From: Hillf Danton <hdanton@sina.com>
To: syzbot <syzbot+03450dacbc626061c3a3@syzkaller.appspotmail.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] KASAN: use-after-free Read in l2cap_conn_del
Date: Sun, 23 Oct 2022 16:29:48 +0800 [thread overview]
Message-ID: <20221023082948.2403-1-hdanton@sina.com> (raw)
In-Reply-To: <000000000000fa882f05e9973a36@google.com>
On 26 Sep 2022 09:43:42 -0700
> syzbot found the following issue on:
>
> HEAD commit: aaa11ce2ffc8 Add linux-next specific files for 20220923
> git tree: linux-next
> console+strace: https://syzkaller.appspot.com/x/log.txt?x=14b32754880000
> kernel config: https://syzkaller.appspot.com/x/.config?x=186d1ff305f10294
> dashboard link: https://syzkaller.appspot.com/bug?extid=03450dacbc626061c3a3
> compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12d389c4880000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14269e38880000
Put refcount in balance for channel in bid to fix uaf.
#syz test https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git aaa11ce2ffc8
--- a/net/bluetooth/a2mp.c
+++ b/net/bluetooth/a2mp.c
@@ -896,6 +896,8 @@ struct l2cap_chan *a2mp_channel_create(s
BT_ERR("Could not create AMP manager");
return NULL;
}
+ /* pair with put in l2cap_data_channel() */
+ l2cap_chan_hold(mgr->a2mp_chan);
BT_DBG("mgr: %p chan %p", mgr, mgr->a2mp_chan);
--
next prev parent reply other threads:[~2022-10-23 8:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-26 16:43 [syzbot] KASAN: use-after-free Read in l2cap_conn_del syzbot
2022-10-23 8:29 ` Hillf Danton [this message]
2022-10-23 15:43 ` syzbot
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