INFO: task udevd:4495 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:23392 pid: 4495 ppid: 3562 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
io_schedule+0x7c/0xd0 kernel/sched/core.c:8503
wait_on_page_bit_common+0x815/0xe00 mm/filemap.c:1356
wait_on_page_bit mm/filemap.c:1417 [inline]
wait_on_page_locked include/linux/pagemap.h:688 [inline]
wait_on_page_read mm/filemap.c:3437 [inline]
do_read_cache_page+0xb05/0x1030 mm/filemap.c:3480
read_mapping_page include/linux/pagemap.h:515 [inline]
read_part_sector+0xd4/0x4f0 block/partitions/core.c:731
adfspart_check_ICS+0xbf/0xe00 block/partitions/acorn.c:360
check_partition block/partitions/core.c:148 [inline]
blk_add_partitions block/partitions/core.c:616 [inline]
bdev_disk_changed+0x917/0x16b0 block/partitions/core.c:702
blkdev_get_whole+0x2f9/0x390 block/bdev.c:682
blkdev_get_by_dev+0x2d0/0xa60 block/bdev.c:827
blkdev_open+0x12d/0x2c0 block/fops.c:466
do_dentry_open+0x7ff/0xf80 fs/open.c:826
do_open fs/namei.c:3608 [inline]
path_openat+0x2682/0x2f30 fs/namei.c:3742
do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
do_sys_openat2+0x142/0x4a0 fs/open.c:1253
do_sys_open fs/open.c:1269 [inline]
__do_sys_openat fs/open.c:1285 [inline]
__se_sys_openat fs/open.c:1280 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1280
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f3893254407
RSP: 002b:00007ffee9ac6170 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3893166880 RCX: 00007f3893254407
RDX: 00000000000a0800 RSI: 000055d20d80b360 RDI: ffffffffffffff9c
RBP: 000055d20d80a910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055d20d827f10
R13: 000055d20d822410 R14: 0000000000000000 R15: 000055d20d827f10
Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by udevd/3562:
2 locks held by getty/3954:
#0: ffff88802b8a5098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc90002d032e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
6 locks held by kworker/0:5/4229:
#0: ffff8880179f6138 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc90002edfd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff888023492220 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:760 [inline]
#2: ffff888023492220 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x5560 drivers/usb/core/hub.c:5827
#3: ffff8880234955c0 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3168 [inline]
#3: ffff8880234955c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5393 [inline]
#3: ffff8880234955c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
#3: ffff8880234955c0 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5799 [inline]
#3: ffff8880234955c0 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x30f2/0x5560 drivers/usb/core/hub.c:5881
#4: ffff8881489c7768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5394 [inline]
#4: ffff8881489c7768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5637 [inline]
#4: ffff8881489c7768 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5799 [inline]
#4: ffff8881489c7768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x3124/0x5560 drivers/usb/core/hub.c:5881
#5: ffffffff8cb97ab0 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x14f/0x18d0 drivers/usb/core/hub.c:3030
3 locks held by kworker/u4:11/4483:
1 lock held by udevd/4495:
#0: ffff88801f82a918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
1 lock held by udevd/4988:
1 lock held by udevd/6042:
1 lock held by syz.6.1041/8285:
#0: ffff888147e39468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
3 locks held by syz.5.1043/8296:
2 locks held by syz.1.1045/8300:
1 lock held by dhcpcd/8301:
2 locks held by syz.2.1046/8302:
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6042 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:360 [inline]
RIP: 0010:unwind_next_frame+0x9bf/0x1d90 arch/x86/kernel/unwind_orc.c:539
Code: df 80 3c 08 00 74 05 e8 2f b1 87 00 48 8b 73 28 48 8d 4b 20 4c 89 ff 48 89 da e8 cc 86 f5 ff 85 c0 0f 85 5d 0b 00 00 4c 89 ff 2c 1c 00 00 49 89 c7 49 bd 00 00 00 00 00 fc ff df 48 8b 44 24
RSP: 0018:ffffc9000469f728 EFLAGS: 00000202
RAX: ffffc9000469fc01 RBX: ffffc9000469f7e8 RCX: 1ffff920008d3e01
RDX: 1ffffffff1bdea15 RSI: ffffffff8def50aa RDI: ffffc9000469fc98
RBP: ffffc9000469f830 R08: 0000000000000008 R09: 0000000000000005
R10: fffff520008d3f09 R11: 1ffff920008d3f07 R12: 1ffffffff1bdea15
R13: ffffc900046a0000 R14: ffffc90004698000 R15: ffffc9000469fc98
FS: 00007f3893166880(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3357ce CR3: 000000007e565000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1710 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kmem_cache_free+0x8f/0x210 mm/slub.c:3520
putname fs/namei.c:271 [inline]
user_path_at_empty+0x13e/0x190 fs/namei.c:2885
user_path_at include/linux/namei.h:57 [inline]
vfs_statx+0x102/0x4d0 fs/stat.c:221
vfs_fstatat fs/stat.c:243 [inline]
__do_sys_newfstatat fs/stat.c:411 [inline]
__se_sys_newfstatat fs/stat.c:405 [inline]
__x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f38932beb0a
Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7
RSP: 002b:00007ffee9ac5368 EFLAGS: 00000206 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffee9ac5d40 RCX: 00007f38932beb0a
RDX: 00007ffee9ac5390 RSI: 00007ffee9ac5d40 RDI: 00000000ffffff9c
RBP: 00007ffee9ac5d4e R08: 0000000000000075 R09: 0000000000000000
R10: 0000000000000100 R11: 0000000000000206 R12: 000055d20d830485
R13: 00007ffee9ac5420 R14: 000055d1e04936d7 R15: 000055d20d830480