syzbot


WARNING in l2cap_chan_send

Status: upstream: reported on 2026/02/05 13:43
Reported-by: syzbot+307f5261162016128e88@syzkaller.appspotmail.com
First crash: 6d02h, last: 6d02h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 WARNING in l2cap_chan_send (2) -1 1 52d 52d 0/3 upstream: reported on 2025/12/21 03:01
upstream WARNING in l2cap_chan_send bluetooth -1 54 17d 668d 0/29 upstream: reported on 2024/04/14 00:26
linux-6.1 WARNING in l2cap_chan_send -1 1 319d 319d 0/3 auto-obsoleted due to no activity on 2025/07/06 18:42

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 8156 at kernel/workqueue.c:1453 __queue_work+0xc04/0xd50 kernel/workqueue.c:1453
Modules linked in:
CPU: 0 PID: 8156 Comm: kbnepd bnep0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__queue_work+0xc04/0xd50 kernel/workqueue.c:1453
Code: fc ff ff 48 8b 4c 24 08 80 e1 07 80 c1 03 38 c1 0f 8c 13 fd ff ff 48 8b 7c 24 08 e8 06 28 70 00 e9 04 fd ff ff e8 ec 23 2b 00 <0f> 0b 48 83 c4 50 5b 41 5c 41 5d 41 5e 41 5f 5d c3 e8 d6 23 2b 00
RSP: 0018:ffffc9000460f7d8 EFLAGS: 00010093
RAX: ffffffff814dfbb4 RBX: 0000000000010000 RCX: ffff88804e900000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffff88807ce60b7f R09: 1ffff1100f9cc16f
R10: dffffc0000000000 R11: ffffed100f9cc170 R12: 0000000000000200
R13: ffff8880227341c0 R14: ffff888022734000 R15: 0000000000000008
FS:  0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f350470950 CR3: 000000006407f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 queue_work_on+0x124/0x1f0 kernel/workqueue.c:1559
 l2cap_chan_send+0x3c5/0x25d0 net/bluetooth/l2cap_core.c:-1
 l2cap_sock_sendmsg+0x1aa/0x2b0 net/bluetooth/l2cap_sock.c:1173
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 sock_sendmsg net/socket.c:741 [inline]
 kernel_sendmsg+0x234/0x350 net/socket.c:765
 bnep_tx_frame net/bluetooth/bnep/core.c:466 [inline]
 bnep_session+0x23df/0x29e0 net/bluetooth/bnep/core.c:509
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/05 13:42 linux-5.15.y 9eec9a14ee10 4936e85c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING in l2cap_chan_send
* Struck through repros no longer work on HEAD.