Commit 3b9bc84d authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

net: tun: unlink NAPI from device on destruction 



Syzbot found a race between tun file and device destruction.
NAPIs live in struct tun_file which can get destroyed before
the netdev so we have to del them explicitly. The current
code is missing deleting the NAPI if the queue was detached
first.

Fixes: 94317099 ("tun: enable NAPI for TUN/TAP driver")
Reported-by: default avatar <syzbot+b75c138e9286ac742647@syzkaller.appspotmail.com>
Link: https://lore.kernel.org/r/20220623042039.2274708-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 6f0012e3

drivers/net/tun.c

+1 −0
Original line number Diff line number Diff line
@@ -727,6 +727,7 @@ static void tun_detach_all(struct net_device *dev) 
		sock_put(&tfile->sk);

	}

	list_for_each_entry_safe(tfile, tmp, &tun->disabled, next) {

		tun_napi_del(tfile);

		tun_enable_queue(tfile);

		tun_queue_purge(tfile);

		xdp_rxq_info_unreg(&tfile->xdp_rxq);