[syzbot] [nvme?] linux-next test error: WARNING in __alloc_workqueue

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 7da7f0711261 Add linux-next specific files for 20260529
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1083d67e580000
kernel config: https://syzkaller.appspot.com/x/.config?x=a40d26c705073da7
dashboard link: https://syzkaller.appspot.com/bug?extid=d078cba4418e65f61984
compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c8bdcda3b30c/disk-7da7f071.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c571d67d2763/vmlinux-7da7f071.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6bdf4a6a4922/bzImage-7da7f071.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d078cb...@syzkaller.appspotmail.com

ACPI: button: Power Button [PWRF]
input: Sleep Button as /devices/platform/LNXSLPBN:00/input/input1
ACPI: button: Sleep Button [SLPF]
ioatdma: Intel(R) QuickData Technology Driver 5.00
ACPI: \_SB_.LNKC: Enabled at IRQ 11
virtio-pci 0000:00:03.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKD: Enabled at IRQ 10
virtio-pci 0000:00:04.0: virtio_pci: leaving for legacy driver
ACPI: \_SB_.LNKB: Enabled at IRQ 10
virtio-pci 0000:00:06.0: virtio_pci: leaving for legacy driver
virtio-pci 0000:00:07.0: virtio_pci: leaving for legacy driver
N_HDLC line discipline registered with maxframe=4096
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
00:02: ttyS0 at I/O 0x3f8 (irq = 4, base_baud = 115200) is a 16550A
00:03: ttyS1 at I/O 0x2f8 (irq = 3, base_baud = 115200) is a 16550A
00:04: ttyS2 at I/O 0x3e8 (irq = 6, base_baud = 115200) is a 16550A
00:05: ttyS3 at I/O 0x2e8 (irq = 7, base_baud = 115200) is a 16550A
Non-volatile memory driver v1.3
usbcore: registered new interface driver xillyusb
ACPI: bus type drm_connector registered
[drm] Initialized vgem 1.0.0 for vgem on minor 0
[drm] Initialized vkms 1.0.0 for vkms on minor 1
Console: switching to colour frame buffer device 128x48
faux_driver vkms: [drm] fb0: vkmsdrmfb frame buffer device
usbcore: registered new interface driver udl
usbcore: registered new interface driver gm12u320
usbcore: registered new interface driver gud
brd: module loaded
loop: module loaded
zram: Added device: zram0
null_blk: disk nullb0 created
null_blk: module loaded
rnull_mod: Rust null_blk loaded
Guest personality initialized and is inactive
VMCI host device registered (name=vmci, major=10, minor=267)
Initialized host personality
usbcore: registered new interface driver rtsx_usb
usbcore: registered new interface driver viperboard
usbcore: registered new interface driver dln2
usbcore: registered new interface driver pn533_usb
nfcsim 0.2 initialized
usbcore: registered new interface driver port100
usbcore: registered new interface driver nfcmrvl
Loading iSCSI transport class v2.0-870.
virtio_scsi virtio0: 1/0/0 default/read/poll queues
scsi host0: Virtio SCSI HBA
blk-mq: reduced tag depth to 10240
st: Version 20160209, fixed bufsize 32768, s/g segs 256
------------[ cut here ]------------
workqueue: nvme_tcp_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: swapper/0/1
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__alloc_workqueue+0x1d07/0x2070 kernel/workqueue.c:5855
Code: e9 36 f9 ff ff e8 29 8a 37 00 e9 05 fb ff ff e8 1f 8a 37 00 e9 92 fb ff ff e8 15 8a 37 00 48 8d 3d ce a7 23 0e 48 8b 74 24 20 <67> 48 0f b9 3a 81 cd 00 01 00 00 e9 88 e5 ff ff e8 f4 89 37 00 48
RSP: 0000:ffffc900000677a8 EFLAGS: 00010293
RAX: ffffffff818e0c1b RBX: 0000000000000000 RCX: ffff88801d68dd00
RDX: 0000000000000000 RSI: ffff888027f28168 RDI: ffffffff8fb1b3f0
RBP: 0000000000000058 R08: ffff88801d68dd00 R09: 0000000000000002
R10: 0000000000000100 R11: 0000000000000102 R12: dffffc0000000000
R13: ffff888027f28000 R14: ffffc900000678c0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125c7e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff88823ffff000 CR3: 000000000dfb8000 CR4: 00000000003526f0
Call Trace:
<TASK>
alloc_workqueue_va kernel/workqueue.c:5950 [inline]
alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5966
nvme_tcp_init_module+0x27/0x100 drivers/nvme/host/tcp.c:3050
do_one_initcall+0x250/0x870 init/main.c:1347
do_initcall_level+0x104/0x190 init/main.c:1409
do_initcalls+0x59/0xa0 init/main.c:1425
kernel_init_freeable+0x2a6/0x3e0 init/main.c:1658
kernel_init+0x1d/0x1d0 init/main.c:1548
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 29 8a 37 00 call 0x378a33
a: e9 05 fb ff ff jmp 0xfffffb14
f: e8 1f 8a 37 00 call 0x378a33
14: e9 92 fb ff ff jmp 0xfffffbab
19: e8 15 8a 37 00 call 0x378a33
1e: 48 8d 3d ce a7 23 0e lea 0xe23a7ce(%rip),%rdi # 0xe23a7f3
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 f4 89 37 00 call 0x378a33
3f: 48 rex.W


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