From c34bde9a354534901f5276769b4019d321632b1c Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 22 Jun 2022 21:20:39 -0700 Subject: [PATCH] net: tun: unlink NAPI from device on destruction BugLink: https://bugs.launchpad.net/bugs/1986728 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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Kamal Mostafa Signed-off-by: Stefan Bader --- drivers/net/tun.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 02de8d998bfa..9cc0e6882900 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -728,6 +728,7 @@ 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); -- 2.39.5