index cb18f8a13ab6..1dbdcdf0eff5 100644 --- a/drivers/pci/proc.c +++ b/drivers/pci/proc.c @@ -119,7 +119,7 @@ static ssize_t proc_bus_pci_write(struct file *file, const char __user *buf, int size = dev->cfg_size; int cnt, ret; - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); if (ret) return ret; @@ -202,7 +202,7 @@ static long proc_bus_pci_ioctl(struct file *file, unsigned int cmd, #endif /* HAVE_PCI_MMAP */ int ret = 0; - ret = security_locked_down(LOCKDOWN_PCI_ACCESS); + ret = security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS); if (ret) return ret; @@ -249,7 +249,7 @@ static int proc_bus_pci_mmap(struct file *file, struct vm_area_struct *vma) int i, ret, write_combine = 0, res_bit = IORESOURCE_MEM; if (!capable(CAP_SYS_RAWIO) || - security_locked_down(LOCKDOWN_PCI_ACCESS)) + security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS)) return -EPERM; if (fpriv->mmap_state == pci_mmap_io) { diff --git a/drivers/pci/syscall.c b/drivers/pci/syscall.c index 61a6fe3cde21..e88cacf8d418 100644 --- a/drivers/pci/syscall.c +++ b/drivers/pci/syscall.c @@ -93,7 +93,7 @@ SYSCALL_DEFINE5(pciconfig_write, unsigned long, bus, unsigned long, dfn, int err = 0; if (!capable(CAP_SYS_ADMIN) || - security_locked_down(LOCKDOWN_PCI_ACCESS)) + security_locked_down(current_cred(), LOCKDOWN_PCI_ACCESS)) return -EPERM; dev = pci_get_domain_bus_and_slot(0, bus, dfn); diff --git a/drivers/pcmcia/cistpl.c b/drivers/pcmcia/cistpl.c index 948b763dc451..96c96c1cd6da 100644 --- a/drivers/pcmcia/cistpl.c +++ b/drivers/pcmcia/cistpl.c @@ -1577,7 +1577,7 @@ static ssize_t pccard_store_cis(struct file *filp, struct kobject *kobj, struct pcmcia_socket *s; int error; - error = security_locked_down(LOCKDOWN_PCMCIA_CIS); + error = security_locked_down(current_cred(), LOCKDOWN_PCMCIA_CIS); if (error) return error; diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index 0e2e35ab64c7..7fbec2644b1b 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -840,7 +840,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port, } if (change_irq || change_port) { - retval = security_locked_down(LOCKDOWN_TIOCSSERIAL); + retval = security_locked_down(current_cred(), LOCKDOWN_TIOCSSERIAL); if (retval) goto exit; } diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 7d162b0efbf0..a8e44f3e11d2 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -154,7 +154,7 @@ static int debugfs_locked_down(struct inode *inode, !real_fops->mmap) return 0; - if (security_locked_down(LOCKDOWN_DEBUGFS)) + if (security_locked_down(current_cred(), LOCKDOWN_DEBUGFS)) return -EPERM; return 0; diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 8129a430d789..17f6438cc1b5 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -48,7 +48,7 @@ static int debugfs_setattr(struct user_namespace *mnt_userns, int ret; if (ia->ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID)) { - ret = security_locked_down(LOCKDOWN_DEBUGFS); + ret = security_locked_down(current_cred(), LOCKDOWN_DEBUGFS); if (ret) return ret; } diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 982e694aae77..f386fd373ea6 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -586,7 +586,7 @@ out: static int open_kcore(struct inode *inode, struct file *filp) { - int ret = security_locked_down(LOCKDOWN_KCORE); + int ret = security_locked_down(current_cred(), LOCKDOWN_KCORE); if (!capable(CAP_SYS_RAWIO)) return -EPERM; diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 1261e8b41edb..9db8dd52d429 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -396,7 +396,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, struct dentry *dentry; struct inode *inode; - if (security_locked_down(LOCKDOWN_TRACEFS)) + if (security_locked_down(NULL, LOCKDOWN_TRACEFS)) return NULL; if (!(mode & S_IFMT)) diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 2adeea44c0d5..a83a370cc284 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -393,7 +393,7 @@ LSM_HOOK(int, 0, bpf_prog_alloc_security, struct bpf_prog_aux *aux) LSM_HOOK(void, LSM_RET_VOID, bpf_prog_free_security, struct bpf_prog_aux *aux) #endif /* CONFIG_BPF_SYSCALL */ -LSM_HOOK(int, 0, locked_down, enum lockdown_reason what) +LSM_HOOK(int, 0, locked_down, const struct cred *cred, enum lockdown_reason what) #ifdef CONFIG_PERF_EVENTS LSM_HOOK(int, 0, perf_event_open, struct perf_event_attr *attr, int type) diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h index 5c4c5c0602cb..8156f2dbaab7 100644 --- a/include/linux/lsm_hooks.h +++ b/include/linux/lsm_hooks.h @@ -1543,6 +1543,7 @@ * Determine whether a kernel feature that potentially enables arbitrary * code execution in kernel space should be permitted. * + * @cred: credential asociated with the operation, or NULL if not applicable * @what: kernel feature being accessed * * Security hooks for perf events diff --git a/include/linux/security.h b/include/linux/security.h index 5b7288521300..a9001c0ed885 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -471,7 +471,7 @@ void security_inode_invalidate_secctx(struct inode *inode); int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen); int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen); int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen); -int security_locked_down(enum lockdown_reason what); +int security_locked_down(const struct cred *cred, enum lockdown_reason what); #else /* CONFIG_SECURITY */ static inline int call_blocking_lsm_notifier(enum lsm_event event, void *data) @@ -1344,7 +1344,7 @@ static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 { return -EOPNOTSUPP; } -static inline int security_locked_down(enum lockdown_reason what) +static inline int security_locked_down(struct cred *cred, enum lockdown_reason what) { return 0; } diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 9aabf84afd4b..61a9645f9b8f 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -1424,13 +1424,15 @@ bpf_base_func_proto(enum bpf_func_id func_id) case BPF_FUNC_probe_read_user: return &bpf_probe_read_user_proto; case BPF_FUNC_probe_read_kernel: - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? - NULL : &bpf_probe_read_kernel_proto; + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) + return NULL; + return &bpf_probe_read_kernel_proto; case BPF_FUNC_probe_read_user_str: return &bpf_probe_read_user_str_proto; case BPF_FUNC_probe_read_kernel_str: - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? - NULL : &bpf_probe_read_kernel_str_proto; + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) + return NULL; + return &bpf_probe_read_kernel_str_proto; case BPF_FUNC_snprintf_btf: return &bpf_snprintf_btf_proto; case BPF_FUNC_snprintf: diff --git a/kernel/events/core.c b/kernel/events/core.c index 744e8726c5b2..d2836e320948 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -12017,7 +12017,7 @@ SYSCALL_DEFINE5(perf_event_open, /* REGS_INTR can leak data, lockdown must prevent this */ if (attr.sample_type & PERF_SAMPLE_REGS_INTR) { - err = security_locked_down(LOCKDOWN_PERF); + err = security_locked_down(current_cred(), LOCKDOWN_PERF); if (err) return err; } diff --git a/kernel/kexec.c b/kernel/kexec.c index b5e40f069768..f908dd7889de 100644 --- a/kernel/kexec.c +++ b/kernel/kexec.c @@ -208,7 +208,7 @@ static inline int kexec_load_check(unsigned long nr_segments, * kexec can be used to circumvent module loading restrictions, so * prevent loading in that case */ - result = security_locked_down(LOCKDOWN_KEXEC); + result = security_locked_down(current_cred(), LOCKDOWN_KEXEC); if (result) return result; diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index 33400ff051a8..add00b325f4f 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -204,7 +204,7 @@ kimage_validate_signature(struct kimage *image) * down. */ if (!ima_appraise_signature(READING_KEXEC_IMAGE) && - security_locked_down(LOCKDOWN_KEXEC)) + security_locked_down(current_cred(), LOCKDOWN_KEXEC)) return -EPERM; pr_debug("kernel signature verification failed (%d).\n", ret); diff --git a/kernel/module.c b/kernel/module.c index 40ec9a030eec..3cad8055d7a2 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2931,7 +2931,7 @@ static int module_sig_check(struct load_info *info, int flags) return -EKEYREJECTED; } - return security_locked_down(LOCKDOWN_MODULE_SIGNATURE); + return security_locked_down(current_cred(), LOCKDOWN_MODULE_SIGNATURE); } #else /* !CONFIG_MODULE_SIG */ static int module_sig_check(struct load_info *info, int flags) diff --git a/kernel/params.c b/kernel/params.c index 8299bd764e42..619bf8ad8416 100644 --- a/kernel/params.c +++ b/kernel/params.c @@ -100,7 +100,7 @@ bool parameq(const char *a, const char *b) static bool param_check_unsafe(const struct kernel_param *kp) { if (kp->flags & KERNEL_PARAM_FL_HWPARAM && - security_locked_down(LOCKDOWN_MODULE_PARAMETERS)) + security_locked_down(current_cred(), LOCKDOWN_MODULE_PARAMETERS)) return false; if (kp->flags & KERNEL_PARAM_FL_UNSAFE) { diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 559acef3fddb..2625d531ee0e 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -83,7 +83,7 @@ void hibernate_release(void) bool hibernation_available(void) { return nohibernate == 0 && - !security_locked_down(LOCKDOWN_HIBERNATION) && + !security_locked_down(current_cred(), LOCKDOWN_HIBERNATION) && !secretmem_active(); } diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 8e2eb950aa82..51bdbdf75a5c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1066,25 +1066,30 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_get_prandom_u32: return &bpf_get_prandom_u32_proto; case BPF_FUNC_probe_write_user: - return security_locked_down(LOCKDOWN_BPF_WRITE_USER) < 0 ? - NULL : bpf_get_probe_write_proto(); + if (security_locked_down(current_cred(), LOCKDOWN_BPF_WRITE_USER) < 0) + return NULL; + return bpf_get_probe_write_proto(); case BPF_FUNC_probe_read_user: return &bpf_probe_read_user_proto; case BPF_FUNC_probe_read_kernel: - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? - NULL : &bpf_probe_read_kernel_proto; + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) + return NULL; + return &bpf_probe_read_kernel_proto; case BPF_FUNC_probe_read_user_str: return &bpf_probe_read_user_str_proto; case BPF_FUNC_probe_read_kernel_str: - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? - NULL : &bpf_probe_read_kernel_str_proto; + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) + return NULL; + return &bpf_probe_read_kernel_str_proto; #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE case BPF_FUNC_probe_read: - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? - NULL : &bpf_probe_read_compat_proto; + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) + return NULL; + return &bpf_probe_read_compat_proto; case BPF_FUNC_probe_read_str: - return security_locked_down(LOCKDOWN_BPF_READ_KERNEL) < 0 ? - NULL : &bpf_probe_read_compat_str_proto; + if (security_locked_down(current_cred(), LOCKDOWN_BPF_READ_KERNEL) < 0) + return NULL; + return &bpf_probe_read_compat_str_proto; #endif #ifdef CONFIG_CGROUPS case BPF_FUNC_get_current_cgroup_id: diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7efbc8aaf7f6..5c1b2681c371 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3694,7 +3694,7 @@ ftrace_avail_open(struct inode *inode, struct file *file) struct ftrace_iterator *iter; int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; @@ -5822,7 +5822,7 @@ __ftrace_graph_open(struct inode *inode, struct file *file, int ret; struct ftrace_hash *new_hash = NULL; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index c5a3fbf19617..13669fcbd466 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -5880,7 +5880,7 @@ static __init int test_ringbuffer(void) int cpu; int ret = 0; - if (security_locked_down(LOCKDOWN_TRACEFS)) { + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { pr_warn("Lockdown is enabled, skipping ring buffer tests\n"); return 0; } diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7896d30d90f7..2bac9688ff6a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -486,7 +486,7 @@ int tracing_check_open_get_tr(struct trace_array *tr) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; @@ -2071,7 +2071,7 @@ int __init register_tracer(struct tracer *type) return -1; } - if (security_locked_down(LOCKDOWN_TRACEFS)) { + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { pr_warn("Can not register tracer %s due to lockdown\n", type->name); return -EPERM; @@ -9527,7 +9527,7 @@ int tracing_init_dentry(void) { struct trace_array *tr = &global_trace; - if (security_locked_down(LOCKDOWN_TRACEFS)) { + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { pr_warn("Tracing disabled due to lockdown\n"); return -EPERM; } @@ -9989,7 +9989,7 @@ __init static int tracer_alloc_buffers(void) int ret = -ENOMEM; - if (security_locked_down(LOCKDOWN_TRACEFS)) { + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { pr_warn("Tracing disabled due to lockdown\n"); return -EPERM; } @@ -10155,7 +10155,7 @@ __init static void tracing_set_default_clock(void) { /* sched_clock_stable() is determined in late_initcall */ if (!trace_boot_clock && !sched_clock_stable()) { - if (security_locked_down(LOCKDOWN_TRACEFS)) { + if (security_locked_down(current_cred(), LOCKDOWN_TRACEFS)) { pr_warn("Can not set tracing clock due to lockdown\n"); return; } diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 830b3b9940f4..c1e4f7f93c0e 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2130,7 +2130,7 @@ ftrace_event_open(struct inode *inode, struct file *file, struct seq_file *m; int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index a6061a69aa84..e122f0467421 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -4917,7 +4917,7 @@ static int event_hist_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; @@ -5189,7 +5189,7 @@ static int event_hist_debug_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index d54094b7a9d7..deac45f00f3a 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -2174,7 +2174,7 @@ static int synth_events_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index 3d5c07239a2a..38226c386f82 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -190,7 +190,7 @@ static int event_trigger_regex_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 3a64ba4bbad6..9178ad52290e 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -479,7 +479,7 @@ static int __register_trace_kprobe(struct trace_kprobe *tk) { int i, ret; - ret = security_locked_down(LOCKDOWN_KPROBES); + ret = security_locked_down(current_cred(), LOCKDOWN_KPROBES); if (ret) return ret; @@ -1141,7 +1141,7 @@ static int probes_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; @@ -1199,7 +1199,7 @@ static int profile_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 4b320fe7df70..47c808484cb2 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -362,7 +362,7 @@ ftrace_formats_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 63c285042051..63b6ebe7bdce 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -477,7 +477,7 @@ static int stack_trace_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_stat.c b/kernel/trace/trace_stat.c index 8d141c3825a9..2f6ae81ee67e 100644 --- a/kernel/trace/trace_stat.c +++ b/kernel/trace/trace_stat.c @@ -236,7 +236,7 @@ static int tracing_stat_open(struct inode *inode, struct file *file) struct seq_file *m; struct stat_session *session = inode->i_private; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 225ce569bf8f..4b114e4fe436 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -781,7 +781,7 @@ static int probes_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; @@ -836,7 +836,7 @@ static int profile_open(struct inode *inode, struct file *file) { int ret; - ret = security_locked_down(LOCKDOWN_TRACEFS); + ret = security_locked_down(current_cred(), LOCKDOWN_TRACEFS); if (ret) return ret; diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 03b66d154b2b..ffd560514d8f 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -850,8 +850,15 @@ static int copy_user_offload(struct xfrm_state_offload *xso, struct sk_buff *skb static bool xfrm_redact(void) { - return IS_ENABLED(CONFIG_SECURITY) && - security_locked_down(LOCKDOWN_XFRM_SECRET); + /* Don't use current_cred() here, since this may be called when + * broadcasting a notification that an SA has been created/deleted. + * In that case current task is the one triggering the notification, + * but the SA key is actually leaked to the event subscribers. + * Since we can't easily do the redact decision per-subscriber, + * just pass NULL here, indicating to the LSMs that a global lockdown + * decision should be made instead. + */ + return security_locked_down(NULL, LOCKDOWN_XFRM_SECRET); } static int copy_to_user_auth(struct xfrm_algo_auth *auth, struct sk_buff *skb) diff --git a/security/lockdown/lockdown.c b/security/lockdown/lockdown.c index 87cbdc64d272..2abe92157e82 100644 --- a/security/lockdown/lockdown.c +++ b/security/lockdown/lockdown.c @@ -55,7 +55,8 @@ early_param("lockdown", lockdown_param); * lockdown_is_locked_down - Find out if the kernel is locked down * @what: Tag to use in notice generated if lockdown is in effect */ -static int lockdown_is_locked_down(enum lockdown_reason what) +static int lockdown_is_locked_down(const struct cred *cred, + enum lockdown_reason what) { if (WARN(what >= LOCKDOWN_CONFIDENTIALITY_MAX, "Invalid lockdown reason")) diff --git a/security/security.c b/security/security.c index 9ffa9e9c5c55..51245e37b351 100644 --- a/security/security.c +++ b/security/security.c @@ -2593,9 +2593,9 @@ void security_bpf_prog_free(struct bpf_prog_aux *aux) } #endif /* CONFIG_BPF_SYSCALL */ -int security_locked_down(enum lockdown_reason what) +int security_locked_down(const struct cred *cred, enum lockdown_reason what) { - return call_int_hook(locked_down, 0, what); + return call_int_hook(locked_down, 0, cred, what); } EXPORT_SYMBOL(security_locked_down); diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 6517f221d52c..300bc9e1ffbf 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -7013,10 +7013,10 @@ static void selinux_bpf_prog_free(struct bpf_prog_aux *aux) } #endif -static int selinux_lockdown(enum lockdown_reason what) +static int selinux_lockdown(const struct cred *cred, enum lockdown_reason what) { struct common_audit_data ad; - u32 sid = current_sid(); + u32 sid; int invalid_reason = (what <= LOCKDOWN_NONE) || (what == LOCKDOWN_INTEGRITY_MAX) || (what >= LOCKDOWN_CONFIDENTIALITY_MAX); @@ -7028,6 +7028,9 @@ static int selinux_lockdown(enum lockdown_reason what) return -EINVAL; } + /* Use SECINITSID_KERNEL if there is no relevant cred to check against */ + sid = cred ? cred_sid(cred) : SECINITSID_KERNEL; + ad.type = LSM_AUDIT_DATA_LOCKDOWN; ad.u.reason = what;