Re: [syzbot] [mptcp?] KASAN: slab-use-after-free Read in __timer_delete_sync

[Edward Adam Davis]

entry need to be protected by pm.lock.

#syz test

Upstream-Status: Pending

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 3e4ad801786f..d4cbf7dcf983 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1430,8 +1430,10 @@ static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
 
 	entry = mptcp_pm_del_add_timer(msk, addr, false);
 	if (entry) {
+		spin_lock_bh(&msk->pm.lock);
 		list_del(&entry->list);
 		kfree(entry);
+		spin_unlock_bh(&msk->pm.lock);
 		return true;
 	}