INFO: task syz.1.125:6522 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.125 state:D stack:25160 pid:6522 tgid:6521 ppid:5599 task_flags:0x400140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x16ec/0x5620 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
percpu_rwsem_wait+0x317/0x480 kernel/locking/percpu-rwsem.c:164
__percpu_down_read+0xfc/0x140 kernel/locking/percpu-rwsem.c:180
percpu_down_read_internal include/linux/percpu-rwsem.h:67 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x18e/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:493
open_last_lookups fs/namei.c:4600 [inline]
path_openat+0xaec/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: 0033:0x7f803ac1ce59
RSP: 002b:00007f8038e76028 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f803ae95fa0 RCX: 00007f803ac1ce59
RDX: 0000000000143042 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f803acb2d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000138 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f803ae96038 R14: 00007f803ae95fa0 R15: 00007fff4cab04a8
Showing all locks held in the system:
2 locks held by kworker/u8:0/12:
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90000117c40 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90000117c40 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
1 lock held by khungtaskd/38:
#0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
#0: ffffffff8dfc8080 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
#0: ffffffff8dfc8080 (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:
#0: ffff88803221d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88803221d138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90000b57c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90000b57c40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
#2: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4746
2 locks held by kworker/u8:4/66:
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc9000151fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000151fc40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
3 locks held by kworker/u8:7/166:
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc9000397fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc9000397fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
3 locks held by kworker/u8:10/1351:
#0: ffff888064dbf138 ((wq_completion)loop2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff888064dbf138 ((wq_completion)loop2){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90006707c40 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90006707c40 ((work_completion)(&worker->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffff888026392160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:96 [inline]
#2: ffff888026392160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0x125/0x11b0 drivers/block/loop.c:1953
4 locks held by kworker/u8:12/1419:
#0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline]
#0: ffff88801b290938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397
#1: ffffc90006a07c40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline]
#1: ffffc90006a07c40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397
#2: ffffffff8f3497a0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
#3: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: default_device_exit_batch+0xe5/0x9e0 net/core/dev.c:13062
2 locks held by dhcpcd/5260:
#0: ffff888036130928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404
#1: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6864
2 locks held by getty/5354:
#0: ffff888036c550a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5600:
#0: ffff888063d86480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
2 locks held by udevd/5706:
1 lock held by udevd/5802:
#0: ffff8880115d6480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
1 lock held by udevd/5804:
#0: ffff8880115d6480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
1 lock held by syz.1.125/6522:
#0: ffff88803596e480 (sb_writers#14){++++}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
1 lock held by syz-executor/8032:
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8f3584f8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4109
2 locks held by syz.3.399/8267:
6 locks held by syz.2.401/8270:
=============================================
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: 8270 Comm: syz.2.401 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__bfs kernel/locking/lockdep.c:1815 [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 kernel/locking/lockdep.c:3908 [inline]
RIP: 0010:__lock_acquire+0x197b/0x2cf0 kernel/locking/lockdep.c:5237
Code: 13 25 ff 0f 00 00 39 05 bf 55 d2 11 73 06 89 05 b7 55 d2 11 48 8b 02 48 89 df 4c 39 e8 0f 84 2c fe ff ff 4c 89 60 30 48 8b 00 <4c> 39 e8 75 f4 48 89 df e9 18 fe ff ff 48 89 fb 48 c7 c7 70 53 e9
RSP: 0018:ffffc9001f7f66c8 EFLAGS: 00000002
RAX: ffffffff960fe908 RBX: 00000000000003cc RCX: 000000000000004d
RDX: ffffffff95f7ab88 RSI: ffff88802d6ee900 RDI: 00000000000003cc
RBP: e551e745617b6525 R08: ffffc9001f7f6690 R09: 0000000000000020
R10: dffffc0000000000 R11: ffffffff81a0b320 R12: ffffffff95f7abf8
R13: ffffffff9314eca8 R14: ffff88802d6edc40 R15: 000000000000004c
FS: 00007f8c29fa66c0(0000) GS:ffff888126171000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556427ba68 CR3: 000000003ff22000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
mark_wakeup_next_waiter kernel/locking/rtmutex.c:1327 [inline]
rt_mutex_slowunlock+0x18e/0x8b0 kernel/locking/rtmutex.c:1475
spin_unlock_irq include/linux/spinlock_rt.h:122 [inline]
loop_queue_work drivers/block/loop.c:863 [inline]
loop_queue_rq+0x9f8/0xb00 drivers/block/loop.c:1889
__blk_mq_issue_directly block/blk-mq.c:2725 [inline]
blk_mq_request_issue_directly+0x3be/0x6d0 block/blk-mq.c:2812
blk_mq_issue_direct+0x2a0/0x660 block/blk-mq.c:2833
blk_mq_dispatch_queue_requests+0x6fe/0x800 block/blk-mq.c:2908
blk_mq_flush_plug_list+0x456/0x570 block/blk-mq.c:2991
__blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1230
blk_finish_plug block/blk-core.c:1257 [inline]
__submit_bio+0x28d/0x580 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:753
__ext4_read_bh fs/ext4/super.c:181 [inline]
ext4_read_bh+0x1af/0x260 fs/ext4/super.c:206
ext4_bread+0x12d/0x180 fs/ext4/inode.c:1061
ext4_quota_write+0x239/0x580 fs/ext4/super.c:7398
write_blk fs/quota/quota_tree.c:70 [inline]
get_free_dqblk+0x368/0x720 fs/quota/quota_tree.c:136
do_insert_tree+0x256/0x11d0 fs/quota/quota_tree.c:347
do_insert_tree+0x9d7/0x11d0 fs/quota/quota_tree.c:402
do_insert_tree+0x9b2/0x11d0 fs/quota/quota_tree.c:402
dq_insert_tree fs/quota/quota_tree.c:432 [inline]
qtree_write_dquot+0x4b1/0x5e0 fs/quota/quota_tree.c:451
v2_write_dquot+0x183/0x260 fs/quota/quota_v2.c:372
dquot_acquire+0x328/0x620 fs/quota/dquot.c:498
ext4_acquire_dquot+0x2e9/0x4c0 fs/ext4/super.c:7030
dqget+0x744/0xc60 fs/quota/dquot.c:1002
__dquot_initialize+0x3ba/0xd30 fs/quota/dquot.c:1530
ext4_process_orphan+0x54/0x300 fs/ext4/orphan.c:327
ext4_orphan_cleanup+0xc38/0x1470 fs/ext4/orphan.c:472
__ext4_fill_super fs/ext4/super.c:5701 [inline]
ext4_fill_super+0x59bb/0x62d0 fs/ext4/super.c:5824
get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
vfs_get_tree+0x92/0x2a0 fs/super.c:1754
fc_mount fs/namespace.c:1193 [inline]
do_new_mount_fc fs/namespace.c:3758 [inline]
do_new_mount+0x341/0xd30 fs/namespace.c:3834
do_mount fs/namespace.c:4167 [inline]
__do_sys_mount fs/namespace.c:4383 [inline]
__se_sys_mount+0x31d/0x420 fs/namespace.c:4360
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: 0033:0x7f8c2bd4e0ca
Code: 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8c29fa5e58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f8c29fa5ee0 RCX: 00007f8c2bd4e0ca
RDX: 0000200000000140 RSI: 0000200000000040 RDI: 00007f8c29fa5ea0
RBP: 0000200000000140 R08: 00007f8c29fa5ee0 R09: 0000000001018e58
R10: 0000000001018e58 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f8c29fa5ea0 R14: 000000000000061f R15: 0000200000000000