From c7256f579f8302ce2c038181c30060d0b40017b2 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 28 Sep 2018 14:51:48 -0700 Subject: tun: initialize napi_mutex unconditionally This is the first part to fix following syzbot report : console output: https://syzkaller.appspot.com/x/log.txt?x=145378e6400000 kernel config: https://syzkaller.appspot.com/x/.config?x=443816db871edd66 dashboard link: https://syzkaller.appspot.com/bug?extid=e662df0ac1d753b57e80 Following patch is fixing the race condition, but it seems safer to initialize this mutex at tfile creation anyway. Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Eric Dumazet Reported-by: syzbot+e662df0ac1d753b57e80@syzkaller.appspotmail.com Signed-off-by: David S. Miller --- drivers/net/tun.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net/tun.c') diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 71d10fb59849..729686babbf3 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -320,7 +320,6 @@ static void tun_napi_init(struct tun_struct *tun, struct tun_file *tfile, netif_napi_add(tun->dev, &tfile->napi, tun_napi_poll, NAPI_POLL_WEIGHT); napi_enable(&tfile->napi); - mutex_init(&tfile->napi_mutex); } } @@ -3199,6 +3198,7 @@ static int tun_chr_open(struct inode *inode, struct file * file) return -ENOMEM; } + mutex_init(&tfile->napi_mutex); RCU_INIT_POINTER(tfile->tun, NULL); tfile->flags = 0; tfile->ifindex = 0; -- cgit v1.2.3-59-g8ed1b