Thread (7 messages) 7 messages, 3 authors, 2024-04-25

Re: [PATCH] video: fbdev: au1200fb: replace deprecated strncpy with strscpy

From: Kees Cook <hidden>
Date: 2024-03-20 02:44:08
Also in: dri-devel, linux-hardening, lkml

On Mon, Mar 18, 2024 at 11:46:33PM +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.

Let's use the new 2-argument strscpy() which guarantees NUL-termination
on the destination buffer while also simplifying the syntax. Note that
strscpy() will not NUL-pad the destination buffer like strncpy() does.

However, the NUL-padding behavior of strncpy() is not required since
fbdev is already NUL-allocated from au1200fb_drv_probe() ->
frameuffer_alloc(), rendering any additional NUL-padding redundant.
|	p = kzalloc(fb_info_size + size, GFP_KERNEL);

Link: https://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>
Yup, looks correct.

Reviewed-by: Kees Cook <redacted>

-- 
Kees Cook
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