On Sun, Apr 26, 2020 at 1:52 PM Jason A. Donenfeld <Jason@xxxxxxxxx> wrote: > > It looks like part of the issue might be that I call > udp_tunnel6_xmit_skb while holding rcu_read_lock_bh, in > drivers/net/wireguard/socket.c. But I think there's good reason to do > so, and udp_tunnel6_xmit_skb should be rcu safe. In fact, > every.single.other user of udp_tunnel6_xmit_skb in the kernel uses it > with rcu locked. So, hm... In the syzkaller log, it looks like several runs are hitting: run #0: crashed: INFO: rcu detected stall in netlink_sendmsg And other runs are hitting yet different functions. So actually, it's not clear that this is the fault of the call to udp_tunnel6_xmit_skb.
