diff options
| author | Siddh Raman Pant <code@siddh.me> | 2022-08-20 01:33:40 +0530 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2022-08-25 10:00:21 +0200 |
| commit | 60deb9f10eec5c6a20252ed36238b55d8b614a2c (patch) | |
| tree | 9a372137cd50ef90756915e2a8f9543059ccca0c | |
| parent | 24c7a64ea4764d70e4ac9b0a60ecd9b03c68435e (diff) | |
wifi: mac80211: Fix UAF in ieee80211_scan_rx()
ieee80211_scan_rx() tries to access scan_req->flags after a
null check, but a UAF is observed when the scan is completed
and __ieee80211_scan_completed() executes, which then calls
cfg80211_scan_done() leading to the freeing of scan_req.
Since scan_req is rcu_dereference()'d, prevent the racing in
__ieee80211_scan_completed() by ensuring that from mac80211's
POV it is no longer accessed from an RCU read critical section
before we call cfg80211_scan_done().
Cc: stable@vger.kernel.org
Link: https://syzkaller.appspot.com/bug?extid=f9acff9bf08a845f225d
Reported-by: syzbot+f9acff9bf08a845f225d@syzkaller.appspotmail.com
Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Siddh Raman Pant <code@siddh.me>
Link: https://lore.kernel.org/r/20220819200340.34826-1-code@siddh.me
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
| -rw-r--r-- | net/mac80211/scan.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/net/mac80211/scan.c b/net/mac80211/scan.c index fa8ddf576bc1..c4f2aeb31da3 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -469,16 +469,19 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) scan_req = rcu_dereference_protected(local->scan_req, lockdep_is_held(&local->mtx)); - if (scan_req != local->int_scan_req) { - local->scan_info.aborted = aborted; - cfg80211_scan_done(scan_req, &local->scan_info); - } RCU_INIT_POINTER(local->scan_req, NULL); RCU_INIT_POINTER(local->scan_sdata, NULL); local->scanning = 0; local->scan_chandef.chan = NULL; + synchronize_rcu(); + + if (scan_req != local->int_scan_req) { + local->scan_info.aborted = aborted; + cfg80211_scan_done(scan_req, &local->scan_info); + } + /* Set power back to normal operating levels. */ ieee80211_hw_config(local, 0); |