INFO: task syz.3.147:6819 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.147 state:D stack:25768 pid:6819 tgid:6816 ppid:5799 task_flags:0x400140 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
__super_lock fs/super.c:59 [inline]
super_lock+0x2a9/0x3b0 fs/super.c:121
__iterate_supers+0x126/0x290 fs/super.c:922
ksys_sync+0x94/0x150 fs/sync.c:102
__ia32_sys_sync+0xe/0x20 fs/sync.c:113
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: 0033:0x7fd0b8c6f6c9
RSP: 002b:00007fd0b6ece038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd0b8ec5fa0 RCX: 00007fd0b8c6f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd0b8ec5fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd0b8ec6038 R14: 00007fd0b8ec5fa0 R15: 00007ffc0c3c4fc8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/1:1/44:
3 locks held by kworker/u8:4/60:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc9000126fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc9000126fba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
2 locks held by kworker/u8:5/153:
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff69938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90003a87ba0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90003a87ba0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
6 locks held by kworker/u8:7/3119:
2 locks held by dhcpcd/5461:
#0: ffff888032314920 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: netlink_dump+0xbd/0xe90 net/netlink/af_netlink.c:2269
#1: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6819
2 locks held by getty/5554:
#0: ffff88823bf3c8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222
3 locks held by syz-executor/5798:
5 locks held by syz-executor/5801:
1 lock held by udevd/5854:
#0: ffff888022299568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline]
#0: ffff888022299568 (&sb->s_type->i_mutex_key#7){++++}-{4:4}, at: blkdev_read_iter+0x2ff/0x440 block/fops.c:858
2 locks held by kworker/u8:10/6022:
1 lock held by syz.3.147/6819:
#0: ffff88803147e0d0 (&type->s_umount_key#76){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88803147e0d0 (&type->s_umount_key#76){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
7 locks held by syz-executor/7486:
#0: ffff888010cf6480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline]
#0: ffff888010cf6480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88806e94d078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888026a9dd28 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888026a9dd28 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e0f3fd8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x12c/0x6f0 drivers/net/netdevsim/bus.c:184
#4: ffff8880386bf0d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff8880386bf0d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006
#5: ffff8880386bc300 (&devlink->lock_key#9){+.+.}-{4:4}, at: nsim_drv_probe+0xc2/0xba0 drivers/net/netdevsim/dev.c:1582
#6: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#6: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2142
1 lock held by syz-executor/7487:
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline]
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3436
4 locks held by syz-executor/7686:
#0: ffff888010cf6480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3111 [inline]
#0: ffff888010cf6480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff88804d003078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888026a9de18 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888026a9de18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8e0f3fd8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
1 lock held by syz-executor/7845:
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
1 lock held by syz-executor/7919:
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37d/0x1df0 drivers/net/tun.c:3078
1 lock held by syz-executor/7921:
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x37d/0x1df0 drivers/net/tun.c:3078
2 locks held by syz.5.310/7995:
#0: ffff88805d4800d0 (&type->s_umount_key#54/1){+.+.}-{4:4}, at: alloc_super+0x1ba/0x9a0 fs/super.c:344
#1: ffffffff8d4529f8 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5211 [inline]
#1: ffffffff8d4529f8 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0x9f4/0x1b70 kernel/workqueue.c:5766
1 lock held by syz-executor/7997:
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#0: ffffffff8e863238 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x3b0/0x18b0 net/ipv4/devinet.c:978
=============================================
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 10/02/2025
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: 5801 Comm: syz-executor Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline]
RIP: 0010:raw_atomic_try_cmpxchg include/linux/atomic/atomic-arch-fallback.h:2130 [inline]
RIP: 0010:raw_atomic_fetch_add_unless include/linux/atomic/atomic-arch-fallback.h:2431 [inline]
RIP: 0010:raw_atomic_add_unless include/linux/atomic/atomic-arch-fallback.h:2456 [inline]
RIP: 0010:atomic_add_unless include/linux/atomic/atomic-instrumented.h:1518 [inline]
RIP: 0010:iput+0x1b2/0xc50 fs/inode.c:1942
Code: 00 00 41 8b 1c 24 bf 01 00 00 00 89 de e8 a6 8b 8a ff 83 fb 01 74 46 4c 89 f5 4d 89 ee 8d 4b ff 31 f6 89 d8 f0 41 0f b1 0c 24 <41> 0f 95 c5 40 0f 94 c6 89 c3 bf 02 00 00 00 e8 1a 8a 8a ff 45 84
RSP: 0018:ffffc90004cd7848 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000002 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff88805eb92600 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed100bd72507 R12: ffff88805eb92830
R13: dffffc0000000000 R14: dffffc0000000000 R15: 1ffffffff1dac7ec
FS: 000055556c80f500(0000) GS:ffff888126df9000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1693386000 CR3: 0000000027868000 CR4: 00000000003526f0
Call Trace:
f2fs_sync_inode_meta fs/f2fs/checkpoint.c:1157 [inline]
block_operations fs/f2fs/checkpoint.c:1263 [inline]
f2fs_write_checkpoint+0xb5f/0x2440 fs/f2fs/checkpoint.c:1678
kill_f2fs_super+0x2cc/0x6d0 fs/f2fs/super.c:5448
deactivate_locked_super+0xbc/0x130 fs/super.c:473
cleanup_mnt+0x425/0x4c0 fs/namespace.c:1327
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xe9/0x130 kernel/entry/common.c:43
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0xfa0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4086d909f7
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc75fd7dc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f4086e11d7d RCX: 00007f4086d909f7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc75fd7e80
RBP: 00007ffc75fd7e80 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc75fd8f10
R13: 00007f4086e11d7d R14: 000000000001ffe7 R15: 00007ffc75fd8f50