INFO: task kworker/u8:29:8887 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:29 state:D stack:21848 pid:8887 tgid:8887 ppid:2 task_flags:0x4248160 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:9)
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7058
schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
___down_common kernel/locking/semaphore.c:268 [inline]
__down_common+0x319/0x6a0 kernel/locking/semaphore.c:293
down+0x80/0xd0 kernel/locking/semaphore.c:100
xfs_buf_lock+0x15d/0x4d0 fs/xfs/xfs_buf.c:996
xfs_buf_find_lock+0x42/0x4c0 fs/xfs/xfs_buf.c:422
xfs_buf_lookup fs/xfs/xfs_buf.c:475 [inline]
xfs_buf_get_map+0x10b7/0x1860 fs/xfs/xfs_buf.c:597
xfs_buf_read_map+0x82/0xa50 fs/xfs/xfs_buf.c:702
xfs_trans_read_buf_map+0x1d7/0x8e0 fs/xfs/xfs_trans_buf.c:304
xfs_trans_read_buf fs/xfs/xfs_trans.h:210 [inline]
xfs_read_agf+0x281/0x5c0 fs/xfs/libxfs/xfs_alloc.c:3376
xfs_alloc_read_agf+0x17c/0xb70 fs/xfs/libxfs/xfs_alloc.c:3411
xfs_alloc_fix_freelist+0x60a/0x1300 fs/xfs/libxfs/xfs_alloc.c:2875
xfs_alloc_vextent_prepare_ag+0xdb/0x610 fs/xfs/libxfs/xfs_alloc.c:3566
xfs_alloc_vextent_iterate_ags+0x140/0x940 fs/xfs/libxfs/xfs_alloc.c:3750
xfs_alloc_vextent_start_ag+0x388/0x850 fs/xfs/libxfs/xfs_alloc.c:3839
xfs_bmap_btalloc_best_length fs/xfs/libxfs/xfs_bmap.c:3627 [inline]
xfs_bmap_btalloc fs/xfs/libxfs/xfs_bmap.c:3672 [inline]
xfs_bmapi_allocate+0x188e/0x2e00 fs/xfs/libxfs/xfs_bmap.c:3947
xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4456 [inline]
xfs_bmapi_convert_delalloc+0x7e2/0x1430 fs/xfs/libxfs/xfs_bmap.c:4512
xfs_map_blocks fs/xfs/xfs_aops.c:445 [inline]
xfs_writeback_range+0x674/0xf70 fs/xfs/xfs_aops.c:489
iomap_writeback_range fs/iomap/buffered-io.c:1585 [inline]
iomap_writeback_folio+0xe75/0x1c80 fs/iomap/buffered-io.c:1710
iomap_writepages+0x162/0x2d0 fs/iomap/buffered-io.c:1762
xfs_vm_writepages+0x296/0x310 fs/xfs/xfs_aops.c:701
do_writepages+0x32e/0x550 mm/page-writeback.c:2634
__writeback_single_inode+0x145/0xff0 fs/fs-writeback.c:1680
writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
wb_do_writeback fs/fs-writeback.c:2315 [inline]
wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Showing all locks held in the system:
1 lock held by khungtaskd/31:
#0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5617:
#0: ffff88814d2050a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
5 locks held by kworker/u8:11/6278:
5 locks held by kworker/u8:29/8887:
#0: ffff88801ca95948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88801ca95948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000b3c7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000b3c7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88807917a0e0 (&type->s_umount_key#73){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88807917a618 (sb_internal#3){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x980 fs/xfs/xfs_trans.c:256
#4: ffff8880510227d8 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4391 [inline]
#4: ffff8880510227d8 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_bmapi_convert_delalloc+0x32c/0x1430 fs/xfs/libxfs/xfs_bmap.c:4512
4 locks held by syz.9.2840/18632:
#0: ffff88807917a428 (sb_writers#21){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
#1: ffff8880510212b0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
#1: ffff8880510212b0 (&sb->s_type->i_mutex_key#27){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320
#2: ffff88807917a618 (sb_internal#3){.+.+}-{0:0}, at: xfs_trans_alloc+0xd7/0x980 fs/xfs/xfs_trans.c:256
#3: ffff888051021098 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_trans_alloc_inode+0x161/0x4a0 fs/xfs/xfs_trans.c:1081
2 locks held by syz-executor/18781:
#0: ffffffff8e88e628 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline]
#0: ffffffff8e88e628 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x44a/0x690 block/bio.c:1764
#1: ffffffff8e13f880 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815
3 locks held by kworker/u8:6/20265:
2 locks held by syz.8.3335/20523:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
watchdog+0xf93/0xfe0 kernel/hung_task.c:491
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
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: 20523 Comm: syz.8.3335 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rb_erase_cached include/linux/rbtree.h:124 [inline]
RIP: 0010:timerqueue_del+0x85/0x100 lib/timerqueue.c:57
Code: 89 e7 49 c1 ef 03 43 80 3c 2f 00 74 08 4c 89 e7 e8 50 37 ad f6 4d 39 34 24 74 07 e8 f5 c5 49 f6 eb 26 e8 ee c5 49 f6 4c 89 f7 a6 81 ff ff 43 80 3c 2f 00 74 0e 4c 89 e7 49 89 c7 e8 14 38 ad
RSP: 0018:ffffc90000007d08 EFLAGS: 00000006
RAX: ffffffff8b75e862 RBX: ffff8880b8627c50 RCX: ffff8880782e9e00
RDX: 0000000000010000 RSI: ffff88802feb7340 RDI: ffff88802feb7340
RBP: 1ffff11005fd6e68 R08: ffffffff8fa39637 R09: 1ffffffff1f472c6
R10: dffffc0000000000 R11: fffffbfff1f472c7 R12: ffff8880b8627c58
R13: dffffc0000000000 R14: ffff88802feb7340 R15: 1ffff110170c4f8b
FS: 00007f3496cc26c0(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3495d716c0 CR3: 00000000a31fe000 CR4: 0000000000350ef0
Call Trace:
__remove_hrtimer kernel/time/hrtimer.c:1121 [inline]
__run_hrtimer kernel/time/hrtimer.c:1741 [inline]
__hrtimer_run_queues+0x364/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline]
RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449
Code: 85 32 01 00 00 e8 11 87 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 00 87 1f 00 eb 06 e8 f9 86 1f 00 fb 48 c7 c7 c0 e1 12 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 35
RSP: 0018:ffffc9000417f460 EFLAGS: 00000287
RAX: ffffffff81a02757 RBX: ffffffff81a02614 RCX: 0000000000080000
RDX: ffffc9001551d000 RSI: 0000000000047fec RDI: ffffffff8e12e1c0
RBP: ffffc9000417f570 R08: ffffffff8fa39637 R09: 1ffffffff1f472c6
R10: dffffc0000000000 R11: fffffbfff1f472c7 R12: dffffc0000000000
R13: 1ffff9200082fe90 R14: 0000000000000200 R15: 0000000000000015
_printk+0xcf/0x120 kernel/printk/printk.c:2475
parse_rock_ridge_inode_internal+0x10f9/0x2460 fs/isofs/rock.c:377
parse_rock_ridge_inode+0x4c/0x170 fs/isofs/rock.c:677
isofs_read_inode fs/isofs/inode.c:1408 [inline]
__isofs_iget+0x137e/0x20a0 fs/isofs/inode.c:1519
isofs_iget fs/isofs/isofs.h:135 [inline]
isofs_fill_super+0x14c0/0x2340 fs/isofs/inode.c:864
get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
vfs_get_tree+0x92/0x2b0 fs/super.c:1815
do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
do_mount fs/namespace.c:4136 [inline]
__do_sys_mount fs/namespace.c:4347 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3495d9038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007f3496cc1e68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f3496cc1ef0 RCX: 00007f3495d9038a
RDX: 0000200000000500 RSI: 0000200000000540 RDI: 00007f3496cc1eb0
RBP: 0000200000000500 R08: 00007f3496cc1ef0 R09: 0000000000000001
R10: 0000000000000001 R11: 0000000000000246 R12: 0000200000000540
R13: 00007f3496cc1eb0 R14: 00000000000004f8 R15: 0000200000000580