| Message ID | 20240830132303.6665-1-gourry@gourry.net |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] tpm: fix signed/unsigned bug when checking event logs | expand |
On 30/08/2024 09:23, Gregory Price wrote: > tpm code currently ignores a relevant failure case silently. > Add an error to make this failure non-silent. > > Signed-off-by: Gregory Price <gourry@gourry.net> > --- > drivers/firmware/efi/tpm.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c > index 9c3613e6af15..b6939a6d44d9 100644 > --- a/drivers/firmware/efi/tpm.c > +++ b/drivers/firmware/efi/tpm.c > @@ -61,7 +61,11 @@ int __init efi_tpm_eventlog_init(void) > } > > tbl_size = sizeof(*log_tbl) + log_tbl->size; > - memblock_reserve(efi.tpm_log, tbl_size); > + if (memblock_reserve(efi.tpm_log, tbl_size)) { > + pr_err("TPM Event Log memblock reserve fails 0x%lx - %x\n", > + efi.tpm_log, tbl_size); > + goto out; > + } > > if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) { > pr_info("TPM Final Events table not present\n"); This was not a proper fix for the issue, sent a bit quickly! I have sent it here https://lore.kernel.org/all/20240830212852.2794145-1-usamaarif642@gmail.com/
On Fri, Aug 30, 2024 at 10:33:22PM +0100, Usama Arif wrote: > > > On 30/08/2024 09:23, Gregory Price wrote: > > tpm code currently ignores a relevant failure case silently. > > Add an error to make this failure non-silent. > > > > Signed-off-by: Gregory Price <gourry@gourry.net> > > --- > > drivers/firmware/efi/tpm.c | 6 +++++- > > 1 file changed, 5 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c > > index 9c3613e6af15..b6939a6d44d9 100644 > > --- a/drivers/firmware/efi/tpm.c > > +++ b/drivers/firmware/efi/tpm.c > > @@ -61,7 +61,11 @@ int __init efi_tpm_eventlog_init(void) > > } > > > > tbl_size = sizeof(*log_tbl) + log_tbl->size; > > - memblock_reserve(efi.tpm_log, tbl_size); > > + if (memblock_reserve(efi.tpm_log, tbl_size)) { > > + pr_err("TPM Event Log memblock reserve fails 0x%lx - %x\n", > > + efi.tpm_log, tbl_size); > > + goto out; > > + } > > > > if (efi.tpm_final_log == EFI_INVALID_TABLE_ADDR) { > > pr_info("TPM Final Events table not present\n"); > > This was not a proper fix for the issue, sent a bit quickly! > > I have sent it here https://lore.kernel.org/all/20240830212852.2794145-1-usamaarif642@gmail.com/ > This change addresses a separately, discrete issue and the two changes should be different patches (this is aside from the change you posted being incorrect for v1_2). ~Gregory
diff --git a/drivers/firmware/efi/tpm.c b/drivers/firmware/efi/tpm.c index e8d69bd548f3..9c3613e6af15 100644 --- a/drivers/firmware/efi/tpm.c +++ b/drivers/firmware/efi/tpm.c @@ -40,7 +40,8 @@ int __init efi_tpm_eventlog_init(void) { struct linux_efi_tpm_eventlog *log_tbl; struct efi_tcg2_final_events_table *final_tbl; - int tbl_size; + unsigned int tbl_size; + int final_tbl_size; int ret = 0; if (efi.tpm_log == EFI_INVALID_TABLE_ADDR) { @@ -80,26 +81,26 @@ int __init efi_tpm_eventlog_init(void) goto out; } - tbl_size = 0; + final_tbl_size = 0; if (final_tbl->nr_events != 0) { void *events = (void *)efi.tpm_final_log + sizeof(final_tbl->version) + sizeof(final_tbl->nr_events); - tbl_size = tpm2_calc_event_log_size(events, - final_tbl->nr_events, - log_tbl->log); + final_tbl_size = tpm2_calc_event_log_size(events, + final_tbl->nr_events, + log_tbl->log); } - if (tbl_size < 0) { + if (final_tbl_size < 0) { pr_err(FW_BUG "Failed to parse event in TPM Final Events Log\n"); ret = -EINVAL; goto out_calc; } memblock_reserve(efi.tpm_final_log, - tbl_size + sizeof(*final_tbl)); - efi_tpm_final_log_size = tbl_size; + final_tbl_size + sizeof(*final_tbl)); + efi_tpm_final_log_size = final_tbl_size; out_calc: early_memunmap(final_tbl, sizeof(*final_tbl));
A prior bugfix that fixes a signed/unsigned error causes another signed unsigned error. A situation where log_tbl->size is invalid can cause the size passed to memblock_reserve to become negative. log_size from the main event log is an unsigned int, and the code reduces to the following u64 value = (int)unsigned_value; This results in sign extension, and the value sent to memblock_reserve becomes effectively negative. Fixes: be59d57f9806 ("efi/tpm: Fix sanity check of unsigned tbl_size being less than zero") Signed-off-by: Gregory Price <gourry@gourry.net> --- drivers/firmware/efi/tpm.c | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-)