From: syzbot <syzbot+5897b3c764f5989ea942@syzkaller.appspotmail.com>
To: johan.hedberg@gmail.com, linux-bluetooth@vger.kernel.org,
linux-kernel@vger.kernel.org, luiz.dentz@gmail.com,
marcel@holtmann.org, syzkaller-bugs@googlegroups.com
Subject: Re: [syzbot] [bluetooth?] WARNING in hci_connect_sco
Date: Sat, 31 Jan 2026 05:50:28 -0800 [thread overview]
Message-ID: <697e08a4.050a0220.16b13.0092.GAE@google.com> (raw)
In-Reply-To: <694c9ee9.050a0220.35954c.0030.GAE@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: ad9a728a3388 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15513c5a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671
dashboard link: https://syzkaller.appspot.com/bug?extid=5897b3c764f5989ea942
compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17b45322580000
Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-ad9a728a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/bad71633ff53/vmlinux-ad9a728a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7cac661e37c7/bzImage-ad9a728a.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5897b3c764f5989ea942@syzkaller.appspotmail.com
------------[ cut here ]------------
workqueue: cannot queue hci_conn_timeout on wq hci1
WARNING: kernel/workqueue.c:2251 at __queue_work+0xcbb/0x10f0 kernel/workqueue.c:2250, CPU#1: syz.0.8416/24058
Modules linked in:
CPU: 1 UID: 0 PID: 24058 Comm: syz.0.8416 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__queue_work+0xcbf/0x10f0 kernel/workqueue.c:2250
Code: 00 00 00 fc ff df 49 8d 94 24 78 01 00 00 48 89 f9 48 c1 e9 03 80 3c 01 00 0f 85 15 04 00 00 48 8d 3d 95 f5 eb 0e 48 8b 75 18 <67> 48 0f b9 3a e9 77 f7 ff ff e8 a2 b0 38 00 90 0f 0b 90 e9 ff f5
RSP: 0018:ffffc90005f2fbf8 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 1ffff11006ee094b
RDX: ffff888027001178 RSI: ffffffff8a71b840 RDI: ffffffff90ba4040
RBP: ffff888037704a40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888027001000
R13: ffff888048858000 R14: ffff888037704a88 R15: ffff888037704a48
FS: 00007fa16e9826c0(0000) GS:ffff8880d66d9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000000c0 CR3: 00000000523e6000 CR4: 0000000000352ef0
Call Trace:
<TASK>
__queue_delayed_work+0x365/0x470 kernel/workqueue.c:2503
queue_delayed_work_on+0x180/0x1e0 kernel/workqueue.c:2555
queue_delayed_work include/linux/workqueue.h:684 [inline]
hci_conn_drop include/net/bluetooth/hci_core.h:1710 [inline]
hci_conn_drop include/net/bluetooth/hci_core.h:1684 [inline]
hci_connect_sco+0x4d2/0xef0 net/bluetooth/hci_conn.c:1767
sco_connect net/bluetooth/sco.c:339 [inline]
sco_sock_connect+0x303/0xcb0 net/bluetooth/sco.c:665
__sys_connect_file+0x141/0x1a0 net/socket.c:2089
__sys_connect+0x141/0x170 net/socket.c:2108
__do_sys_connect net/socket.c:2114 [inline]
__se_sys_connect net/socket.c:2111 [inline]
__x64_sys_connect+0x72/0xb0 net/socket.c:2111
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa16db9aeb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa16e982028 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 00007fa16de15fa0 RCX: 00007fa16db9aeb9
RDX: 0000000000000008 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007fa16dc08c1f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa16de16038 R14: 00007fa16de15fa0 R15: 00007ffcb1740998
</TASK>
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 00 fc add %bh,%ah
4: ff lcall (bad)
5: df 49 8d fisttps -0x73(%rcx)
8: 94 xchg %eax,%esp
9: 24 78 and $0x78,%al
b: 01 00 add %eax,(%rax)
d: 00 48 89 add %cl,-0x77(%rax)
10: f9 stc
11: 48 c1 e9 03 shr $0x3,%rcx
15: 80 3c 01 00 cmpb $0x0,(%rcx,%rax,1)
19: 0f 85 15 04 00 00 jne 0x434
1f: 48 8d 3d 95 f5 eb 0e lea 0xeebf595(%rip),%rdi # 0xeebf5bb
26: 48 8b 75 18 mov 0x18(%rbp),%rsi
* 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction
2f: e9 77 f7 ff ff jmp 0xfffff7ab
34: e8 a2 b0 38 00 call 0x38b0db
39: 90 nop
3a: 0f 0b ud2
3c: 90 nop
3d: e9 .byte 0xe9
3e: ff f5 push %rbp
---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
next prev parent reply other threads:[~2026-01-31 13:50 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-25 2:18 [syzbot] [bluetooth?] WARNING in hci_connect_sco syzbot
2026-01-31 13:50 ` syzbot [this message]
2026-02-01 2:15 ` Hillf Danton
2026-02-01 2:34 ` syzbot
2026-02-02 1:12 ` Hillf Danton
2026-02-02 1:32 ` syzbot
2026-10-17 14:01 ` syzbot
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