This is a note to let you know that I've just added the patch titled cfg80211: hold bss_lock while updating nontrans_list to the 5.17-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cfg80211-hold-bss_lock-while-updating-nontrans_list.patch and it can be found in the queue-5.17 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 304f4c81cf51c922e1267063095f7bf784f19591 Author: Rameshkumar Sundaram <quic_ramess@xxxxxxxxxxx> Date: Mon Apr 11 14:37:51 2022 +0530 cfg80211: hold bss_lock while updating nontrans_list [ Upstream commit a5199b5626cd6913cf8776a835bc63d40e0686ad ] Synchronize additions to nontrans_list of transmitting BSS with bss_lock to avoid races. Also when cfg80211_add_nontrans_list() fails __cfg80211_unlink_bss() needs bss_lock to be held (has lockdep assert on bss_lock). So protect the whole block with bss_lock to avoid races and warnings. Found during code review. Fixes: 0b8fb8235be8 ("cfg80211: Parsing of Multiple BSSID information in scanning") Signed-off-by: Rameshkumar Sundaram <quic_ramess@xxxxxxxxxxx> Link: https://lore.kernel.org/r/1649668071-9370-1-git-send-email-quic_ramess@xxxxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/wireless/scan.c b/net/wireless/scan.c index b2fdac96bab0..4a6d86432910 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -2018,11 +2018,13 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy, /* this is a nontransmitting bss, we need to add it to * transmitting bss' list if it is not there */ + spin_lock_bh(&rdev->bss_lock); if (cfg80211_add_nontrans_list(non_tx_data->tx_bss, &res->pub)) { if (__cfg80211_unlink_bss(rdev, res)) rdev->bss_generation++; } + spin_unlock_bh(&rdev->bss_lock); } trace_cfg80211_return_bss(&res->pub);