INFO: task kworker/u4:11:4370 blocked for more than 144 seconds.
Not tainted 5.15.185-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:11 state:D stack:22464 pid: 4370 ppid: 2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
rwsem_down_write_slowpath+0xc46/0x11f0 kernel/locking/rwsem.c:1165
f2fs_balance_fs+0x47d/0x660 fs/f2fs/segment.c:528
f2fs_write_inode+0x531/0x760 fs/f2fs/inode.c:738
write_inode fs/fs-writeback.c:1495 [inline]
__writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1705
writeback_sb_inodes+0x9fe/0x1610 fs/fs-writeback.c:1930
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2001
wb_writeback+0x455/0xb90 fs/fs-writeback.c:2106
wb_check_background_flush fs/fs-writeback.c:2172 [inline]
wb_do_writeback fs/fs-writeback.c:2260 [inline]
wb_workfn+0xb47/0xe60 fs/fs-writeback.c:2288
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
INFO: task syz.3.389:5919 blocked for more than 145 seconds.
Not tainted 5.15.185-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.389 state:D stack:25536 pid: 5919 ppid: 4177 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
rwsem_down_write_slowpath+0xc46/0x11f0 kernel/locking/rwsem.c:1165
inode_lock include/linux/fs.h:787 [inline]
f2fs_file_write_iter+0x1c9/0xae0 fs/f2fs/file.c:4346
call_write_iter include/linux/fs.h:2172 [inline]
new_sync_write fs/read_write.c:507 [inline]
vfs_write+0x712/0xd00 fs/read_write.c:594
ksys_write+0x14d/0x250 fs/read_write.c:647
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9d8620c929
RSP: 002b:00007f9d84032038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f9d86434160 RCX: 00007f9d8620c929
RDX: 0000000000000018 RSI: 0000200000000040 RDI: 0000000000000007
RBP: 00007f9d8628eb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9d86434160 R15: 00007ffd98fd1468
Showing all locks held in the system:
4 locks held by kworker/u4:0/9:
1 lock held by khungtaskd/27:
#0: ffffffff8c11bfa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by udevd/3547:
#0: ffff88801fc85918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by getty/3944:
#0: ffff88802bc3f098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc900021be2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
1 lock held by syz-executor/4168:
#0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#0: ffffffff8c120a28 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x320/0x6b0 kernel/rcu/tree_exp.h:845
2 locks held by kworker/1:5/4212:
4 locks held by kworker/u4:11/4370:
#0: ffff8881423c8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000324fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
#2: ffff88802b3f20e0 (&type->s_umount_key#54){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418
#3: ffff88807798d1b0 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x47d/0x660 fs/f2fs/segment.c:528
4 locks held by syz.3.389/5917:
3 locks held by syz.3.389/5919:
#0: ffff88802a3dc5f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2bf/0x370 fs/file.c:1058
#1: ffff88802b3f2460 (sb_writers#16){.+.+}-{0:0}, at: vfs_write+0x28a/0xd00 fs/read_write.c:590
#2: ffff88805eb61450 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline]
#2: ffff88805eb61450 (&sb->s_type->i_mutex_key#23){+.+.}-{3:3}, at: f2fs_file_write_iter+0x1c9/0xae0 fs/f2fs/file.c:4346
2 locks held by syz-executor/6046:
#0: ffff88801fc87518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff88801fea3468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366
2 locks held by kworker/0:17/6902:
#0: ffff888016872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1
#1: ffffc9000399fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285
3 locks held by syz.5.628/6939:
#0: ffffffff8c6068e8 (uuid_mutex){+.+.}-{3:3}, at: btrfs_mount_root+0x262/0x8c0 fs/btrfs/super.c:1708
#1: ffff88801fc85918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#2: ffff88801fea0468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
2 locks held by syz.4.631/6950:
#0: ffff88801fc83d18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
#1: ffff8881479a5468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xe0f/0xe50 kernel/hung_task.c:369
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5917 Comm: syz.3.389 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:stack_trace_consume_entry+0xcc/0x270 kernel/stacktrace.c:93
Code: ff 48 89 74 24 08 49 89 d4 4c 89 04 24 4c 89 cb e8 c9 d4 56 00 49 89 d9 4c 8b 04 24 4c 89 e2 4c 89 ff 48 8b 74 24 08 48 8b 1f <45> 8d 79 01 0f b6 44 15 00 84 c0 0f 85 35 01 00 00 45 89 38 4e 8d
RSP: 0018:ffffc900021a65f8 EFLAGS: 00000246
RAX: 1ffff92000434ce0 RBX: ffffc900021a6780 RCX: 0000000080000001
RDX: dffffc0000000000 RSI: ffffffff836f29f3 RDI: ffffc900021a6700
RBP: 1ffff92000434ce2 R08: ffffc900021a6710 R09: 000000000000000d
R10: fffff52000434cd5 R11: 1ffff92000434cd3 R12: 0000000000000000
R13: 1ffff92000434ce1 R14: ffffc900021a6708 R15: 1ffff92000434ce1
FS: 00007f9d840536c0(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000056c46000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
arch_stack_walk+0x100/0x140 arch/x86/kernel/stacktrace.c:27
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
slab_alloc_node mm/slub.c:3220 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0x100/0x290 mm/slub.c:3233
mempool_alloc+0x18f/0x4e0 mm/mempool.c:393
bio_alloc_bioset+0x124/0x870 block/bio.c:466
f2fs_grab_read_bio+0xa7/0x730 fs/f2fs/data.c:990
f2fs_submit_page_read+0xaf/0x2b0 fs/f2fs/data.c:1035
f2fs_get_read_data_page+0x390/0x560 fs/f2fs/data.c:1224
gc_data_segment fs/f2fs/gc.c:1504 [inline]
do_garbage_collect+0x3dfb/0x60a0 fs/f2fs/gc.c:1671
f2fs_gc+0x8a9/0x1900 fs/f2fs/gc.c:1765
f2fs_balance_fs+0x491/0x660 fs/f2fs/segment.c:529
f2fs_map_blocks+0x2976/0x3310 fs/f2fs/data.c:1746
expand_inode_data+0x4a0/0x6e0 fs/f2fs/file.c:1716
f2fs_fallocate+0x423/0x8c0 fs/f2fs/file.c:1818
vfs_fallocate+0x587/0x6f0 fs/open.c:308
ioctl_preallocate fs/ioctl.c:294 [inline]
file_ioctl fs/ioctl.c:-1 [inline]
do_vfs_ioctl+0x1b70/0x1de0 fs/ioctl.c:853
__do_sys_ioctl fs/ioctl.c:872 [inline]
__se_sys_ioctl+0x83/0x170 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9d8620c929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9d84053038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9d86434080 RCX: 00007f9d8620c929
RDX: 0000200000000000 RSI: 0000000040305828 RDI: 0000000000000007
RBP: 00007f9d8628eb39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f9d86434080 R15: 00007ffd98fd1468
vkms_vblank_simulate: vblank timer overrun