2023-06-14 13:47:44

by Azeem Shaikh

Subject: [PATCH v2] wifi: cfg80211: replace strlcpy() with strlscpy()

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 <[email protected]>
---
v1: https://lore.kernel.org/all/[email protected]/

Changes from v1 - updated patch title.

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

2023-06-14 13:48:38

by Azeem Shaikh

Subject: Re: [PATCH v2] wifi: cfg80211: replace strlcpy() with strlscpy()

Please ignore this patch. I made a typo in the title. Resending.

On Wed, Jun 14, 2023 at 9:46 AM Azeem Shaikh <[email protected]> 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 <[email protected]>
> ---
> v1: https://lore.kernel.org/all/[email protected]/
>
> Changes from v1 - updated patch title.
>
> 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
>
>