Commit a8bb681e authored Aug 13, 2025 by Dmitry Antipov Committed by Greg Kroah-Hartman Sep 09, 2025

wifi: cfg80211: fix use-after-free in cmp_bss()



[ Upstream commit 26e84445f02ce6b2fe5f3e0e28ff7add77f35e08 ]

Following bss_free() quirk introduced in commit 776b3580
("cfg80211: track hidden SSID networks properly"), adjust
cfg80211_update_known_bss() to free the last beacon frame
elements only if they're not shared via the corresponding
'hidden_beacon_bss' pointer.

Reported-by:  <syzbot+30754ca335e6fb7e3092@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=30754ca335e6fb7e3092


Fixes: 3ab8227d ("cfg80211: refactor cfg80211_bss_update")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://patch.msgid.link/20250813135236.799384-1-dmantipov@yandex.ru


Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent f84794ad

net/wireless/scan.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1219,6 +1219,7 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
		*/

		f = rcu_access_pointer(new->pub.beacon_ies);
		if (!new->pub.hidden_beacon_bss)
		kfree_rcu((struct cfg80211_bss_ies *)f, rcu_head);
		return false;
		}