[PATCH] dma-buf/sw_sync: Replace all non-returning strlcpy with strscpy

[PATCH] dma-buf/sw_sync: Replace all non-returning strlcpy with strscpy

[Azeem Shaikh]

strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
No return values were used, so direct replacement is safe.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89

Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
 drivers/dma-buf/sw_sync.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma-buf/sw_sync.c b/drivers/dma-buf/sw_sync.c
index 348b3a9170fa..63f0aeb66db6 100644
--- a/drivers/dma-buf/sw_sync.c
+++ b/drivers/dma-buf/sw_sync.c
@@ -85,7 +85,7 @@ static struct sync_timeline *sync_timeline_create(const char *name)
 
 	kref_init(&obj->kref);
 	obj->context = dma_fence_context_alloc(1);
-	strlcpy(obj->name, name, sizeof(obj->name));
+	strscpy(obj->name, name, sizeof(obj->name));
 
 	obj->pt_tree = RB_ROOT;
 	INIT_LIST_HEAD(&obj->pt_list);

Re: [PATCH] dma-buf/sw_sync: Replace all non-returning strlcpy with strscpy

[Kees Cook]

On Tue, May 23, 2023 at 02:19:43AM +0000, Azeem Shaikh wrote:
> strlcpy() reads the entire source buffer first.
> This read may exceed the destination size limit.
> This is both inefficient and can lead to linear read
> overflows if a source string is not NUL-terminated [1].
> In an effort to remove strlcpy() completely [2], replace
> strlcpy() here with strscpy().
> No return values were used, so direct replacement is safe.
> 
> [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> [2] https://github.com/KSPP/linux/issues/89
> 
> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-- 
Kees Cook

Re: [PATCH] dma-buf/sw_sync: Replace all non-returning strlcpy with strscpy

[Sumit Semwal]

Hello Azeem,


On Tue, 23 May 2023 at 22:52, Kees Cook <keescook@chromium.org> wrote:
>
> On Tue, May 23, 2023 at 02:19:43AM +0000, Azeem Shaikh wrote:
> > strlcpy() reads the entire source buffer first.
> > This read may exceed the destination size limit.
> > This is both inefficient and can lead to linear read
> > overflows if a source string is not NUL-terminated [1].
> > In an effort to remove strlcpy() completely [2], replace
> > strlcpy() here with strscpy().
> > No return values were used, so direct replacement is safe.
> >
> > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
> > [2] https://github.com/KSPP/linux/issues/89
Thank you for the patch; I'll queue it up.
> >
> > Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
>
> Reviewed-by: Kees Cook <keescook@chromium.org>
>
> --
> Kees Cook

Best,
Sumit.

-- 
Thanks and regards,

Sumit Semwal (he / him)
Tech Lead - LCG, Vertical Technologies
Linaro.org │ Open source software for ARM SoCs