INFO: task syz.4.375:7432 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.375 state:D stack:28200 pid:7432 tgid:7430 ppid:5592 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x1681/0x54c0 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline]
__rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779
rt_mutex_slowlock+0xbd/0x170 kernel/locking/rtmutex.c:1819
__rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline]
rwbase_write_lock+0x14d/0x730 kernel/locking/rwbase_rt.c:245
inode_lock include/linux/fs.h:1029 [inline]
open_last_lookups fs/namei.c:4608 [inline]
path_openat+0xb5e/0x38a0 fs/namei.c:4855
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6ae324cdd9
RSP: 002b:00007f6ae1485028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6ae34c6090 RCX: 00007f6ae324cdd9
RDX: 00000000000c21c2 RSI: 0000200000000540 RDI: ffffffffffffff9c
RBP: 00007f6ae32e2d69 R08: 0000000000000000 R09: 0000000000000000
R10: 9c37611dc13d0db7 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6ae34c6128 R14: 00007f6ae34c6090 R15: 00007fff63fbf5a8
INFO: task syz.4.375:7434 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.375 state:D stack:25592 pid:7434 tgid:7430 ppid:5592 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x1681/0x54c0 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline]
__rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779
__rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114
rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
__down_read kernel/locking/rwsem.c:1496 [inline]
down_read+0x132/0x200 kernel/locking/rwsem.c:1570
inode_lock_shared include/linux/fs.h:1044 [inline]
lookup_slow+0x46/0x70 fs/namei.c:1931
walk_component fs/namei.c:2278 [inline]
lookup_last fs/namei.c:2785 [inline]
path_lookupat+0x3f5/0x8c0 fs/namei.c:2809
filename_lookup+0x256/0x5d0 fs/namei.c:2838
kern_path+0x3d/0x150 fs/namei.c:3044
lookup_bdev block/bdev.c:1213 [inline]
bdev_file_open_by_path+0xd5/0x480 block/bdev.c:1086
btrfs_scan_one_device+0xa8/0x680 fs/btrfs/volumes.c:1478
btrfs_control_ioctl+0x22b/0x360 fs/btrfs/super.c:2252
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xff/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6ae324cdd9
RSP: 002b:00007f6ae1041028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f6ae34c6270 RCX: 00007f6ae324cdd9
RDX: 0000200000000000 RSI: 0000000050009404 RDI: 0000000000000009
RBP: 00007f6ae32e2d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6ae34c6308 R14: 00007f6ae34c6270 R15: 00007fff63fbf5a8
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:2/43:
3 locks held by kworker/u8:6/87:
#0: ffff88803182d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88803182d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc900015afc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc900015afc40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8f355e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f355e78 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206
3 locks held by kworker/u8:7/774:
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc90004c1fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc90004c1fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8f355e78 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
5 locks held by kworker/u8:11/3313:
6 locks held by kworker/u8:14/4271:
#0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline]
#0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385
#1: ffffc9000f167c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline]
#1: ffffc9000f167c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385
#2: ffffffff8f347140 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffff888060d3d160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#3: ffff888060d3d160 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:124 [inline]
#3: ffff888060d3d160 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x129/0x420 net/devlink/core.c:555
#4: ffff88802b5e2310 (&devlink->lock_key#13){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:292 [inline]
#4: ffff88802b5e2310 (&devlink->lock_key#13){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:125 [inline]
#4: ffff88802b5e2310 (&devlink->lock_key#13){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x142/0x420 net/devlink/core.c:555
#5: ffffffff8f355e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#5: ffffffff8f355e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_dev_lock+0x257/0x2f0 net/core/dev.c:2162
2 locks held by getty/5351:
#0: ffff888031d280a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cb62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz.4.375/7431:
1 lock held by syz.4.375/7432:
#0: ffff888061bd1510 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline]
#0: ffff888061bd1510 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: open_last_lookups fs/namei.c:4608 [inline]
#0: ffff888061bd1510 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: path_openat+0xb5e/0x38a0 fs/namei.c:4855
2 locks held by syz.4.375/7434:
#0: ffffffff8e5e26d8 (uuid_mutex){+.+.}-{4:4}, at: btrfs_control_ioctl+0x21d/0x360 fs/btrfs/super.c:2247
#1: ffff888061bd1510 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:1044 [inline]
#1: ffff888061bd1510 (&type->i_mutex_dir_key#22){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1931
7 locks held by syz-executor/8213:
#0: ffff888032856480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline]
#0: ffff888032856480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#1: ffff88806171a078 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff8880290f8788 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880290f8788 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8ebcea78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234
#4: ffff888029fa4160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
#4: ffff888029fa4160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1174 [inline]
#4: ffff888029fa4160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x870 drivers/base/dd.c:1372
#5: ffff88805bea6310 (&devlink->lock_key#10){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1799
#6: ffffffff8dfce2f0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
4 locks held by syz-executor/8215:
#0: ffff888032856480 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2724 [inline]
#0: ffff888032856480 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x22d/0xba0 fs/read_write.c:684
#1: ffff888024e25c78 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff8880290f8878 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff8880290f8878 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8ebcea78 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: new_device_store+0x13c/0x710 drivers/net/netdevsim/bus.c:184
2 locks held by syz-executor/8371:
#0: ffffffff8f347140 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575
#1: ffffffff8f355e78 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock_killable include/linux/rtnetlink.h:145 [inline]
#1: ffffffff8f355e78 (rtnl_mutex){+.+.}-{4:4}, at: register_netdev+0x18/0x60 net/core/dev.c:11533
6 locks held by syz-executor/8386:
1 lock held by syz.2.546/8426:
1 lock held by dhcpcd-run-hook/8435:
=============================================
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 04/18/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
__sys_info lib/sys_info.c:157 [inline]
sys_info+0x135/0x170 lib/sys_info.c:165
check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
watchdog+0xfd3/0x1030 kernel/hung_task.c:561
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 7431 Comm: syz.4.375 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:mark_usage kernel/locking/lockdep.c:4620 [inline]
RIP: 0010:__lock_acquire+0x5ed/0x2cf0 kernel/locking/lockdep.c:5191
Code: 3b 9e f0 0b 00 00 0f 8c 0b ff ff ff 44 89 e0 38 04 24 76 16 e8 54 85 fd 02 85 c0 74 0d 83 3d 9d 9c e8 0d 00 0f 84 0a 08 00 00 <83> 7c 24 10 00 0f 84 a8 00 00 00 41 8b 45 20 66 85 c0 0f 88 8c 00
RSP: 0018:ffffc9000f2b5d30 EFLAGS: 00000093
RAX: 0000000000000004 RBX: ffff888026bc0c40 RCX: 0000000000000001
RDX: 0000000000000004 RSI: 0000000000000005 RDI: 0000000000000000
RBP: ffff888026bc0c20 R08: ffffffff8176d226 R09: ffffffff8dfc8140
R10: ffffc9000f2b6038 R11: ffffffff81af8dc0 R12: 0000000000000004
R13: ffff888026bc0c20 R14: ffff888026bc0000 R15: 0000000000000001
FS: 00007f6ae14a66c0(0000) GS:ffff88812617d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055b281aa2950 CR3: 000000003a8f2000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
slab_free mm/slub.c:6246 [inline]
kmem_cache_free+0x187/0x6c0 mm/slub.c:6373
free_buffer_head+0x55/0x220 fs/buffer.c:2957
try_to_free_buffers+0x25b/0x300 fs/buffer.c:2898
shrink_folio_list+0x24af/0x5220 mm/vmscan.c:1466
shrink_inactive_list mm/vmscan.c:1995 [inline]
shrink_list mm/vmscan.c:2226 [inline]
shrink_lruvec+0x1546/0x28d0 mm/vmscan.c:5969
shrink_node_memcgs mm/vmscan.c:6171 [inline]
shrink_node+0x11f2/0x2950 mm/vmscan.c:6215
shrink_zones mm/vmscan.c:6454 [inline]
do_try_to_free_pages+0x6ed/0x1980 mm/vmscan.c:6516
try_to_free_mem_cgroup_pages+0x30d/0x830 mm/vmscan.c:6838
try_charge_memcg+0x855/0x15a0 mm/memcontrol.c:2618
obj_cgroup_charge_pages mm/memcontrol.c:3060 [inline]
__obj_cgroup_charge mm/memcontrol.c:3358 [inline]
__memcg_slab_post_alloc_hook+0x874/0xed0 mm/memcontrol.c:3486
memcg_slab_post_alloc_hook mm/slub.c:2461 [inline]
slab_post_alloc_hook mm/slub.c:4580 [inline]
slab_alloc_node mm/slub.c:4898 [inline]
kmem_cache_alloc_noprof+0x3f4/0x680 mm/slub.c:4905
alloc_buffer_head+0x2a/0x280 fs/buffer.c:2941
folio_alloc_buffers+0x1fb/0x6f0 fs/buffer.c:838
create_empty_buffers+0x3a/0x530 fs/buffer.c:1588
block_read_full_folio+0x116/0x830 fs/buffer.c:2300
filemap_read_folio+0x137/0x3b0 mm/filemap.c:2502
do_read_cache_folio+0x2bf/0x560 mm/filemap.c:4107
read_mapping_folio include/linux/pagemap.h:1017 [inline]
dir_get_folio fs/minix/dir.c:70 [inline]
minix_find_entry+0x1d1/0x690 fs/minix/dir.c:171
minix_inode_by_name+0x3a/0x280 fs/minix/dir.c:444
minix_lookup+0xc9/0x160 fs/minix/namei.c:30
lookup_open fs/namei.c:4484 [inline]
open_last_lookups fs/namei.c:4611 [inline]
path_openat+0x11cb/0x38a0 fs/namei.c:4855
do_file_open+0x23e/0x4a0 fs/namei.c:4887
do_sys_openat2+0x113/0x200 fs/open.c:1364
do_sys_open fs/open.c:1370 [inline]
__do_sys_openat fs/open.c:1386 [inline]
__se_sys_openat fs/open.c:1381 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1381
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6ae324cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6ae14a6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6ae34c5fa0 RCX: 00007f6ae324cdd9
RDX: 0000000000143041 RSI: 00002000000010c0 RDI: ffffffffffffff9c
RBP: 00007f6ae32e2d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6ae34c6038 R14: 00007f6ae34c5fa0 R15: 00007fff63fbf5a8