From: syzbot <syzbot+039eab266c6321a174bd@syzkaller.appspotmail.com>
To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, pasha.tatashin@soleen.com,
syzkaller-bugs@googlegroups.com
Subject: [syzbot] [mm?] INFO: rcu detected stall in hub_event (2)
Date: Wed, 20 Aug 2025 19:14:31 -0700 [thread overview]
Message-ID: <68a68107.050a0220.1f0557.0000.GAE@google.com> (raw)
Hello,
syzbot found the following issue on:
HEAD commit: 90d970cade8e Merge tag 'ata-ata-6.17-rc2' of git://git.ker..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1193b3a2580000
kernel config: https://syzkaller.appspot.com/x/.config?x=c5d01e11121d45
dashboard link: https://syzkaller.appspot.com/bug?extid=039eab266c6321a174bd
compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/104fc9d3de89/disk-90d970ca.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/59eb5344d41f/vmlinux-90d970ca.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e0bed540b10c/bzImage-90d970ca.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+039eab266c6321a174bd@syzkaller.appspotmail.com
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9643/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=87629, q=1145 ncpus=2)
task:kworker/1:13 state:R running task stack:22384 pid:9643 tgid:9643 ppid:2 task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6961
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
irqentry_exit+0x36/0x90 kernel/entry/common.c:197
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:246
Code: 8b 05 58 b3 1a 12 a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 3c 16 00 00 85 c0 74 4f <8b> 82 18 16 00 00 83 f8 03 75 44 48 8b 82 20 16 00 00 8b 92 1c 16
RSP: 0000:ffffc90004fdf430 EFLAGS: 00000246
RAX: 0000000080000000 RBX: 0000000000000004 RCX: ffffffff822dbf07
RDX: ffff88802883a440 RSI: 0000000000000004 RDI: 0000000000000006
RBP: 0000000000000003 R08: 0000000000000006 R09: 0000000000000004
R10: 0000000000000003 R11: 00000000000082fe R12: ffff8880200096f0
R13: ffff8880200096ec R14: 0000000000000002 R15: dffffc0000000000
__page_table_check_zero+0x207/0x5d0 mm/page_table_check.c:139
page_table_check_free include/linux/page_table_check.h:43 [inline]
free_pages_prepare mm/page_alloc.c:1396 [inline]
__free_frozen_pages+0x7b7/0x10f0 mm/page_alloc.c:2895
discard_slab mm/slub.c:2753 [inline]
__put_partials+0x165/0x1c0 mm/slub.c:3218
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:340
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4180 [inline]
slab_alloc_node mm/slub.c:4229 [inline]
kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4281
__alloc_skb+0x2b2/0x380 net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
alloc_uevent_skb+0x7d/0x210 lib/kobject_uevent.c:289
uevent_net_broadcast_untagged lib/kobject_uevent.c:326 [inline]
kobject_uevent_net_broadcast lib/kobject_uevent.c:410 [inline]
kobject_uevent_env+0xca4/0x1870 lib/kobject_uevent.c:608
device_del+0x623/0x9f0 drivers/base/core.c:3896
usb_disable_device+0x355/0x7d0 drivers/usb/core/message.c:1418
usb_disconnect+0x2e1/0x9c0 drivers/usb/core/hub.c:2344
hub_port_connect drivers/usb/core/hub.c:5406 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
port_event drivers/usb/core/hub.c:5870 [inline]
hub_event+0x1c81/0x4fe0 drivers/usb/core/hub.c:5952
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>
---
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next reply other threads:[~2025-08-21 2:14 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-21 2:14 syzbot [this message]
2025-09-06 3:05 ` [syzbot] [kernfs?] [mm?] INFO: rcu detected stall in hub_event (2) syzbot
2026-06-16 11:04 ` [PATCH] Input: yealink - stop URB resubmission on completion error Jie Wang
2026-06-16 3:31 ` sashiko-bot
2026-06-16 19:17 ` Dmitry Torokhov
2025-09-17 17:52 ` [syzbot] [kernfs?] [mm?] INFO: rcu detected stall in hub_event (2) syzbot
2026-06-16 2:05 ` Forwarded: Re: [syzbot] INFO: rcu detected stall in hub_event syzbot
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