| Message ID | 20230824-strncpy-drivers-accel-ivpu-ivpu_jsm_msg-c-v1-1-12d9b52d2dff@google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | accel/ivpu: refactor deprecated strncpy | expand |
On Thu, Aug 24, 2023 at 09:20:25PM +0000, Justin Stitt wrote: > `strncpy` is deprecated for use on NUL-terminated destination strings [1]. > > A suitable replacement is `strscpy` [2] due to the fact that it > guarantees NUL-termination on its destination buffer argument which is > _not_ the case for `strncpy`! > > Also remove extraneous if-statement as it can never be entered. The > return value from `strncpy` is it's first argument. In this case, > `...dyndbg_cmd` is an array: > | char dyndbg_cmd[VPU_DYNDBG_CMD_MAX_LEN]; > ^^^^^^^^^^ > This can never be NULL which means `strncpy`'s return value cannot be > NULL here. Just use `strscpy` which is more robust and results in > simpler and less ambiguous code. > > Moreover, remove needless `... - 1` as `strscpy`'s implementation > ensures NUL-termination and we do not need to carefully dance around > ending boundaries with a "- 1" anymore. > > Link: 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> Applied to drm-misc-next-fixes Thanks Stanislaw
diff --git a/drivers/accel/ivpu/ivpu_jsm_msg.c b/drivers/accel/ivpu/ivpu_jsm_msg.c index 831bfd2b2d39..bdddef2c59ee 100644 --- a/drivers/accel/ivpu/ivpu_jsm_msg.c +++ b/drivers/accel/ivpu/ivpu_jsm_msg.c @@ -118,8 +118,7 @@ int ivpu_jsm_dyndbg_control(struct ivpu_device *vdev, char *command, size_t size struct vpu_jsm_msg resp; int ret; - if (!strncpy(req.payload.dyndbg_control.dyndbg_cmd, command, VPU_DYNDBG_CMD_MAX_LEN - 1)) - return -ENOMEM; + strscpy(req.payload.dyndbg_control.dyndbg_cmd, command, VPU_DYNDBG_CMD_MAX_LEN); ret = ivpu_ipc_send_receive(vdev, &req, VPU_JSM_MSG_DYNDBG_CONTROL_RSP, &resp, VPU_IPC_CHAN_ASYNC_CMD, vdev->timeout.jsm);
`strncpy` is deprecated for use on NUL-terminated destination strings [1]. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on its destination buffer argument which is _not_ the case for `strncpy`! Also remove extraneous if-statement as it can never be entered. The return value from `strncpy` is it's first argument. In this case, `...dyndbg_cmd` is an array: | char dyndbg_cmd[VPU_DYNDBG_CMD_MAX_LEN]; ^^^^^^^^^^ This can never be NULL which means `strncpy`'s return value cannot be NULL here. Just use `strscpy` which is more robust and results in simpler and less ambiguous code. Moreover, remove needless `... - 1` as `strscpy`'s implementation ensures NUL-termination and we do not need to carefully dance around ending boundaries with a "- 1" anymore. Link: 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. --- drivers/accel/ivpu/ivpu_jsm_msg.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- base-commit: f9604036a3fb6149badf346994b46b03f9292db7 change-id: 20230824-strncpy-drivers-accel-ivpu-ivpu_jsm_msg-c-2422f7f00fc8 Best regards, -- Justin Stitt <justinstitt@google.com>