[syzbot] [bluetooth?] INFO: task hung in get_signal (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7d31f578f323 Add linux-next specific files for 20251128
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17a242b4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ec890b8333fce099
dashboard link: https://syzkaller.appspot.com/bug?extid=edae0f1918326febf965
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=16756512580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/9bcc6eb60940/disk-7d31f578.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/895bc1bfae48/vmlinux-7d31f578.xz
kernel image: https://storage.googleapis.com/syzbot-assets/48f15e4679f3/bzImage-7d31f578.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+edae0f...@syzkaller.appspotmail.com

INFO: task syz-executor:5969 blocked for more than 143 seconds.
Not tainted syzkaller #0
task:syz-executor state:D
Call Trace:
do_wait_for_common kernel/sched/completion.c:100 [inline]
__wait_for_common kernel/sched/completion.c:121 [inline]
wait_for_common kernel/sched/completion.c:132 [inline]
wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153
__flush_work+0x9b9/0xbc0 kernel/workqueue.c:4281
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fac0ed9148a
#2: ffff88807c668ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by kworker/u9:3/5978:
#0: ffff888057c3e948 ((wq_completion)hci6){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc9000412fb80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff88807ef20ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by kworker/u9:4/5979:
#0: ffff88801e7c2148 ((wq_completion)hci4){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc900040afb80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff888054900ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by kworker/u9:5/6113:
#0: ffff8880296d3148 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc90002f17b80 (
(work_completion)(&hdev->cmd_sync_work)
){+.+.}-{0:0}
3 locks held by kworker/u9:9/11288:
#1: ffffc9000411fb80 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff888030d98ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
3 locks held by kworker/u9:10/11292:
#0: ffff88801e7c1148 ((wq_completion)hci4#2){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236
#1: ffffc9000c69fb80 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237
#2: ffff8880549000c0 (&hdev->lock){+.+.}-{4:4}, at: hci_event_packet+0x162/0x1260 net/bluetooth/hci_event.c:7736
7 locks held by kworker/u9:11/12552:


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