INFO: task udevd:6168 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:22776 pid:6168 tgid:6168 ppid:5185 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x1190/0x5de0 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:7026
io_schedule+0xbf/0x130 kernel/sched/core.c:7871
folio_wait_bit_common+0x3d5/0x9e0 mm/filemap.c:1330
folio_put_wait_locked mm/filemap.c:1494 [inline]
do_read_cache_folio+0x342/0x5c0 mm/filemap.c:4006
read_mapping_folio include/linux/pagemap.h:999 [inline]
read_part_sector+0xd4/0x370 block/partitions/core.c:722
adfspart_check_POWERTEC+0x8a/0x710 block/partitions/acorn.c:454
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x723/0x1520 block/partitions/core.c:693
blkdev_get_whole+0x187/0x290 block/bdev.c:748
bdev_open+0x2c7/0xe40 block/bdev.c:957
blkdev_open+0x34e/0x4f0 block/fops.c:701
do_dentry_open+0x982/0x1530 fs/open.c:965
vfs_open+0x82/0x3f0 fs/open.c:1097
do_open fs/namei.c:3975 [inline]
path_openat+0x1de4/0x2cb0 fs/namei.c:4134
do_filp_open+0x20b/0x470 fs/namei.c:4161
do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x174/0x210 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efcf94a7407
RSP: 002b:00007fffe62f6c70 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007efcf9c04880 RCX: 00007efcf94a7407
RDX: 00000000000a0800 RSI: 0000557982306500 RDI: ffffffffffffff9c
RBP: 00005579820cb2c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000557982311320
R13: 00005579823068d0 R14: 0000000000000000 R15: 0000557982311320
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
1 lock held by syz-executor/5798:
#0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline]
#0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631
1 lock held by udevd/6168:
#0: ffff888142fbe358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945
5 locks held by kworker/1:7/7934:
#0: ffff888143ea2d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc90003087d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
#2: ffff888029968198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#2: ffff888029968198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x4fe0 drivers/usb/core/hub.c:5898
#3: ffff88801bb44198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#3: ffff88801bb44198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
#4: ffff8880536e9160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff8880536e9160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4b0 drivers/base/dd.c:1006
2 locks held by kworker/u8:15/7937:
#0: ffff8881466c3148 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238
#1: ffffc90003a47d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239
2 locks held by getty/8441:
#0: ffff88814db0f0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc900036342f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf3f/0x1170 kernel/hung_task.c:495
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10412 Comm: cmp Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:218 [inline]
RIP: 0010:unwind_next_frame+0x23d/0x20a0 arch/x86/kernel/unwind_orc.c:494
Code: 89 74 24 20 89 44 24 18 e8 50 82 b9 00 48 8b 4c 24 30 48 8b 44 24 28 8b 74 24 20 44 8b 5c 24 18 8d 50 01 8b 0c 8d cc 9b d0 91 <48> b8 00 00 00 00 00 fc ff df 48 8d 3c 95 cc 9b d0 91 49 89 f8 49
RSP: 0018:ffffc900053af348 EFLAGS: 00000246
RAX: 00000000000115df RBX: 0000000000000001 RCX: 000000000003485c
RDX: 00000000000115e0 RSI: 00000000000a6469 RDI: ffffffff91d4f348
RBP: ffffc900053af400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 00000000000115df R12: ffffc900053af408
R13: ffffc900053af3b8 R14: ffffc900053af3ed R15: ffffffff8215df9a
FS: 0000000000000000(0000) GS:ffff888124a08000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5ae70c2000 CR3: 000000006cd87000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 3a810b1eb6134bdc DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:559
slab_free_hook mm/slub.c:2500 [inline]
slab_free mm/slub.c:6634 [inline]
kmem_cache_free+0x15e/0x6c0 mm/slub.c:6744
vms_complete_munmap_vmas+0x573/0x970 mm/vma.c:1293
__mmap_complete mm/vma.c:2532 [inline]
__mmap_region+0x969/0x27a0 mm/vma.c:2678
mmap_region+0x1ab/0x3f0 mm/vma.c:2740
do_mmap+0xa3e/0x1210 mm/mmap.c:558
vm_mmap_pgoff+0x29e/0x470 mm/util.c:581
ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:604
__do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
__se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
__x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5ae73eb242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007fff945335a8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f5ae70ba000 RCX: 00007f5ae73eb242
RDX: 0000000000000005 RSI: 0000000000003000 RDI: 00007f5ae70ba000
RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000002000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007fff945335f8
R13: 00007f5ae70c20c0 R14: 00007fff945339e0 R15: 00000ffff28a66b8