INFO: task syz-executor:11572 blocked for more than 142 seconds.
Tainted: G L syzkaller #0
Blocked by coredump.
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:22416 pid:11572 tgid:11572 ppid:1 task_flags:0x40014c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1840/0x57a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
wb_wait_for_completion+0x3b2/0x700 fs/fs-writeback.c:227
sync_inodes_sb+0x224/0xbf0 fs/fs-writeback.c:2944
sync_filesystem+0x17a/0x230 fs/sync.c:64
generic_shutdown_super+0x77/0x2d0 fs/super.c:625
kill_block_super+0x44/0x90 fs/super.c:1725
ext4_kill_sb+0x68/0xb0 fs/ext4/super.c:7492
deactivate_locked_super+0xbc/0x130 fs/super.c:476
cleanup_mnt+0x3d3/0x460 fs/namespace.c:1312
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:976
do_group_exit+0x22d/0x2f0 kernel/exit.c:1119
__do_sys_exit_group kernel/exit.c:1130 [inline]
__se_sys_exit_group kernel/exit.c:1128 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1128
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc5b019ce59
RSP: 002b:00007ffe2576e918 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fc5b02321ef RCX: 00007fc5b019ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 000000000000000c R08: 0000000000000000 R09: 00007fc5b02321ca
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe2576fbd0
R13: 00007fc5b02321ca R14: 00000000000ab00b R15: 00007ffe25770ca0
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8e95c780 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by udevd/4993:
#0: ffff8880b873b0e0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2d/0x160 kernel/sched/core.c:652
1 lock held by dhcpcd/5288:
#0: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x464/0x19e0 net/ipv4/devinet.c:978
2 locks held by getty/5385:
#0: ffff8880367c70a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1380 drivers/tty/n_tty.c:2211
6 locks held by kworker/0:6/5790:
5 locks held by kworker/u8:18/6735:
2 locks held by syz-executor/11572:
#0: ffff88807ae6a0d8 (&type->s_umount_key#33){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff88807ae6a0d8 (&type->s_umount_key#33){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff88807ae6a0d8 (&type->s_umount_key#33){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
#1: ffff888026820810 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:396 [inline]
#1: ffff888026820810 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x208/0xbf0 fs/fs-writeback.c:2942
2 locks held by syz-executor/12810:
#0: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3442
#1: ffffffff8e962aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline]
#1: ffffffff8e962aa8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961
7 locks held by syz-executor/15248:
#0: ffff888034848410 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline]
#0: ffff888034848410 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22b/0xba0 fs/read_write.c:684
#1: ffff888031cd5480 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d8/0x540 fs/kernfs/file.c:343
#2: ffff888029452b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888029452b48 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x22b/0x540 fs/kernfs/file.c:344
#3: ffffffff8f64dc40 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd6/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff88802b6ab128 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff88802b6ab128 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff88802b6ab128 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb9/0x880 drivers/base/dd.c:1372
#5: ffff88802b6a9258 (&devlink->lock_key#16){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1799
#6: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#6: ffffffff8fdc06c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2162
2 locks held by syz.5.1743/15609:
#0: ffff88801bafd2a0 (&root->kernfs_supers_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3f/0x140 fs/kernfs/dir.c:1792
#1: ffff88801bafd180 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x4e/0x140 fs/kernfs/dir.c:1793
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd7/0x1030 kernel/hung_task.c:561
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 6735 Comm: kworker/u8:18 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: writeback wb_workfn (flush-7:8)
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
RIP: 0010:lock_release+0x25e/0x3c0 kernel/locking/lockdep.c:5891
Code: 89 c5 7f d0 4c 89 ff 4c 89 f6 48 8b 54 24 18 e8 28 2f 00 00 48 8b 5c 24 08 48 c7 c7 10 3c 21 8e e8 87 ed 00 0a b8 ff ff ff ff <65> 0f c1 05 2a 40 95 11 83 f8 01 75 2e 9c 58 a9 00 02 00 00 75 42
RSP: 0018:ffffc90003606338 EFLAGS: 00000046
RAX: 00000000ffffffff RBX: 0000000000000202 RCX: 0000000000000046
RDX: 0000000000000004 RSI: ffffffff8e213c10 RDI: ffffffff8c2899a0
RBP: ffff888030ab4a30 R08: ffffc90003607e18 R09: ffffc90003606498
R10: dffffc0000000000 R11: fffff520006c0c95 R12: 0000000000000004
R13: 0000000000000004 R14: ffffffff8e95c780 R15: ffff888030ab3e00
FS: 0000000000000000(0000) GS:ffff8881252b9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000033c0 CR3: 0000000027b3b000 CR4: 0000000000350ef0
Call Trace:
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:869 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
slab_free mm/slub.c:6251 [inline]
kfree+0x1c5/0x640 mm/slub.c:6566
ext4_free_ext_path fs/ext4/extents.c:127 [inline]
ext4_find_extent+0x971/0xcd0 fs/ext4/extents.c:966
ext4_ext_map_blocks+0x2ac/0x5850 fs/ext4/extents.c:4286
ext4_map_create_blocks+0x116/0x530 fs/ext4/inode.c:631
ext4_map_blocks+0x7e4/0x1240 fs/ext4/inode.c:824
mpage_map_one_extent fs/ext4/inode.c:2396 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2490 [inline]
ext4_do_writepages+0x23d3/0x47a0 fs/ext4/inode.c:2948
ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3042
do_writepages+0x338/0x560 mm/page-writeback.c:2571
__writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1764
writeback_sb_inodes+0x9de/0x1b00 fs/fs-writeback.c:2056
wb_writeback+0x41c/0xad0 fs/fs-writeback.c:2241
wb_do_writeback fs/fs-writeback.c:2388 [inline]
wb_workfn+0x3f8/0xf10 fs/fs-writeback.c:2428
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3397
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3478
kthread+0x389/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245