linux-kernel - Re: [syzbot] [can?] WARNING: refcount bug in j1939_session

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <tencent_EF9E7E1BB84BDC1B3825FFBA27BBE0333908@qq.com>
Date: Wed,  7 Aug 2024 16:30:28 +0800
From: Edward Adam Davis <eadavis@...com>
To: syzbot+ad601904231505ad6617@...kaller.appspotmail.com
Cc: linux-kernel@...r.kernel.org,
	syzkaller-bugs@...glegroups.com
Subject: Re: [syzbot] [can?] WARNING: refcount bug in j1939_session_put

Fixes: c9c0ee5f20c5 ("net: skbuff: Skip early return in skb_unref when debugging")

Root cause: In commit c9c0ee5f20c5, There are following rules:
In debug builds (CONFIG_DEBUG_NET set), the reference count is always  decremented, even when it's 1

This rule will cause the reference count to be 0 after calling skc_unref,
which will affect the release of skb.

#syz test: upstream master