From: Johannes Berg johannes.berg@intel.com

mainline inclusion from mainline-v5.16-rc7 commit 87a270625a89fc841f1a7e21aae6176543d8385c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I95REH CVE: CVE-2021-47091

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We need to hold the local->mtx to release the channel context, as even encoded by the lockdep_assert_held() there. Fix it.

Cc: stable@vger.kernel.org Fixes: 295b02c4be74 ("mac80211: Add FILS discovery support") Reported-and-tested-by: syzbot+11c342e5e30e9539cabd@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20211220090836.cee3d59a1915.I36bba9b79dc2ff4d57c3c... Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: David S. Miller davem@davemloft.net Conflicts: net/mac80211/cfg.c Signed-off-by: Ziyang Xuan william.xuanziyang@huawei.com --- net/mac80211/cfg.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index 2201923238ed..16998a022818 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -972,10 +972,8 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev, IEEE80211_P2P_OPPPS_ENABLE_BIT;

err = ieee80211_assign_beacon(sdata, &params->beacon, NULL); - if (err < 0) { - ieee80211_vif_release_channel(sdata); - return err; - } + if (err < 0) + goto error; changed |= err;

err = drv_start_ap(sdata->local, sdata); @@ -985,8 +983,7 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev, if (old) kfree_rcu(old, rcu_head); RCU_INIT_POINTER(sdata->u.ap.beacon, NULL); - ieee80211_vif_release_channel(sdata); - return err; + goto error; }

ieee80211_recalc_dtim(local, sdata); @@ -997,6 +994,13 @@ static int ieee80211_start_ap(struct wiphy *wiphy, struct net_device *dev, netif_carrier_on(vlan->dev);

return 0; + +error: + mutex_lock(&local->mtx); + ieee80211_vif_release_channel(sdata); + mutex_unlock(&local->mtx); + + return err; }

static int ieee80211_change_beacon(struct wiphy *wiphy, struct net_device *dev,