| Message ID | 20231003-strncpy-drivers-message-fusion-mptsas-c-v2-1-5ce07e60bd21@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] scsi: message: fusion: replace deprecated strncpy with strscpy | expand |
On Tue, Oct 03, 2023 at 10:15:45PM +0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > The only caller of mptsas_exp_repmanufacture_info() is > mptsas_probe_one_phy() which can allocate rphy in either > sas_end_device_alloc() or sas_expander_alloc(). Both of which > zero-allocate: > | rdev = kzalloc(sizeof(*rdev), GFP_KERNEL); > ... this is supplied to mptsas_exp_repmanufacture_info() as edev meaning > that no future NUL-padding of edev members is needed. > > Considering the above, a suitable replacement is `strscpy` [2] due to > the fact that it guarantees NUL-termination on the destination buffer > without unnecessarily NUL-padding. > > Also use the more idiomatic strscpy pattern of (dest, src, sizeof(dest)) > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Cc: Kees Cook <keescook@chromium.org> > Signed-off-by: Justin Stitt <justinstitt@google.com> Thanks for adjusting the sizes. Looks good! Reviewed-by: Kees Cook <keescook@chromium.org>
Justin, > `strncpy` is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. Applied to 6.7/scsi-staging, thanks!
On Tue, 03 Oct 2023 22:15:45 +0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings > [1] and as such we should prefer more robust and less ambiguous string > interfaces. > > The only caller of mptsas_exp_repmanufacture_info() is > mptsas_probe_one_phy() which can allocate rphy in either > sas_end_device_alloc() or sas_expander_alloc(). Both of which > zero-allocate: > | rdev = kzalloc(sizeof(*rdev), GFP_KERNEL); > ... this is supplied to mptsas_exp_repmanufacture_info() as edev meaning > that no future NUL-padding of edev members is needed. > > [...] Applied to 6.7/scsi-queue, thanks! [1/1] scsi: message: fusion: replace deprecated strncpy with strscpy https://git.kernel.org/mkp/scsi/c/45e833f0e5bb
diff --git a/drivers/message/fusion/mptsas.c b/drivers/message/fusion/mptsas.c index 86f16f3ea478..300f8e955a53 100644 --- a/drivers/message/fusion/mptsas.c +++ b/drivers/message/fusion/mptsas.c @@ -2964,17 +2964,17 @@ mptsas_exp_repmanufacture_info(MPT_ADAPTER *ioc, goto out_free; manufacture_reply = data_out + sizeof(struct rep_manu_request); - strncpy(edev->vendor_id, manufacture_reply->vendor_id, - SAS_EXPANDER_VENDOR_ID_LEN); - strncpy(edev->product_id, manufacture_reply->product_id, - SAS_EXPANDER_PRODUCT_ID_LEN); - strncpy(edev->product_rev, manufacture_reply->product_rev, - SAS_EXPANDER_PRODUCT_REV_LEN); + strscpy(edev->vendor_id, manufacture_reply->vendor_id, + sizeof(edev->vendor_id)); + strscpy(edev->product_id, manufacture_reply->product_id, + sizeof(edev->product_id)); + strscpy(edev->product_rev, manufacture_reply->product_rev, + sizeof(edev->product_rev)); edev->level = manufacture_reply->sas_format; if (manufacture_reply->sas_format) { - strncpy(edev->component_vendor_id, + strscpy(edev->component_vendor_id, manufacture_reply->component_vendor_id, - SAS_EXPANDER_COMPONENT_VENDOR_ID_LEN); + sizeof(edev->component_vendor_id)); tmp = (u8 *)&manufacture_reply->component_id; edev->component_id = tmp[0] << 8 | tmp[1]; edev->component_revision_id =
`strncpy` is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. The only caller of mptsas_exp_repmanufacture_info() is mptsas_probe_one_phy() which can allocate rphy in either sas_end_device_alloc() or sas_expander_alloc(). Both of which zero-allocate: | rdev = kzalloc(sizeof(*rdev), GFP_KERNEL); ... this is supplied to mptsas_exp_repmanufacture_info() as edev meaning that no future NUL-padding of edev members is needed. Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Also use the more idiomatic strscpy pattern of (dest, src, sizeof(dest)) Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Justin Stitt <justinstitt@google.com> --- Changes in v2: - use sizeof(dest) pattern (thanks Kees) - rebase onto mainline cbf3a2cb156a2c91 - Link to v1: https://lore.kernel.org/r/20230927-strncpy-drivers-message-fusion-mptsas-c-v1-1-edac65cd7010@google.com --- Note: build-tested only. Note: similar to drivers/scsi/mpi3mr/mpi3mr_transport.c +212 which uses strscpy --- drivers/message/fusion/mptsas.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20230927-strncpy-drivers-message-fusion-mptsas-c-f22d5a4082e2 Best regards, -- Justin Stitt <justinstitt@google.com>