6.1-stable review patch. If anyone has any objections, please let me know.
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From: Johannes Berg johannes.berg@intel.com
commit d5fee261dfd9e17b08b1df8471ac5d5736070917 upstream.
When we free wdev->cqm_config when unregistering, we also need to clear out the pointer since the same wdev/netdev may get re-registered in another network namespace, then destroyed later, running this code again, which results in a double-free.
Reported-by: syzbot+36218cddfd84b5cc263e@syzkaller.appspotmail.com Fixes: 37c20b2effe9 ("wifi: cfg80211: fix cqm_config access race") Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20241022161742.7c34b2037726.I121b9cdb7eb180802eafc9... Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/wireless/core.c | 1 + 1 file changed, 1 insertion(+)
--- a/net/wireless/core.c +++ b/net/wireless/core.c @@ -1230,6 +1230,7 @@ static void _cfg80211_unregister_wdev(st /* deleted from the list, so can't be found from nl80211 any more */ cqm_config = rcu_access_pointer(wdev->cqm_config); kfree_rcu(cqm_config, rcu_head); + RCU_INIT_POINTER(wdev->cqm_config, NULL);
/* * Ensure that all events have been processed and