2023-05-22 15:56:09

by Azeem Shaikh

Subject: [PATCH] drm/i915: Replace all non-returning strlcpy with strscpy

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 <[email protected]>
---
drivers/gpu/drm/i915/selftests/i915_perf.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/selftests/i915_perf.c b/drivers/gpu/drm/i915/selftests/i915_perf.c
index 24dde5531423..d4608b220123 100644
--- a/drivers/gpu/drm/i915/selftests/i915_perf.c
+++ b/drivers/gpu/drm/i915/selftests/i915_perf.c
@@ -28,7 +28,7 @@ alloc_empty_config(struct i915_perf *perf)
oa_config->perf = perf;
kref_init(&oa_config->ref);

- strlcpy(oa_config->uuid, TEST_OA_CONFIG_UUID, sizeof(oa_config->uuid));
+ strscpy(oa_config->uuid, TEST_OA_CONFIG_UUID, sizeof(oa_config->uuid));

mutex_lock(&perf->metrics_lock);

2023-05-22 20:29:38

by Kees Cook

Subject: Re: [PATCH] drm/i915: Replace all non-returning strlcpy with strscpy

On Mon, May 22, 2023 at 03:52:28PM +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 <[email protected]>

Reviewed-by: Kees Cook <[email protected]>

--
Kees Cook

2023-05-24 14:13:15

by Rodrigo Vivi

Subject: Re: [PATCH] drm/i915: Replace all non-returning strlcpy with strscpy

On Mon, May 22, 2023 at 01:16:03PM -0700, Kees Cook wrote:
> On Mon, May 22, 2023 at 03:52:28PM +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 <[email protected]>
>
> Reviewed-by: Kees Cook <[email protected]>

pushed to drm-intel-next. Thanks for the patch and review.

>
> --
> Kees Cook