syzbot


WARNING in __alloc_workqueue (2)

Status: upstream: reported C repro on 2026/06/09 23:04
Subsystems: btrfs
Labels: prio:low
[Documentation on labels]
Reported-by: syzbot+f80c62f371ba6a1e7d79@syzkaller.appspotmail.com
First crash: 1d21h, last: 1h58m
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
47afab22-f3f8-4ba6-a4e4-5eef3bb52afe assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ WARNING in __alloc_workqueue (2) 2026/06/09 11:51 2026/06/09 11:51 2026/06/09 12:35 c36c07f6c1f2230a36374cbd22235f635e8f9284
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] wifi: ath6kl: fix invalid workqueue flags in ath6kl_usb_create() 2 (2) 2026/06/10 11:00
[syzbot] [btrfs?] WARNING in __alloc_workqueue (2) 0 (1) 2026/06/09 23:04
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in __alloc_workqueue wireless -1 C 2111 142d 181d 0/29 auto-obsoleted due to no activity on 2026/04/13 14:48

Sample crash report:
usb 1-1: config 0 interface 0 altsetting 0 has an invalid descriptor for endpoint zero, skipping
usb 1-1: New USB device found, idVendor=0cf3, idProduct=9374, bcdDevice=bc.3b
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
------------[ cut here ]------------
workqueue: ath6kl_wq is using neither WQ_PERCPU or WQ_UNBOUND. Setting WQ_PERCPU.
WARNING: kernel/workqueue.c:5856 at __alloc_workqueue+0x1d02/0x2070 kernel/workqueue.c:5855, CPU#0: kworker/0:3/5630
Modules linked in:
CPU: 0 UID: 0 PID: 5630 Comm: kworker/0:3 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: usb_hub_wq hub_event
RIP: 0010:__alloc_workqueue+0x1d07/0x2070 kernel/workqueue.c:5855
Code: e9 36 f9 ff ff e8 e9 89 37 00 e9 05 fb ff ff e8 df 89 37 00 e9 92 fb ff ff e8 d5 89 37 00 48 8d 3d 1e b7 43 0e 48 8b 74 24 20 <67> 48 0f b9 3a 81 cd 00 01 00 00 e9 88 e5 ff ff e8 b4 89 37 00 48
RSP: 0018:ffffc90004606bc8 EFLAGS: 00010293
RAX: ffffffff818e312b RBX: 0000000000000000 RCX: ffff8880342dbe00
RDX: 0000000000000000 RSI: ffff8880448f3d68 RDI: ffffffff8fd1e850
RBP: 0000000000000000 R08: ffff8880342dbe00 R09: 0000000000000002
R10: 0000000000000100 R11: 0000000000000102 R12: dffffc0000000000
R13: ffff8880448f3c00 R14: ffffc90004606ce0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125a76000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdb09f620f5 CR3: 0000000028f60000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 alloc_workqueue_va kernel/workqueue.c:5950 [inline]
 alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5966
 ath6kl_usb_create drivers/net/wireless/ath/ath6kl/usb.c:639 [inline]
 ath6kl_usb_probe+0xaa/0x1580 drivers/net/wireless/ath/ath6kl/usb.c:1143
 usb_probe_interface+0x659/0xc70 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:706
 __driver_probe_device+0x1e2/0x350 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x25b/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c8/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12d/0x220 drivers/base/bus.c:620
 device_add+0x7ec/0xb90 drivers/base/core.c:3772
 usb_set_configuration+0x1a87/0x2110 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c4/0x3b0 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x267/0xaf0 drivers/base/dd.c:706
 __driver_probe_device+0x1e2/0x350 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x25b/0x2f0 drivers/base/bus.c:500
 __device_attach+0x2c8/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12d/0x220 drivers/base/bus.c:620
 device_add+0x7ec/0xb90 drivers/base/core.c:3772
 usb_new_device+0x9f8/0x16e0 drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x2a49/0x4f60 drivers/usb/core/hub.c:5953
 process_one_work+0x98b/0x1630 kernel/workqueue.c:3326
 process_scheduled_works kernel/workqueue.c:3409 [inline]
 worker_thread+0xb49/0x1140 kernel/workqueue.c:3490
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
----------------
Code disassembly (best guess):
   0:	e9 36 f9 ff ff       	jmp    0xfffff93b
   5:	e8 e9 89 37 00       	call   0x3789f3
   a:	e9 05 fb ff ff       	jmp    0xfffffb14
   f:	e8 df 89 37 00       	call   0x3789f3
  14:	e9 92 fb ff ff       	jmp    0xfffffbab
  19:	e8 d5 89 37 00       	call   0x3789f3
  1e:	48 8d 3d 1e b7 43 0e 	lea    0xe43b71e(%rip),%rdi        # 0xe43b743
  25:	48 8b 74 24 20       	mov    0x20(%rsp),%rsi
* 2a:	67 48 0f b9 3a       	ud1    (%edx),%rdi <-- trapping instruction
  2f:	81 cd 00 01 00 00    	or     $0x100,%ebp
  35:	e9 88 e5 ff ff       	jmp    0xffffe5c2
  3a:	e8 b4 89 37 00       	call   0x3789f3
  3f:	48                   	rex.W

Crashes (1379):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/08 19:59 linux-next a87737435cfa 656e94c6 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __alloc_workqueue
2026/06/10 11:57 linux-next 49e02880ec0a f79bac11 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 11:38 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 11:17 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 09:46 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 09:46 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 06:42 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 06:25 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 05:52 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 05:27 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 05:08 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 04:57 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 03:28 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __alloc_workqueue
2026/06/10 03:28 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __alloc_workqueue
2026/06/10 02:28 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 02:14 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/10 01:08 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce WARNING in __alloc_workqueue
2026/06/09 23:29 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 23:22 linux-next 49e02880ec0a 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 22:44 linux-next 49e02880ec0a c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 19:48 linux-next 49e02880ec0a c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 19:41 linux-next 49e02880ec0a c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 18:59 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 17:56 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 17:38 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 17:18 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 17:02 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 15:03 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 15:00 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 11:14 linux-next a87737435cfa c36c07f6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 10:48 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 10:41 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 10:32 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 10:24 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 09:54 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 08:55 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 08:09 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 07:53 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 07:40 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 07:25 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 07:12 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 07:08 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 05:54 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
2026/06/09 05:36 linux-next a87737435cfa 656e94c6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root WARNING in __alloc_workqueue
* Struck through repros no longer work on HEAD.