From d5c7c745f254c6cb98b3b3f15fe789b8bd770c72 Mon Sep 17 00:00:00 2001 From: Cong Wang Date: Sat, 29 Dec 2018 13:56:37 -0800 Subject: [PATCH] net/wan: fix a double free in x25_asy_open_tty() When x25_asy_open() fails, it already cleans up by itself, so its caller doesn't need to free the memory again. It seems we still have to call x25_asy_free() to clear the SLF_INUSE bit, so just set these pointers to NULL after kfree(). Reported-and-tested-by: syzbot+5e5e969e525129229052@syzkaller.appspotmail.com Fixes: 3b780bed3138 ("x25_asy: Free x25_asy on x25_asy_open() failure.") Signed-off-by: Cong Wang Signed-off-by: David S. Miller --- drivers/net/wan/x25_asy.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/net/wan/x25_asy.c b/drivers/net/wan/x25_asy.c index 1098263ab862..46c3d983b7b7 100644 --- a/drivers/net/wan/x25_asy.c +++ b/drivers/net/wan/x25_asy.c @@ -485,8 +485,10 @@ static int x25_asy_open(struct net_device *dev) /* Cleanup */ kfree(sl->xbuff); + sl->xbuff = NULL; noxbuff: kfree(sl->rbuff); + sl->rbuff = NULL; norbuff: return -ENOMEM; }