INFO: task udevd:5857 blocked for more than 143 seconds.
Not tainted 6.14.0-rc7-syzkaller-01413-gd9917c7d533c #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:21856 pid:5857 tgid:5857 ppid:1 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5378 [inline]
__schedule+0x190e/0x4c90 kernel/sched/core.c:6765
__schedule_loop kernel/sched/core.c:6842 [inline]
schedule+0x14b/0x320 kernel/sched/core.c:6857
schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99
wait_for_reconnect drivers/block/nbd.c:1104 [inline]
nbd_handle_cmd drivers/block/nbd.c:1146 [inline]
nbd_queue_rq+0x6dd/0xef0 drivers/block/nbd.c:1204
blk_mq_dispatch_rq_list+0xad3/0x19d0 block/blk-mq.c:2120
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:170 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:184 [inline]
__blk_mq_sched_dispatch_requests+0xb8a/0x1840 block/blk-mq-sched.c:309
blk_mq_sched_dispatch_requests+0xd6/0x190 block/blk-mq-sched.c:331
blk_mq_run_hw_queue+0x354/0x500 block/blk-mq.c:2354
blk_mq_flush_plug_list+0x118e/0x1870 block/blk-mq.c:2917
__blk_flush_plug+0x420/0x500 block/blk-core.c:1213
blk_finish_plug block/blk-core.c:1240 [inline]
__submit_bio+0x54a/0x6a0 block/blk-core.c:642
__submit_bio_noacct_mq block/blk-core.c:715 [inline]
submit_bio_noacct_nocheck+0x4d3/0xe30 block/blk-core.c:744
submit_bh fs/buffer.c:2819 [inline]
block_read_full_folio+0x9b3/0xae0 fs/buffer.c:2446
filemap_read_folio+0x148/0x3b0 mm/filemap.c:2400
do_read_cache_folio+0x373/0x5b0 mm/filemap.c:3884
read_mapping_folio include/linux/pagemap.h:1023 [inline]
read_part_sector+0xb3/0x260 block/partitions/core.c:722
adfspart_check_ICS+0xcb/0xa20 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x77f/0x14d0 block/partitions/core.c:693
blkdev_get_whole+0x2d2/0x450 block/bdev.c:706
bdev_open+0x2d4/0xc50 block/bdev.c:915
blkdev_open+0x38e/0x4e0 block/fops.c:652
do_dentry_open+0xdec/0x1960 fs/open.c:956
vfs_open+0x3b/0x370 fs/open.c:1086
do_open fs/namei.c:3830 [inline]
path_openat+0x2c81/0x3590 fs/namei.c:3989
do_filp_open+0x27f/0x4e0 fs/namei.c:4016
do_sys_openat2+0x13e/0x1d0 fs/open.c:1428
do_sys_open fs/open.c:1443 [inline]
__do_sys_openat fs/open.c:1459 [inline]
__se_sys_openat fs/open.c:1454 [inline]
__x64_sys_openat+0x247/0x2a0 fs/open.c:1454
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f19c1f169a4
RSP: 002b:00007ffd2409fa60 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055bb4f908e80 RCX: 00007f19c1f169a4
RDX: 00000000000a0800 RSI: 000055bb4f8e95f0 RDI: 00000000ffffff9c
RBP: 000055bb4f8e95f0 R08: 0000000000000001 R09: 7fffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800
R13: 000055bb4f909320 R14: 0000000000000001 R15: 000055bb4f8e8910
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
2 locks held by getty/5591:
#0: ffff8880318ac0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5835:
3 locks held by udevd/5857:
#0: ffff888142f8d4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903
#1: ffff88802552ef10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:164 [inline]
#1: ffff88802552ef10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:256 [inline]
#1: ffff88802552ef10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x32b/0x500 block/blk-mq.c:2354
#2: ffff8880260a7178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xcf/0xef0 drivers/block/nbd.c:1196
3 locks held by udevd/6239:
#0: ffff88802602b4c8 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf0/0xc50 block/bdev.c:903
#1: ffff88802557c410 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:164 [inline]
#1: ffff88802557c410 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:256 [inline]
#1: ffff88802557c410 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x32b/0x500 block/blk-mq.c:2354
#2: ffff8880260de178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xcf/0xef0 drivers/block/nbd.c:1196
2 locks held by kworker/u8:31/10643:
#0: ffff8880b873e998 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598
#1: ffff8880b8728948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987
3 locks held by syz.0.1405/10955:
#0: ffff88805c6f6208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
#0: ffff88805c6f6208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline]
#0: ffff88805c6f6208 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1389
#1: ffff888079e05258 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1615 [inline]
#1: ffff888079e05258 (sk_lock-AF_CAN){+.+.}-{0:0}, at: bcm_release+0x1eb/0x950 net/can/bcm.c:1575
#2: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:334 [inline]
#2: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:996
2 locks held by syz.2.1406/10971:
#0: ffff88805c52ee08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:877 [inline]
#0: ffff88805c52ee08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: __sock_release net/socket.c:646 [inline]
#0: ffff88805c52ee08 (&sb->s_type->i_mutex_key#10){+.+.}-{4:4}, at: sock_close+0x90/0x240 net/socket.c:1389
#1: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline]
#1: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:996
=============================================
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc7-syzkaller-01413-gd9917c7d533c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
watchdog+0x1058/0x10a0 kernel/hung_task.c:399
kthread+0x7a9/0x920 kernel/kthread.c:464
ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111