On (01/11/18 21:29), syzbot wrote: > ================================================================== > BUG: KASAN: use-after-free in rds_tcp_tune+0x491/0x520 net/rds/tcp.c:397 > Read of size 4 at addr ffff8801cd5f6c58 by task kworker/u4:4/4954 Just had an offline discussion with santosh around this, here's a summary of that discussion for the archives: Looks like an rds_connect_worker workq got scheduled after the netns was deleted. This could happen if an an rds_connection got added between lines 528 and 529 of 506 static void rds_tcp_kill_sock(struct net *net) : /* code to pull out all the rds_connections that should be destroyed */ : 528 spin_unlock_irq(&rds_tcp_conn_lock); 529 list_for_each_entry_safe(tc, _tc, &tmp_list, t_tcp_node) 530 rds_conn_destroy(tc->t_cpath->cp_conn); Such an rds_connection would miss out the rds_conn_destroy() loop (that cancels all pending work) and (if it was scheduled after netns deletion) could trigger the use-after-free. Evaluating various fixes for this (including using _bh instead of _irq as suggested by santosh), I'll get back with a patch soon. --Sowmini -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
