INFO: task syz.4.411:9284 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.411 state:D stack:22120 pid:9284 tgid:9232 ppid:7731 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:995 [inline]
open_last_lookups fs/namei.c:3894 [inline]
path_openat+0x8d7/0x3840 fs/namei.c:4131
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f365502f749
RSP: 002b:00007f3653275038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3655286090 RCX: 00007f365502f749
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f36550b3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3655286128 R14: 00007f3655286090 R15: 00007ffdabab63d8
INFO: task syz.4.411:9295 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.411 state:D stack:27000 pid:9295 tgid:9232 ppid:7731 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
inode_lock include/linux/fs.h:980 [inline]
open_last_lookups fs/namei.c:3892 [inline]
path_openat+0x8e6/0x3840 fs/namei.c:4131
do_filp_open+0x1fa/0x410 fs/namei.c:4161
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f365502f749
RSP: 002b:00007f3652e31038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f3655286270 RCX: 00007f365502f749
RDX: 000000000000275a RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f36550b3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3655286308 R14: 00007f3655286270 R15: 00007ffdabab63d8
INFO: task syz.4.411:9296 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.411 state:D stack:27112 pid:9296 tgid:9232 ppid:7731 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
__rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1466 [inline]
down_read+0x127/0x1f0 kernel/locking/rwsem.c:1539
inode_lock_shared include/linux/fs.h:995 [inline]
lookup_slow+0x46/0x70 fs/namei.c:1832
walk_component+0x2d2/0x400 fs/namei.c:2151
lookup_last fs/namei.c:2652 [inline]
path_lookupat+0x163/0x430 fs/namei.c:2676
filename_lookup+0x212/0x570 fs/namei.c:2705
user_path_at+0x3a/0x60 fs/namei.c:3215
do_fchmodat+0xef/0x200 fs/open.c:695
__do_sys_chmod fs/open.c:721 [inline]
__se_sys_chmod fs/open.c:719 [inline]
__x64_sys_chmod+0x62/0x70 fs/open.c:719
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f365502f749
RSP: 002b:00007f3652a0e038 EFLAGS: 00000246 ORIG_RAX: 000000000000005a
RAX: ffffffffffffffda RBX: 00007f3655286360 RCX: 00007f365502f749
RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000200000000140
RBP: 00007f36550b3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36552863f8 R14: 00007f3655286360 R15: 00007ffdabab63d8
Showing all locks held in the system:
6 locks held by kworker/u8:0/12:
1 lock held by khungtaskd/38:
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:4/68:
#0: ffff888060709938 ((wq_completion)loop9){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff888060709938 ((wq_completion)loop9){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000153fba0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000153fba0 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff888024661160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#2: ffff888024661160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0xf8/0x1060 drivers/block/loop.c:1951
2 locks held by kworker/u8:8/1141:
#0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90004887ba0 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90004887ba0 ((work_completion)(&(&kfence_timer)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
2 locks held by getty/5559:
#0: ffff88823bf340a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
4 locks held by kworker/u8:5/8823:
#0: ffff8881404ab138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff8881404ab138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000578fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000578fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffff88803c3960d0 (&type->s_umount_key#59){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
#3: ffff88806a834fe8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by syz.4.411/9235:
1 lock held by syz.4.411/9284:
#0: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline]
#0: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:3894 [inline]
#0: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0x8d7/0x3840 fs/namei.c:4131
2 locks held by syz.4.411/9295:
#0: ffff88803c396480 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock include/linux/fs.h:980 [inline]
#1: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: open_last_lookups fs/namei.c:3892 [inline]
#1: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: path_openat+0x8e6/0x3840 fs/namei.c:4131
1 lock held by syz.4.411/9296:
#0: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline]
#0: ffff88806a8353b8 (&type->i_mutex_dir_key#19){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
2 locks held by syz.7.438/9454:
#0: ffff88803c3960d0 (&type->s_umount_key#59){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88803c3960d0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff8880245a48c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
#1: ffff8880245a48c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2871
1 lock held by syz-executor/9474:
4 locks held by udevd/9664:
#0: ffff888022076ea8 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline]
#0: ffff888022076ea8 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:858
#1: ffff888022077078 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1045 [inline]
#1: ffff888022077078 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_update_page mm/filemap.c:2497 [inline]
#1: ffff888022077078 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_get_pages+0x772/0x1f00 mm/filemap.c:2661
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#2: ffffffff8d5aa880 (rcu_read_lock){....}-{1:3}, at: blk_mq_dispatch_queue_requests+0x552/0x800 block/blk-mq.c:2887
#3: ffff888024661160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#3: ffff888024661160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_queue_work drivers/block/loop.c:805 [inline]
#3: ffff888024661160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_queue_rq+0x23c/0xb00 drivers/block/loop.c:1891
1 lock held by udevd/9665:
11 locks held by syz.9.565/10746:
2 locks held by syz.9.565/10769:
1 lock held by syz.0.566/10750:
2 locks held by syz.1.567/10760:
2 locks held by udevadm/10768:
2 locks held by dhcpcd-run-hook/10772:
=============================================
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 10/25/2025
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:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 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: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: bat_events batadv_dat_purge
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4703 [inline]
RIP: 0010:__lock_acquire+0x72e/0xd20 kernel/locking/lockdep.c:5221
Code: 3e 8b 9f 58 0b 00 00 48 85 db 0f 84 81 00 00 00 83 fb 31 0f 83 e0 05 00 00 48 8d 04 9b 45 8b 66 20 48 8b 4c 24 10 8b 44 c1 f8 <44> 31 e0 25 00 60 00 00 31 c9 89 c2 f7 da 48 19 c9 49 09 cf 85 c0
RSP: 0018:ffffc900001177a8 EFLAGS: 00000087
RAX: 0000000000040b81 RBX: 0000000000000002 RCX: ffff88801b6a6560
RDX: 0000000000000008 RSI: ffff88801b6a65b0 RDI: ffff88801b6a5a00
RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81849131
R10: 0000000000000000 R11: fffffbfff1dac84f R12: 000000000002000b
R13: 0000000000000001 R14: ffff88801b6a65b0 R15: 9fc0020807cf187c
FS: 0000000000000000(0000) GS:ffff888126df6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd7259e0000 CR3: 000000000d3a6000 CR4: 00000000003526f0
Call Trace:
reacquire_held_locks+0x127/0x1d0 kernel/locking/lockdep.c:5385
__lock_release kernel/locking/lockdep.c:5574 [inline]
lock_release+0x1b4/0x3e0 kernel/locking/lockdep.c:5889
__local_bh_enable_ip+0x115/0x2e0 kernel/softirq.c:268
local_bh_enable include/linux/bottom_half.h:33 [inline]
spin_unlock_bh include/linux/spinlock_rt.h:111 [inline]
__batadv_dat_purge+0x344/0x400 net/batman-adv/distributed-arp-table.c:185
batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204
process_one_work kernel/workqueue.c:3263 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245