From: Hillf Danton <hdanton@sina.com>
To: syzbot <syzbot+0e4ebcc970728e056324@syzkaller.appspotmail.com>
Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [bluetooth?] KASAN: wild-memory-access Read in l2cap_connect_cfm
Date: Sat, 13 Sep 2025 12:02:51 +0800 [thread overview]
Message-ID: <20250913040256.6972-1-hdanton@sina.com> (raw)
In-Reply-To: <68c44056.a70a0220.3543fc.0036.GAE@google.com>
> Date: Fri, 12 Sep 2025 08:46:30 -0700 [thread overview]
> syzbot has found a reproducer for the following issue on:
>
> HEAD commit: 590b221ed425 Add linux-next specific files for 20250912
> git tree: linux-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=161d1934580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=9134e501f17b95a4
> dashboard link: https://syzkaller.appspot.com/bug?extid=0e4ebcc970728e056324
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=111d1934580000
#syz test
--- x/include/net/bluetooth/l2cap.h
+++ y/include/net/bluetooth/l2cap.h
@@ -938,6 +938,7 @@ static inline long l2cap_chan_no_get_snd
extern bool disable_ertm;
extern bool enable_ecred;
+extern struct mutex cfm_mutex;
int l2cap_init_sockets(void);
void l2cap_cleanup_sockets(void);
--- x/net/bluetooth/l2cap_sock.c
+++ y/net/bluetooth/l2cap_sock.c
@@ -1411,6 +1411,7 @@ shutdown_already:
return err;
}
+DEFINE_MUTEX(cfm_mutex);
static int l2cap_sock_release(struct socket *sock)
{
struct sock *sk = sock->sk;
@@ -1422,9 +1423,11 @@ static int l2cap_sock_release(struct soc
if (!sk)
return 0;
+ mutex_lock(&cfm_mutex);
lock_sock_nested(sk, L2CAP_NESTING_PARENT);
l2cap_sock_cleanup_listen(sk);
release_sock(sk);
+ mutex_unlock(&cfm_mutex);
bt_sock_unlink(&l2cap_sk_list, sk);
--- x/net/bluetooth/l2cap_core.c
+++ y/net/bluetooth/l2cap_core.c
@@ -7301,7 +7301,9 @@ next:
pchan = next;
}
+ mutex_lock(&cfm_mutex);
l2cap_conn_ready(conn);
+ mutex_unlock(&cfm_mutex);
}
int l2cap_disconn_ind(struct hci_conn *hcon)
--
next prev parent reply other threads:[~2025-09-13 4:08 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-03-17 15:57 [syzbot] [bluetooth?] KASAN: wild-memory-access Read in l2cap_connect_cfm syzbot
2025-09-12 15:46 ` syzbot
2025-09-13 4:02 ` Hillf Danton [this message]
2025-09-13 4:28 ` syzbot
2025-10-12 10:02 ` syzbot
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