INFO: task kworker/u8:16:6130 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:16 state:D stack:20264 pid:6130 tgid:6130 ppid:2 task_flags:0x4208060 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
context_switch kernel/sched/core.c:5357 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
__schedule_loop kernel/sched/core.c:7043 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
rt_mutex_slowlock_block+0x5ba/0x6d0 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2b1/0x6e0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline]
mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:132
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x6f4/0x1000 fs/fs-writeback.c:1745
writeback_sb_inodes+0x6b7/0xf60 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+0xaf4/0xf00 fs/fs-writeback.c:2343
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 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/38:
#0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d9a8d80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:5/156:
3 locks held by kworker/u8:6/990:
#0: ffff88803ca9c938 ((wq_completion)loop2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88803ca9c938 ((wq_completion)loop2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000487fbc0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000487fbc0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88802471c160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#2: ffff88802471c160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0xf8/0x1060 drivers/block/loop.c:1947
2 locks held by getty/5594:
#0: ffff88823bf2a8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:3/5840:
#0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019898538 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90004a2fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90004a2fbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd3578 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
2 locks held by udevd/6004:
6 locks held by kworker/u8:11/6008:
1 lock held by udevd/6041:
3 locks held by kworker/u8:12/6126:
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888019881138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000a537bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000a537bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd3578 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
4 locks held by kworker/u8:16/6130:
#0: ffff888142ae2138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff888142ae2138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc9000b52fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc9000b52fbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffff88805fae40d0 (&type->s_umount_key#57){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88805d2df7a8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
2 locks held by kworker/u8:8/10082:
3 locks held by kworker/u8:10/10084:
#0: ffff88802fecb938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
#0: ffff88802fecb938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
#1: ffffc90004047bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
#1: ffffc90004047bc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
#2: ffffffff8ecd3578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8ecd3578 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x119/0x15a0 net/ipv6/addrconf.c:4194
4 locks held by syz.1.1200/13712:
2 locks held by syz-executor/14707:
1 lock held by syz-executor/14972:
#0: ffffffff8ecd3578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8ecd3578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8ecd3578 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056
4 locks held by syz.2.1383/15069:
2 locks held by syz.2.1383/15073:
#0: ffff888032d3a488 (sb_writers#32){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
#1: ffff88805ee34e58 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: inode_lock include/linux/fs.h:870 [inline]
#1: ffff88805ee34e58 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: open_last_lookups fs/namei.c:3804 [inline]
#1: ffff88805ee34e58 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4043
8 locks held by syz.2.1383/15080:
2 locks held by syz.2.1383/15081:
#0: ffff888035a2f728 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x253/0x320 fs/file.c:1232
#1: ffff88805ee34e58 (&type->i_mutex_dir_key#15){++++}-{4:4}, at: iterate_dir+0x29e/0x580 fs/readdir.c:101
2 locks held by syz.8.1385/15076:
1 lock held by sed/15079:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
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+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x439/0x7d0 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: 15080 Comm: syz.2.1383 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:__bfs kernel/locking/lockdep.c:1753 [inline]
RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1860 [inline]
RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2796 [inline]
RIP: 0010:check_prev_add kernel/locking/lockdep.c:3169 [inline]
RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3284 [inline]
RIP: 0010:validate_chain+0xe7d/0x2140 kernel/locking/lockdep.c:3908
Code: 00 00 0f 83 89 01 00 00 4e 8b 2c fd c0 67 fe 94 ff c0 25 ff 0f 00 00 89 05 e0 8f 62 13 4d 85 ed 0f 84 a7 01 00 00 49 8b 45 10 <48> 85 c0 0f 84 bb 0b 00 00 8b 0d cc 8f 62 13 39 48 5c 0f 84 6e ff
RSP: 0018:ffffc900048ae228 EFLAGS: 00000082
RAX: ffffffff92a904b0 RBX: 00000000000003cd RCX: ffffffff95bca558
RDX: 0000000000000008 RSI: 00000000000003cd RDI: ffff88802d6ed940
RBP: ffffffff92a74f30 R08: ffffc900048ae1f0 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff819c7440 R12: ffffffff9598b368
R13: ffffffff95bca558 R14: ffff88802d6ee5a0 R15: 00000000000002df
FS: 00007f1803fc56c0(0000) GS:ffff8881268bd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f00946dd000 CR3: 0000000054cf2000 CR4: 00000000003526f0
Call Trace:
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
_raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378
raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
raw_spin_rq_lock kernel/sched/sched.h:1519 [inline]
task_rq_lock+0xbc/0x470 kernel/sched/core.c:736
__set_cpus_allowed_ptr kernel/sched/core.c:3182 [inline]
migrate_enable+0x12a/0x3c0 kernel/sched/core.c:2433
rt_spin_unlock+0x1b/0x80 kernel/locking/spinlock_rt.c:81
spin_unlock_irq include/linux/spinlock_rt.h:116 [inline]
loop_queue_work drivers/block/loop.c:863 [inline]
loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1887
__blk_mq_issue_directly block/blk-mq.c:2695 [inline]
blk_mq_request_issue_directly+0x3c4/0x710 block/blk-mq.c:2782
blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2803
blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2878
blk_mq_flush_plug_list+0x432/0x550 block/blk-mq.c:2961
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
blk_finish_plug block/blk-core.c:1247 [inline]
__submit_bio+0x2d3/0x5a0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x4f2/0xbb0 block/blk-core.c:751
submit_bh fs/buffer.c:2829 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2447
filemap_read_folio+0x117/0x380 mm/filemap.c:2413
do_read_cache_folio+0x2ba/0x560 mm/filemap.c:3957
do_read_cache_page mm/filemap.c:4023 [inline]
read_cache_page+0x5d/0x170 mm/filemap.c:4032
read_mapping_page include/linux/pagemap.h:985 [inline]
__hfs_bnode_create+0x4a1/0x810 fs/hfsplus/bnode.c:538
hfsplus_bnode_find+0x224/0xd20 fs/hfsplus/bnode.c:584
hfsplus_brec_find+0x15c/0x500 fs/hfsplus/bfind.c:172
hfsplus_attr_exists+0x163/0x1d0 fs/hfsplus/attributes.c:182
__hfsplus_setxattr+0x35f/0x1fb0 fs/hfsplus/xattr.c:340
hfsplus_initxattrs+0x1ae/0x280 fs/hfsplus/xattr_security.c:59
security_inode_init_security+0x29d/0x3f0 security/security.c:1852
hfsplus_mknod+0x1a9/0x290 fs/hfsplus/dir.c:498
lookup_open fs/namei.c:3708 [inline]
open_last_lookups fs/namei.c:3807 [inline]
path_openat+0x1500/0x3840 fs/namei.c:4043
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
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: 0033:0x7f1805d7eba9
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:00007f1803fc5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1805fc6090 RCX: 00007f1805d7eba9
RDX: 00000000000026e1 RSI: 00002000000000c0 RDI: ffffffffffffff9c
RBP: 00007f1805e01e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1805fc6128 R14: 00007f1805fc6090 R15: 00007ffd190bd398