| Message ID | 20231023-strncpy-drivers-scsi-bnx2fc-bnx2fc_fcoe-c-v1-1-a3736943cde2@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Headers | show |
| Series | scsi: bnx2fc: replace deprecated strncpy with strscpy | expand |
On Mon, Oct 23, 2023 at 08:12:22PM +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. > > We expect hba->chip_num to be NUL-terminated based on its usage with > format strings: > > snprintf(fc_host_symbolic_name(lport->host), 256, > "%s (QLogic %s) v%s over %s", > BNX2FC_NAME, hba->chip_num, BNX2FC_VERSION, > interface->netdev->name); > > Moreover, NUL-padding is not required as hba is zero-allocated from its > callsite: > > hba = kzalloc(sizeof(*hba), GFP_KERNEL); > > 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. > > Regarding stats_addr->version, I've opted to also use strscpy() instead > of strscpy_pad() as I typically see these XYZ_get_strings() pass > zero-allocated data. I couldn't track all of where > bnx2fc_ulp_get_stats() is used and if required, we could opt for > strscpy_pad(). > > 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 > Signed-off-by: Justin Stitt <justinstitt@google.com> This all looks correct to me. 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 6.8/scsi-staging, thanks!
On Mon, 23 Oct 2023 20:12:22 +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. > > We expect hba->chip_num to be NUL-terminated based on its usage with > format strings: > > [...] Applied to 6.8/scsi-queue, thanks! [1/1] scsi: bnx2fc: replace deprecated strncpy with strscpy https://git.kernel.org/mkp/scsi/c/b04a2eff9e9c
diff --git a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c index 05ddbb9bb7d8..3ebfb09329ad 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_fcoe.c +++ b/drivers/scsi/bnx2fc/bnx2fc_fcoe.c @@ -1737,32 +1737,32 @@ static int bnx2fc_bind_pcidev(struct bnx2fc_hba *hba) switch (pdev->device) { case PCI_DEVICE_ID_NX2_57710: - strncpy(hba->chip_num, "BCM57710", BCM_CHIP_LEN); + strscpy(hba->chip_num, "BCM57710", sizeof(hba->chip_num)); break; case PCI_DEVICE_ID_NX2_57711: - strncpy(hba->chip_num, "BCM57711", BCM_CHIP_LEN); + strscpy(hba->chip_num, "BCM57711", sizeof(hba->chip_num)); break; case PCI_DEVICE_ID_NX2_57712: case PCI_DEVICE_ID_NX2_57712_MF: case PCI_DEVICE_ID_NX2_57712_VF: - strncpy(hba->chip_num, "BCM57712", BCM_CHIP_LEN); + strscpy(hba->chip_num, "BCM57712", sizeof(hba->chip_num)); break; case PCI_DEVICE_ID_NX2_57800: case PCI_DEVICE_ID_NX2_57800_MF: case PCI_DEVICE_ID_NX2_57800_VF: - strncpy(hba->chip_num, "BCM57800", BCM_CHIP_LEN); + strscpy(hba->chip_num, "BCM57800", sizeof(hba->chip_num)); break; case PCI_DEVICE_ID_NX2_57810: case PCI_DEVICE_ID_NX2_57810_MF: case PCI_DEVICE_ID_NX2_57810_VF: - strncpy(hba->chip_num, "BCM57810", BCM_CHIP_LEN); + strscpy(hba->chip_num, "BCM57810", sizeof(hba->chip_num)); break; case PCI_DEVICE_ID_NX2_57840: case PCI_DEVICE_ID_NX2_57840_MF: case PCI_DEVICE_ID_NX2_57840_VF: case PCI_DEVICE_ID_NX2_57840_2_20: case PCI_DEVICE_ID_NX2_57840_4_10: - strncpy(hba->chip_num, "BCM57840", BCM_CHIP_LEN); + strscpy(hba->chip_num, "BCM57840", sizeof(hba->chip_num)); break; default: pr_err(PFX "Unknown device id 0x%x\n", pdev->device); @@ -1800,7 +1800,7 @@ static int bnx2fc_ulp_get_stats(void *handle) if (!stats_addr) return -EINVAL; - strncpy(stats_addr->version, BNX2FC_VERSION, + strscpy(stats_addr->version, BNX2FC_VERSION, sizeof(stats_addr->version)); stats_addr->txq_size = BNX2FC_SQ_WQES_MAX; stats_addr->rxq_size = BNX2FC_CQ_WQES_MAX;
strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. We expect hba->chip_num to be NUL-terminated based on its usage with format strings: snprintf(fc_host_symbolic_name(lport->host), 256, "%s (QLogic %s) v%s over %s", BNX2FC_NAME, hba->chip_num, BNX2FC_VERSION, interface->netdev->name); Moreover, NUL-padding is not required as hba is zero-allocated from its callsite: hba = kzalloc(sizeof(*hba), GFP_KERNEL); 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. Regarding stats_addr->version, I've opted to also use strscpy() instead of strscpy_pad() as I typically see these XYZ_get_strings() pass zero-allocated data. I couldn't track all of where bnx2fc_ulp_get_stats() is used and if required, we could opt for strscpy_pad(). 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 Signed-off-by: Justin Stitt <justinstitt@google.com> --- Note: build-tested only. Found with: $ rg "strncpy\(" --- drivers/scsi/bnx2fc/bnx2fc_fcoe.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) --- base-commit: 9c5d00cb7b6bbc5a7965d9ab7d223b5402d1f02c change-id: 20231023-strncpy-drivers-scsi-bnx2fc-bnx2fc_fcoe-c-f24335846e35 Best regards, -- Justin Stitt <justinstitt@google.com>