2023-05-22 15:56:12

by Azeem Shaikh

[permalink] [raw]
Subject: [PATCH] drm/amd/pm: 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/amd/pm/legacy-dpm/legacy_dpm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c b/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
index d3fe149d8476..81fb4e5dd804 100644
--- a/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
+++ b/drivers/gpu/drm/amd/pm/legacy-dpm/legacy_dpm.c
@@ -794,7 +794,7 @@ void amdgpu_add_thermal_controller(struct amdgpu_device *adev)
struct i2c_board_info info = { };
const char *name = pp_lib_thermal_controller_names[controller->ucType];
info.addr = controller->ucI2cAddress >> 1;
- strlcpy(info.type, name, sizeof(info.type));
+ strscpy(info.type, name, sizeof(info.type));
i2c_new_client_device(&adev->pm.i2c_bus->adapter, &info);
}
} else {



2023-05-22 20:19:31

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] drm/amd/pm: Replace all non-returning strlcpy with strscpy

On Mon, May 22, 2023 at 03:52:45PM +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

2023-05-22 20:47:45

by Deucher, Alexander

[permalink] [raw]
Subject: RE: [PATCH] drm/amd/pm: Replace all non-returning strlcpy with strscpy

[Public]

> -----Original Message-----
> From: Kees Cook <[email protected]>
> Sent: Monday, May 22, 2023 4:16 PM
> To: Azeem Shaikh <[email protected]>
> Cc: Quan, Evan <[email protected]>; [email protected];
> [email protected]; [email protected]; Deucher,
> Alexander <[email protected]>; Koenig, Christian
> <[email protected]>; Pan, Xinhui <[email protected]>; David
> Airlie <[email protected]>; Daniel Vetter <[email protected]>; dri-
> [email protected]
> Subject: Re: [PATCH] drm/amd/pm: Replace all non-returning strlcpy with
> strscpy
>
> On Mon, May 22, 2023 at 03:52:45PM +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]>
>

Acked-by: Alex Deucher <[email protected]>

Ack to take this through whatever tree makes sense if you are trying to batch all of these up. Otherwise, I can pick them up.

Alex

2023-05-22 21:19:39

by Kees Cook

[permalink] [raw]
Subject: Re: [PATCH] drm/amd/pm: Replace all non-returning strlcpy with strscpy

On Mon, 22 May 2023 15:52:45 +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.
>
> [...]

Applied to for-next/hardening, thanks!

[1/1] drm/amd/pm: Replace all non-returning strlcpy with strscpy
https://git.kernel.org/kees/c/0f53b61b1ca0

--
Kees Cook