wifi: cfg80211: validate IEs in cfg80211_wext_siwgenie()

The KASAN allocation trace shows that a malformed IE buffer is
stored via SIOCSIWGENIE (cfg80211_wext_siwgenie()) without any
validation. The crash trace shows that a subsequent SIOCSIWESSID
triggers a connection attempt which calls cfg80211_sme_get_conn_ies()
to process the stored IE buffer, causing:

 - An out-of-bounds read in skip_ie() which reads ies[pos+1]
   (the length byte) past the end of the 1-byte buffer.

 - An integer underflow in the memcpy size argument when offs
   returned by ieee80211_ie_split() exceeds ies_len, causing
   unsigned subtraction to wrap to SIZE_MAX and triggering a
   fortify panic.

Fix this by validating the IE buffer in cfg80211_wext_siwgenie()
before storing it.

Reported-by: syzbot+cc867e537e4bd36f69bb@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=cc867e537e4bd36f69bb
Signed-off-by: Deepanshu Kartikey <kartikey406@gmail.com>
Link: https://patch.msgid.link/20260725142028.32560-1-kartikey406@gmail.com
[drop unnecessary ie_len check, update commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

0 files changed, 0 insertions, 0 deletions