diff options
| author | Siddh Raman Pant <code@siddh.me> | 2022-08-19 23:03:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-28 12:04:01 +0300 |
| commit | 9ad48cbf8b07f10c1e4a7a262b32a9179ae9dd2d (patch) | |
| tree | 08f9a18f841028defbe23f6a501d88c9d3ecd796 | |
| parent | 9a3695bde9c7fa418cda20cc9f7e0407df33d5cd (diff) | |
| download | linux-9ad48cbf8b07f10c1e4a7a262b32a9179ae9dd2d.tar.xz | |
wifi: mac80211: Fix UAF in ieee80211_scan_rx()
[ Upstream commit 60deb9f10eec5c6a20252ed36238b55d8b614a2c ]
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: Sasha Levin <sashal@kernel.org>
| -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 344b2c22e75b..c353162e81ae 100644 --- a/net/mac80211/scan.c +++ b/net/mac80211/scan.c @@ -431,10 +431,6 @@ 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); scan_sdata = rcu_dereference_protected(local->scan_sdata, @@ -444,6 +440,13 @@ static void __ieee80211_scan_completed(struct ieee80211_hw *hw, bool aborted) 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); |