INFO: task syz.4.55:6268 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.55 state:D stack:28136 pid:6268 tgid:6262 ppid:5809 task_flags:0x400040 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7241
rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked+0x1dfe/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:1027 [inline]
open_last_lookups fs/namei.c:4546 [inline]
path_openat+0xb53/0x3df0 fs/namei.c:4793
do_filp_open+0x1fa/0x410 fs/namei.c:4823
do_sys_openat2+0x121/0x200 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb17b84f749
RSP: 002b:00007fb179a95038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb17baa6090 RCX: 00007fb17b84f749
RDX: 000000000000275a RSI: 00002000000004c0 RDI: ffffffffffffff9c
RBP: 00007fb17b8d3f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb17baa6128 R14: 00007fb17baa6090 R15: 00007ffcd0a5b308
Showing all locks held in the system:
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:8/1122:
#0: ffff88814047c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff88814047c938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90004927bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90004927bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff88803bc100d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
#3: ffff88805cd50ba8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
3 locks held by kworker/u8:19/3577:
#0: ffff888027121938 ((wq_completion)loop8){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888027121938 ((wq_completion)loop8){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc9000d187bc0 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc9000d187bc0 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffff888023f4c160 (&lo->lo_work_lock){+.+.}-{3:3}, at: spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
#2: ffff888023f4c160 (&lo->lo_work_lock){+.+.}-{3:3}, at: loop_process_work+0xf8/0x11a0 drivers/block/loop.c:1975
7 locks held by kworker/u8:20/3687:
1 lock held by dhcpcd/5469:
#0: ffffffff8e8a5938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8e8a5938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8e8a5938 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8ec/0x1c90 net/core/rtnetlink.c:4071
2 locks held by getty/5564:
#0: ffff88803477a0a0 (&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+0x44f/0x1460 drivers/tty/n_tty.c:2211
2 locks held by udevd/5934:
2 locks held by udevd/5935:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: sock_def_readable+0xae/0x540 net/core/sock.c:3608
#1: ffff88814a473b18 (&ei->socket.wq.wait){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline]
#1: ffff88814a473b18 (&ei->socket.wq.wait){+.+.}-{3:3}, at: __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124
4 locks held by syz.4.55/6263:
2 locks held by syz.4.55/6268:
#0: ffff88803bc10480 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:499
#1: ffff88805cd50f78 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
#1: ffff88805cd50f78 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: open_last_lookups fs/namei.c:4546 [inline]
#1: ffff88805cd50f78 (&type->i_mutex_dir_key#14){++++}-{4:4}, at: path_openat+0xb53/0x3df0 fs/namei.c:4793
4 locks held by kworker/u8:25/7004:
2 locks held by syz.3.203/7428:
#0: ffff88803bc100d0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
#0: ffff88803bc100d0 (&type->s_umount_key#65){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
#1: ffff888023dae8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:397 [inline]
#1: ffff888023dae8c0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x1af/0xb80 fs/fs-writeback.c:2892
4 locks held by syz-executor/7902:
1 lock held by syz.8.291/8048:
#0: ffff8880330060d0 (&type->s_umount_key#57/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
5 locks held by syz.7.297/8083:
1 lock held by syz.1.296/8085:
=============================================
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+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:160 [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:346 [inline]
watchdog+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 8083 Comm: syz.7.297 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:consume_stock mm/memcontrol.c:1845 [inline]
RIP: 0010:try_charge_memcg+0x53e/0x1360 mm/memcontrol.c:2345
Code: 00 00 eb 05 b8 06 00 00 00 4d 8d 2c 04 49 81 c5 80 00 00 00 4d 89 ee 49 c1 ee 03 48 b8 00 00 00 00 00 fc ff df 41 0f b6 04 06 <84> c0 0f 85 5d 02 00 00 41 0f b6 5d 00 41 39 df 4c 8b 64 24 18 76
RSP: 0000:ffffc9000c0ffa00 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: ffff88801b2bd100 RCX: 0000000000000246
RDX: 00000000b2cf9a2d RSI: ffffffff8b3f5a40 RDI: ffffffff8b3f5a00
RBP: ffffc9000c0ffb50 R08: ffffffff8ad4262d R09: ffffffff8d5ae940
R10: dffffc0000000000 R11: fffffbfff1db66cf R12: ffff8880b883cb00
R13: ffff8880b883cb81 R14: 1ffff11017107970 R15: 0000000000000001
FS: 00007fc78ce7e6c0(0000) GS:ffff888126cee000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc784c2d000 CR3: 000000003ec9a000 CR4: 00000000003526f0
Call Trace:
try_charge mm/memcontrol.c:2530 [inline]
charge_memcg+0x9f/0x180 mm/memcontrol.c:4728
__mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:4745
mem_cgroup_charge include/linux/memcontrol.h:663 [inline]
folio_prealloc+0x51/0x180 mm/memory.c:1198
alloc_anon_folio mm/memory.c:5165 [inline]
do_anonymous_page mm/memory.c:5222 [inline]
do_pte_missing+0x86a/0x27a0 mm/memory.c:4399
handle_pte_fault mm/memory.c:6273 [inline]
__handle_mm_fault mm/memory.c:6411 [inline]
handle_mm_fault+0xcc1/0x1330 mm/memory.c:6580
do_user_addr_fault+0xa7c/0x1380 arch/x86/mm/fault.c:1336
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7fc78eae09f0
Code: 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 47 0f b6 0c 08 45 84 c9 74 08 <45> 88 0c 00 49 8b 47 10 48 83 c0 01 49 89 47 10 83 e9 01 73 d3 41
RSP: 002b:00007fc78ce7d4a0 EFLAGS: 00010282
RAX: 00000000001cf000 RBX: 00007fc78ce7d540 RCX: 0000000000000016
RDX: 00000000000005ff RSI: 0000000000000200 RDI: 00007fc78ce7d5e0
RBP: 00000000000000e8 R08: 00007fc784a5e000 R09: 00000000000000fe
R10: 0000200000012f42 R11: 00000000000097a4 R12: 0000000000000181
R13: 00007fc78ecbfc40 R14: 0000000000000011 R15: 00007fc78ce7d5e0