INFO: task udevd:5835 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:24280 pid:5835 tgid:5835 ppid:5178 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1107 [inline]
nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
nbd_queue_rq+0xc50/0x1080 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xcea/0x1620 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386
blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949
blk_mq_flush_plug_list block/blk-mq.c:2997 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
submit_bh_wbc+0x59c/0x770 fs/buffer.c:2821
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x4c8/0x8e0 fs/buffer.c:2458
filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xd1/0x370 block/partitions/core.c:723
adfspart_check_ICS+0x93/0x910 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7f8/0xc80 block/partitions/core.c:694
blkdev_get_whole+0x187/0x290 block/bdev.c:764
bdev_open+0x2c7/0xe40 block/bdev.c:973
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2cfaaa7407
RSP: 002b:00007ffd77793060 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2cfb259880 RCX: 00007f2cfaaa7407
RDX: 00000000000a0800 RSI: 0000558305ce46b0 RDI: ffffffffffffff9c
RBP: 0000558305ce12c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000558305f27320
R13: 0000558305f1c8d0 R14: 0000000000000000 R15: 0000558305f27320
INFO: task udevd:6567 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:24280 pid:6567 tgid:6567 ppid:5178 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1107 [inline]
nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
nbd_queue_rq+0xc50/0x1080 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xcea/0x1620 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386
blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949
blk_mq_flush_plug_list block/blk-mq.c:2997 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
submit_bh_wbc+0x59c/0x770 fs/buffer.c:2821
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x4c8/0x8e0 fs/buffer.c:2458
filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xd1/0x370 block/partitions/core.c:723
adfspart_check_ICS+0x93/0x910 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7f8/0xc80 block/partitions/core.c:694
blkdev_get_whole+0x187/0x290 block/bdev.c:764
bdev_open+0x2c7/0xe40 block/bdev.c:973
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2cfaaa7407
RSP: 002b:00007ffd77793060 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2cfb259880 RCX: 00007f2cfaaa7407
RDX: 00000000000a0800 RSI: 0000558305f37180 RDI: ffffffffffffff9c
RBP: 0000558305ce12c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000558305f2fcf0
R13: 0000558305f1c8d0 R14: 0000000000000000 R15: 0000558305f2fcf0
INFO: task udevd:6739 blocked for more than 146 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:24280 pid:6739 tgid:6739 ppid:5178 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1107 [inline]
nbd_handle_cmd drivers/block/nbd.c:1149 [inline]
nbd_queue_rq+0xc50/0x1080 drivers/block/nbd.c:1207
blk_mq_dispatch_rq_list+0x422/0x1e70 block/blk-mq.c:2148
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xcea/0x1620 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x1c0 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x23c/0x670 block/blk-mq.c:2386
blk_mq_dispatch_list+0x51d/0x1360 block/blk-mq.c:2949
blk_mq_flush_plug_list block/blk-mq.c:2997 [inline]
blk_mq_flush_plug_list+0x130/0x600 block/blk-mq.c:2969
__blk_flush_plug+0x2c4/0x4b0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x584/0x6c0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x562/0xc10 block/blk-core.c:753
submit_bio_noacct+0xd17/0x2010 block/blk-core.c:884
blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline]
submit_bh_wbc+0x59c/0x770 fs/buffer.c:2821
submit_bh fs/buffer.c:2826 [inline]
block_read_full_folio+0x4c8/0x8e0 fs/buffer.c:2458
filemap_read_folio+0xfc/0x3b0 mm/filemap.c:2501
do_read_cache_folio+0x2d7/0x6b0 mm/filemap.c:4101
read_mapping_folio include/linux/pagemap.h:1028 [inline]
read_part_sector+0xd1/0x370 block/partitions/core.c:723
adfspart_check_ICS+0x93/0x910 block/partitions/acorn.c:360
check_partition block/partitions/core.c:142 [inline]
blk_add_partitions block/partitions/core.c:590 [inline]
bdev_disk_changed+0x7f8/0xc80 block/partitions/core.c:694
blkdev_get_whole+0x187/0x290 block/bdev.c:764
bdev_open+0x2c7/0xe40 block/bdev.c:973
blkdev_open+0x34e/0x4f0 block/fops.c:697
do_dentry_open+0x6d8/0x1660 fs/open.c:949
vfs_open+0x82/0x3f0 fs/open.c:1081
do_open fs/namei.c:4671 [inline]
path_openat+0x208c/0x31a0 fs/namei.c:4830
do_file_open+0x20e/0x430 fs/namei.c:4859
do_sys_openat2+0x10d/0x1e0 fs/open.c:1366
do_sys_open fs/open.c:1372 [inline]
__do_sys_openat fs/open.c:1388 [inline]
__se_sys_openat fs/open.c:1383 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1383
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2cfaaa7407
RSP: 002b:00007ffd77793060 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f2cfb259880 RCX: 00007f2cfaaa7407
RDX: 00000000000a0800 RSI: 0000558305f21f80 RDI: ffffffffffffff9c
RBP: 0000558305ce12c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055830604c100
R13: 0000558305f1c8d0 R14: 0000000000000000 R15: 000055830604c100
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775
2 locks held by getty/5564:
#0: ffff8880385fb0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211
3 locks held by udevd/5835:
#0: ffff88802788c358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
#1: ffff888027348918 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffff888027348918 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#1: ffff888027348918 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22e/0x670 block/blk-mq.c:2386
#2: ffff8880279b8180 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
3 locks held by udevd/5836:
#0: ffff888027ac6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
#1: ffff88802644e918 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffff88802644e918 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#1: ffff88802644e918 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22e/0x670 block/blk-mq.c:2386
#2: ffff888027b20180 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
3 locks held by udevd/6567:
#0: ffff888027970358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
#1: ffff888027348398 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffff888027348398 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#1: ffff888027348398 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22e/0x670 block/blk-mq.c:2386
#2: ffff888027a00180 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
3 locks held by udevd/6600:
#0: ffff888026cf6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
#1: ffff88802644e218 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffff88802644e218 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#1: ffff88802644e218 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22e/0x670 block/blk-mq.c:2386
#2: ffff888027be0180 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
3 locks held by udevd/6739:
#0: ffff888026cf2358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
#1: ffff88802644e598 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffff88802644e598 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#1: ffff88802644e598 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22e/0x670 block/blk-mq.c:2386
#2: ffff888027bc8180 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
3 locks held by udevd/7098:
#0: ffff888027974358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:961
#1: ffff88802793b998 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline]
#1: ffff88802793b998 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline]
#1: ffff88802793b998 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x22e/0x670 block/blk-mq.c:2386
#2: ffff888027ae8180 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xba/0x1080 drivers/block/nbd.c:1199
3 locks held by syz.4.8176/22898:
2 locks held by syz-executor/22899:
=============================================
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 02/12/2026
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x141/0x190 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
watchdog+0xd25/0x1050 kernel/hung_task.c:515
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 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: 6141 Comm: kworker/0:5 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events delayed_vfree_work
RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:63
Code: c6 20 17 1b 8c 48 c7 c7 60 17 1b 8c e9 f9 fe ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 89 fe 48 c7 c7 a0 17 1b 8c e9 cd fe ff ff 66 2e 0f
RSP: 0018:ffffc90003187948 EFLAGS: 00000046
RAX: ffff88807e108000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8b93ceda RDI: ffffffff8df6b20b
RBP: ffffffff9b45df18 R08: 0000000000000001 R09: 0000000000000000
R10: ffffffff90d9c017 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812433c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2f7fbe7158 CR3: 0000000032070000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
lock_acquire kernel/locking/lockdep.c:5867 [inline]
lock_acquire+0x18c/0x380 kernel/locking/lockdep.c:5825
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
__debug_check_no_obj_freed lib/debugobjects.c:1105 [inline]
debug_check_no_obj_freed+0x1c9/0x630 lib/debugobjects.c:1146
__free_pages_prepare mm/page_alloc.c:1440 [inline]
__free_frozen_pages+0x392/0x10d0 mm/page_alloc.c:2978
vfree.part.0+0x12b/0x9d0 mm/vmalloc.c:3479
vfree mm/vmalloc.c:3456 [inline]
delayed_vfree_work+0x8e/0xd0 mm/vmalloc.c:3398
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245