| Message ID | 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-lio_main-c-v1-1-663e3f1d8f99@google.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 092b0be650325b3db490b48182ae23dba0b5755c |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: liquidio: replace deprecated strncpy with strscpy_pad | expand |
On Thu, Oct 05, 2023 at 09:41:01PM +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 know `fw_type` must be NUL-terminated based on use here: > | static bool fw_type_is_auto(void) > | { > | return strncmp(fw_type, LIO_FW_NAME_TYPE_AUTO, > | sizeof(LIO_FW_NAME_TYPE_AUTO)) == 0; > | } > ...and here > | module_param_string(fw_type, fw_type, sizeof(fw_type), 0444); > > Let's opt to NUL-pad the destination buffer as well so that we maintain > the same exact behavior that `strncpy` provided here. > > A suitable replacement is `strscpy_pad` due to the fact that it > guarantees both NUL-termination and NUL-padding on the destination > buffer. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] > Link: https://github.com/KSPP/linux/issues/90 > Cc: linux-hardening@vger.kernel.org > Signed-off-by: Justin Stitt <justinstitt@google.com> Looks like a safe replacement with strscpy_pad(). Reviewed-by: Kees Cook <keescook@chromium.org> > --- > Note: build-tested only. > --- > drivers/net/ethernet/cavium/liquidio/lio_main.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c > index 100daadbea2a..34f02a8ec2ca 100644 > --- a/drivers/net/ethernet/cavium/liquidio/lio_main.c > +++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c > @@ -1689,7 +1689,7 @@ static int load_firmware(struct octeon_device *oct) > > if (fw_type_is_auto()) { > tmp_fw_type = LIO_FW_NAME_TYPE_NIC; > - strncpy(fw_type, tmp_fw_type, sizeof(fw_type)); > + strscpy_pad(fw_type, tmp_fw_type, sizeof(fw_type)); > } else { > tmp_fw_type = fw_type; > } > > --- > base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 > change-id: 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-lio_main-c-b05f78661635 > > Best regards, > -- > Justin Stitt <justinstitt@google.com> > >
Hello: This patch was applied to netdev/net-next.git (main) by Jakub Kicinski <kuba@kernel.org>: On Thu, 05 Oct 2023 21:41:01 +0000 you 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 know `fw_type` must be NUL-terminated based on use here: > | static bool fw_type_is_auto(void) > | { > | return strncmp(fw_type, LIO_FW_NAME_TYPE_AUTO, > | sizeof(LIO_FW_NAME_TYPE_AUTO)) == 0; > | } > ...and here > | module_param_string(fw_type, fw_type, sizeof(fw_type), 0444); > > [...] Here is the summary with links: - net: liquidio: replace deprecated strncpy with strscpy_pad https://git.kernel.org/netdev/net-next/c/092b0be65032 You are awesome, thank you!
diff --git a/drivers/net/ethernet/cavium/liquidio/lio_main.c b/drivers/net/ethernet/cavium/liquidio/lio_main.c index 100daadbea2a..34f02a8ec2ca 100644 --- a/drivers/net/ethernet/cavium/liquidio/lio_main.c +++ b/drivers/net/ethernet/cavium/liquidio/lio_main.c @@ -1689,7 +1689,7 @@ static int load_firmware(struct octeon_device *oct) if (fw_type_is_auto()) { tmp_fw_type = LIO_FW_NAME_TYPE_NIC; - strncpy(fw_type, tmp_fw_type, sizeof(fw_type)); + strscpy_pad(fw_type, tmp_fw_type, sizeof(fw_type)); } else { tmp_fw_type = fw_type; }
`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 know `fw_type` must be NUL-terminated based on use here: | static bool fw_type_is_auto(void) | { | return strncmp(fw_type, LIO_FW_NAME_TYPE_AUTO, | sizeof(LIO_FW_NAME_TYPE_AUTO)) == 0; | } ...and here | module_param_string(fw_type, fw_type, sizeof(fw_type), 0444); Let's opt to NUL-pad the destination buffer as well so that we maintain the same exact behavior that `strncpy` provided here. A suitable replacement is `strscpy_pad` due to the fact that it guarantees both NUL-termination and NUL-padding on the destination buffer. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] 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. --- drivers/net/ethernet/cavium/liquidio/lio_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2 change-id: 20231005-strncpy-drivers-net-ethernet-cavium-liquidio-lio_main-c-b05f78661635 Best regards, -- Justin Stitt <justinstitt@google.com>