wifi: cfg80211: replace 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().

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>
Link: https://lore.kernel.org/r/20230612232301.2572316-1-azeemshaikh38@gmail.com
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

diff --git a/net/wireless/trace.h b/net/wireless/trace.h
index 716a1fa..a00da3e 100644 (file)
--- 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