diff options
| author | Siddh Raman Pant <code@siddh.me> | 2022-08-19 23:03:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-08 12:11:40 +0300 |
| commit | 4abc8c07a065ecf771827bde3c63fbbe4aa0c08b (patch) | |
| tree | 46d10980f872f9520fa0405db68c7708c3de193e /net/mac80211 | |
| parent | dd649b49219a0388cc10fc40e4c2ea681566a780 (diff) | |
| download | linux-4abc8c07a065ecf771827bde3c63fbbe4aa0c08b.tar.xz | |
wifi: mac80211: Fix UAF in ieee80211_scan_rx()
commit 60deb9f10eec5c6a20252ed36238b55d8b614a2c upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/mac80211')
| -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 887f945bb12d..d6afaacaf7ef 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -461,16 +461,19 @@ 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); |