INFO: task syz-executor:4254 blocked for more than 144 seconds.
Not tainted 6.1.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:19576 pid:4254 ppid:1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x143f/0x4570 kernel/sched/core.c:6561
schedule+0xbf/0x180 kernel/sched/core.c:6637
wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191
sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739
sync_filesystem+0x16b/0x220 fs/sync.c:64
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7a/0xe0 fs/super.c:1470
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa6e/0x26a0 kernel/exit.c:871
do_group_exit+0x202/0x2b0 kernel/exit.c:1021
__do_sys_exit_group kernel/exit.c:1032 [inline]
__se_sys_exit_group kernel/exit.c:1030 [inline]
__x64_sys_exit_group+0x3b/0x40 kernel/exit.c:1030
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fdae6b8d169
RSP: 002b:00007ffcb20c8818 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007fdae6c0e0fe RCX: 00007fdae6b8d169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000010 R08: 00007ffcb20c65b6 R09: 00007ffcb20c9ad0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcb20c9ad0
R13: 00007fdae6c0e08c R14: 00005555687cd4a8 R15: 00007ffcb20caba0
INFO: task syz.0.293:5369 blocked for more than 144 seconds.
Not tainted 6.1.133-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.293 state:D stack:25224 pid:5369 ppid:4250 flags:0x00004006
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x143f/0x4570 kernel/sched/core.c:6561
schedule+0xbf/0x180 kernel/sched/core.c:6637
wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191
sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739
sync_filesystem+0x16b/0x220 fs/sync.c:64
generic_shutdown_super+0x6b/0x340 fs/super.c:474
kill_block_super+0x7a/0xe0 fs/super.c:1470
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:203
exit_task_work include/linux/task_work.h:39 [inline]
do_exit+0xa6e/0x26a0 kernel/exit.c:871
do_group_exit+0x202/0x2b0 kernel/exit.c:1021
get_signal+0x16cb/0x17a0 kernel/signal.c:2871
arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f51f19bfa25
RSP: 002b:00007f51f27b1f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f51f1ba5fa0 RCX: 00007f51f19bfa25
RDX: 00007f51f27b1fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f51f1a0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f51f1ba5fa0 R15: 00007ffdfe427df8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d32e910 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d32f110 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/27:
#0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510
2 locks held by getty/4007:
#0: ffff88803137e098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000325e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x54a/0x1620 drivers/tty/n_tty.c:2198
2 locks held by syz-executor/4254:
#0: ffff88802f13a0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
#1: ffff88802560e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
#1: ffff88802560e7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737
4 locks held by kworker/u4:6/4309:
3 locks held by kworker/u4:7/4314:
3 locks held by kworker/u4:14/4427:
2 locks held by kworker/0:12/4818:
#0: ffff888017c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
#1: ffffc90005ed7d20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
2 locks held by syz.0.293/5369:
#0: ffff8880566420e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
#1: ffff8880255f27d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
#1: ffff8880255f27d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737
5 locks held by kworker/u4:17/5415:
#0: ffff888017e16938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
#1: ffffc9001cc07d20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x806/0x1260 kernel/workqueue.c:2267
#2: ffffffff8e544110 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x166/0xd20 net/core/net_namespace.c:594
#3: ffffffff8e550c68 (rtnl_mutex){+.+.}-{3:3}, at: vti6_exit_batch_net+0xb0/0x410 net/ipv6/ip6_vti.c:1185
#4: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#4: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962
1 lock held by syz-executor/6866:
#0: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:323 [inline]
#0: ffffffff8d333d78 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x930 kernel/rcu/tree_exp.h:962
2 locks held by syz-executor/7116:
#0: ffff88807d2ba0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
#1: ffff8880256be7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline]
#1: ffff8880256be7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.133-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1ca/0x430 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+0xf88/0xfd0 kernel/hung_task.c:377
kthread+0x28d/0x320 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: 4314 Comm: kworker/u4:7 Not tainted 6.1.133-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: writeback wb_workfn (flush-7:6)
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:360 [inline]
RIP: 0010:unwind_next_frame+0xd73/0x2220 arch/x86/kernel/unwind_orc.c:539
Code: 03 00 00 4c 39 f0 0f 87 93 03 00 00 4c 89 ef e8 f3 1d 00 00 49 89 c6 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 30 80 3c 28 00 <48> 8b 5c 24 18 74 08 48 89 df e8 2e 19 a5 00 4c 89 33 48 8b 44 24
RSP: 0018:ffffc900044a69a0 EFLAGS: 00000246
RAX: 1ffff92000894d59 RBX: ffffc900044a8000 RCX: 1ffff92000894d50
RDX: 1ffffffff1e5c7fa RSI: 0000000000000000 RDI: ffffc900044a6f38
RBP: dffffc0000000000 R08: 0000000000000008 R09: ffffc900044a6b70
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffc900044a6a80
R13: ffffc900044a6f38 R14: ffffffff823aec0d R15: 1ffff92000894d51
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd2dcd762d8 CR3: 0000000078b0f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
__kasan_slab_alloc+0x65/0x70 mm/kasan/common.c:328
kasan_slab_alloc include/linux/kasan.h:201 [inline]
slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
slab_alloc_node mm/slub.c:3398 [inline]
slab_alloc mm/slub.c:3406 [inline]
__kmem_cache_alloc_lru mm/slub.c:3413 [inline]
kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422
kmem_cache_zalloc include/linux/slab.h:689 [inline]
ext4_init_io_end+0x25/0x120 fs/ext4/page-io.c:278
ext4_writepages+0xc8d/0x3de0 fs/ext4/inode.c:2803
do_writepages+0x3a2/0x670 mm/page-writeback.c:2491
__writeback_single_inode+0x15d/0x11e0 fs/fs-writeback.c:1612
writeback_sb_inodes+0xc2b/0x1b20 fs/fs-writeback.c:1903
wb_writeback+0x49d/0xe10 fs/fs-writeback.c:2077
wb_do_writeback fs/fs-writeback.c:2220 [inline]
wb_workfn+0x427/0x1020 fs/fs-writeback.c:2260
process_one_work+0x917/0x1260 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295