INFO: task syz.0.533:7082 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.533 state:D stack:27808 pid:7082 ppid:4270 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832
blkdev_open+0x11e/0x2e0 block/fops.c:500
do_dentry_open+0x7e9/0x10d0 fs/open.c:882
do_open fs/namei.c:3634 [inline]
path_openat+0x25c6/0x2e70 fs/namei.c:3791
do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
do_sys_openat2+0x142/0x490 fs/open.c:1320
do_sys_open fs/open.c:1336 [inline]
__do_sys_openat fs/open.c:1352 [inline]
__se_sys_openat fs/open.c:1347 [inline]
__x64_sys_openat+0x135/0x160 fs/open.c:1347
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa3d7d8df90
RSP: 002b:00007fa3d8d08b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000185402 RCX: 00007fa3d7d8df90
RDX: 0000000000185402 RSI: 00007fa3d8d08c10 RDI: 00000000ffffff9c
RBP: 00007fa3d8d08c10 R08: 0000000000000000 R09: 002364626e2f7665
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007fa3d7fe6038 R14: 00007fa3d7fe5fa0 R15: 00007ffcd8918228
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
3 locks held by kworker/u4:3/51:
2 locks held by getty/4026:
#0: ffff88814d27c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
2 locks held by syz-executor/4267:
#0: ffff888029a380e0 (&type->s_umount_key#50){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362
#1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#1: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x346/0x830 kernel/rcu/tree_exp.h:962
1 lock held by udevd/4273:
#0: ffff8880250da4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832
6 locks held by kworker/0:5/4318:
#0: ffff888148a59538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900044efd00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffff88823bc76190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline]
#2: ffff88823bc76190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1a7/0x54e0 drivers/usb/core/hub.c:5845
#3: ffff8880281304f8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3200 [inline]
#3: ffff8880281304f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5413 [inline]
#3: ffff8880281304f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#3: ffff8880281304f8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#3: ffff8880281304f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x21bd/0x54e0 drivers/usb/core/hub.c:5899
#4: ffff8881457e2768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5414 [inline]
#4: ffff8881457e2768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5657 [inline]
#4: ffff8881457e2768 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5817 [inline]
#4: ffff8881457e2768 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x21ee/0x54e0 drivers/usb/core/hub.c:5899
#5: ffffffff8c944748 (tk_core.seq.seqcount){----}-{0:0}, at: timekeeping_get_delta kernel/time/timekeeping.c:254 [inline]
#5: ffffffff8c944748 (tk_core.seq.seqcount){----}-{0:0}, at: timekeeping_get_ns kernel/time/timekeeping.c:388 [inline]
#5: ffffffff8c944748 (tk_core.seq.seqcount){----}-{0:0}, at: ktime_get+0x7b/0x270 kernel/time/timekeeping.c:848
2 locks held by kworker/1:5/4334:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc9000464fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
5 locks held by kworker/u4:6/4356:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900047cfd00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: vti6_exit_batch_net+0xb3/0x410 net/ipv6/ip6_vti.c:1186
#4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
3 locks held by kworker/u4:15/4934:
1 lock held by syz.0.533/7082:
#0: ffff8880250da4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x13d/0xa60 block/bdev.c:832
2 locks held by syz.7.964/9805:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3618 Comm: syslogd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:unwind_next_frame+0x2e/0x20b0 arch/x86/kernel/unwind_orc.c:424
Code: 56 41 55 41 54 53 48 81 ec a0 00 00 00 48 89 fb 49 be 00 00 00 00 00 fc ff df 48 8d 6f 48 48 89 e8 48 c1 e8 03 48 89 44 24 28 <42> 80 3c 30 00 74 08 48 89 ef e8 33 ac 98 00 4c 8b 63 48 4c 8d 7b
RSP: 0018:ffffc90003257450 EFLAGS: 00000a02
RAX: 1ffff9200064aeae RBX: ffffc90003257528 RCX: 0000000080000000
RDX: dffffc0000000000 RSI: ffffffff81d0e81b RDI: ffffc90003257528
RBP: ffffc90003257570 R08: ffffc900032575f0 R09: 0000000000000000
R10: fffff5200064aeb1 R11: 1ffff9200064aeaf R12: ffff88807d5fbb80
R13: ffffc90003257940 R14: dffffc0000000000 R15: ffffc90003257528
FS: 00007f8235822c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f921ebb6ad8 CR3: 0000000018206000 CR4: 00000000003506e0
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:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:177 [inline]
slab_free_hook mm/slub.c:1729 [inline]
slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1755
slab_free mm/slub.c:3687 [inline]
__kmem_cache_free+0xb6/0x1f0 mm/slub.c:3700
skb_free_head net/core/skbuff.c:762 [inline]
skb_release_data+0x5db/0x7c0 net/core/skbuff.c:791
skb_release_all net/core/skbuff.c:856 [inline]
__kfree_skb net/core/skbuff.c:870 [inline]
consume_skb+0xa2/0x100 net/core/skbuff.c:1035
__unix_dgram_recvmsg+0xa06/0xd70 net/unix/af_unix.c:2531
sock_recvmsg_nosec net/socket.c:1022 [inline]
sock_recvmsg net/socket.c:1040 [inline]
sock_read_iter+0x2bf/0x370 net/socket.c:1121
call_read_iter include/linux/fs.h:2259 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x434/0x920 fs/read_write.c:470
ksys_read+0x143/0x240 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8235972407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffd38f7c930 EFLAGS: 00000202 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007f8235822c80 RCX: 00007f8235972407
RDX: 00000000000000ff RSI: 000055653b73f950 RDI: 0000000000000000
RBP: 000055653b73f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055653b73f989
R13: 0000000000000000 R14: 000055653b73f950 R15: 000055651e9ecd98