[PATCH] cfg80211: cfg80211: strlcpy withreturn

[PATCH] cfg80211: cfg80211: strlcpy withreturn

[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().

Direct replacement is safe here since WIPHY_ASSIGN is only used by
TRACE macros and the return values are ignored.

[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>
---
 net/wireless/trace.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 716a1fa70069..a00da3ebfed5 100644
--- a/net/wireless/trace.h
+++ b/net/wireless/trace.h
@@ -22,7 +22,7 @@
 
 #define MAXNAME		32
 #define WIPHY_ENTRY	__array(char, wiphy_name, 32)
-#define WIPHY_ASSIGN	strlcpy(__entry->wiphy_name, wiphy_name(wiphy), MAXNAME)
+#define WIPHY_ASSIGN	strscpy(__entry->wiphy_name, wiphy_name(wiphy), MAXNAME)
 #define WIPHY_PR_FMT	"%s"
 #define WIPHY_PR_ARG	__entry->wiphy_name
 
-- 
2.41.0.162.gfafddb0af9-goog

Re: [PATCH] cfg80211: cfg80211: strlcpy withreturn

[Kees Cook]

On Mon, Jun 12, 2023 at 11:23:01PM +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().
> 
> Direct replacement is safe here since WIPHY_ASSIGN is only used by
> TRACE macros and the return values are ignored.
> 
> [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] cfg80211: cfg80211: strlcpy withreturn

[Kalle Valo]

Azeem Shaikh <azeemshaikh38@gmail.com> writes:

> 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().
>
> Direct replacement is safe here since WIPHY_ASSIGN is only used by
> TRACE macros and the return values are ignored.
>
> [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>

The title should be:

wifi: cfg80211: replace strlcpy() with strlscpy()

-- 
https://patchwork.kernel.org/project/linux-wireless/list/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches

Re: [PATCH] cfg80211: cfg80211: strlcpy withreturn

[Azeem Shaikh]

On Wed, Jun 14, 2023 at 3:40 AM Kalle Valo <kvalo@kernel.org> wrote:
>
> Azeem Shaikh <azeemshaikh38@gmail.com> writes:
>
> > 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().
> >
> > Direct replacement is safe here since WIPHY_ASSIGN is only used by
> > TRACE macros and the return values are ignored.
> >
> > [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>
>
> The title should be:
>
> wifi: cfg80211: replace strlcpy() with strlscpy()
>

Ack. Sent out a v2.

> --
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>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches