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AHgh+RrsqOrcxtC1yOxR18Pd4Gjf9/SBPF2zQp8OqSjaU2800BDseGe7rGMhx1UI8mnxQw2UnsCNAMMZgvxVySM=@vger.kernel.org X-Gm-Message-State: AOJu0YwMLlwlcigjlA6yr49zo1zdxCJqAdwLe58O9eNeXFXC1Rdx+Rzv uhebEZZGkhj7FqpBiNX+aoNX8+BbEHMaW1DI59SQ0gBFXDK5Uw3wk3I1Z8s2qrffG8ybgO13/Hx ywRreTECIgybO/N1niOqaT5CgP4WIsk0bQvRkEVNKAplAY81KOnHpCRcrKtE= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4cc2:b0:6ac:a539:bc41 with SMTP id 006d021491bc7-6b041f59187mr4805815eaf.12.1786208309144; Sat, 08 Aug 2026 09:58:29 -0700 (PDT) Date: Sat, 08 Aug 2026 09:58:29 -0700 In-Reply-To: <0000000000004e50e40616038e72@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <6a776035.01d0871a.3a0d52.0063.GAE@google.com> Subject: Re: [syzbot] [bluetooth?] WARNING in l2cap_chan_send From: syzbot To: johan.hedberg@gmail.com, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, luiz.dentz@gmail.com, marcel@holtmann.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" syzbot has found a reproducer for the following issue on: HEAD commit: a7c7074b58d2 Merge tag 'fbdev-for-7.2-rc7' of git://git.ke.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=171c0149580000 kernel config: https://syzkaller.appspot.com/x/.config?x=b924ab49cf8bae2a dashboard link: https://syzkaller.appspot.com/bug?extid=b6919040d9958e2fc1ae compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=109c0149580000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+b6919040d9958e2fc1ae@syzkaller.appspotmail.com ------------[ cut here ]------------ workqueue: cannot queue hci_tx_work on wq hci0 WARNING: kernel/workqueue.c:2306 at __queue_work+0xd4a/0x1090 kernel/workqueue.c:2305, CPU#1: syz-executor109/5985 Modules linked in: CPU: 1 UID: 0 PID: 5985 Comm: syz-executor109 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__queue_work+0xd66/0x1090 kernel/workqueue.c:2305 Code: 49 81 c7 70 01 00 00 4c 8d 35 86 dd 5b 0e 48 89 f8 48 c1 e8 03 80 3c 18 00 74 05 e8 a4 20 a5 00 49 8b 75 18 4c 89 f7 4c 89 fa <67> 48 0f b9 3a 4c 89 e8 48 c1 e8 03 80 3c 18 00 74 08 4c 89 ef e8 RSP: 0018:ffffc900032d7510 EFLAGS: 00010046 RAX: 1ffff11004fd798a RBX: dffffc0000000000 RCX: ffff8880308b1f00 RDX: ffff88807d1c0970 RSI: ffffffff8a85e850 RDI: ffffffff8fe7e260 RBP: 0000000000000000 R08: ffff888027ebcc3f R09: 1ffff11004fd7987 R10: dffffc0000000000 R11: ffffed1004fd7988 R12: 0000000000000008 R13: ffff888027ebcc38 R14: ffffffff8fe7e260 R15: ffff88807d1c0970 FS: 00007fed8a7926c0(0000) GS:ffff888125866000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fed8c796d58 CR3: 00000000739ba000 CR4: 00000000003526f0 Call Trace: queue_work_on+0x106/0x1c0 kernel/workqueue.c:2452 l2cap_chan_send+0x168a/0x22f0 net/bluetooth/l2cap_core.c:-1 l2cap_sock_sendmsg+0x33a/0x4d0 net/bluetooth/l2cap_sock.c:1180 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] ____sys_sendmsg+0x54e/0x850 net/socket.c:2684 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2738 __sys_sendmmsg+0x273/0x4d0 net/socket.c:2827 __do_sys_sendmmsg net/socket.c:2854 [inline] __se_sys_sendmmsg net/socket.c:2851 [inline] __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2851 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0x560 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fed8cfcb649 Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fed8a791f58 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000000001f2 RCX: 00007fed8cfcb649 RDX: 000000000000000a RSI: 00007fed8a791f80 RDI: 0000000000000006 RBP: 00007fed8a791f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000006 R13: 0000000000000000 R14: 00007ffed10ed450 R15: 00007ffed10ed538 ---------------- Code disassembly (best guess): 0: 49 81 c7 70 01 00 00 add $0x170,%r15 7: 4c 8d 35 86 dd 5b 0e lea 0xe5bdd86(%rip),%r14 # 0xe5bdd94 e: 48 89 f8 mov %rdi,%rax 11: 48 c1 e8 03 shr $0x3,%rax 15: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 19: 74 05 je 0x20 1b: e8 a4 20 a5 00 call 0xa520c4 20: 49 8b 75 18 mov 0x18(%r13),%rsi 24: 4c 89 f7 mov %r14,%rdi 27: 4c 89 fa mov %r15,%rdx * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 4c 89 e8 mov %r13,%rax 32: 48 c1 e8 03 shr $0x3,%rax 36: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 3a: 74 08 je 0x44 3c: 4c 89 ef mov %r13,%rdi 3f: e8 .byte 0xe8 --- 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.