From: Jakub Kicinski kuba@kernel.org
commit 3b9bc84d311104906d2b4995a9a02d7b7ddab2db upstream.
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: 943170998b20 ("tun: enable NAPI for TUN/TAP driver") Reported-by: syzbot+b75c138e9286ac742647@syzkaller.appspotmail.com Link: https://lore.kernel.org/r/20220623042039.2274708-1-kuba@kernel.org Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -728,6 +728,7 @@ static void tun_detach_all(struct net_de 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);