From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cong Wang Subject: [Patch net] net/wan: fix a double free in x25_asy_open_tty() Date: Sat, 29 Dec 2018 13:56:37 -0800 Message-ID: <20181229215638.10590-2-xiyou.wangcong@gmail.com> References: <20181229215638.10590-1-xiyou.wangcong@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: Cong Wang To: netdev@vger.kernel.org Return-path: Received: from mail-pg1-f196.google.com ([209.85.215.196]:35594 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727117AbeL2V5A (ORCPT ); Sat, 29 Dec 2018 16:57:00 -0500 Received: by mail-pg1-f196.google.com with SMTP id s198so11398059pgs.2 for ; Sat, 29 Dec 2018 13:57:00 -0800 (PST) In-Reply-To: <20181229215638.10590-1-xiyou.wangcong@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: 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 --- 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; } -- 2.19.2