INFO: task syz.5.407:6467 blocked for more than 144 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.407 state:D stack:28744 pid:6467 ppid:4550 flags:0x00004004
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
rwsem_down_read_slowpath+0x4f4/0x840 kernel/locking/rwsem.c:1094
__down_read_common kernel/locking/rwsem.c:1261 [inline]
__down_read kernel/locking/rwsem.c:1274 [inline]
down_read+0x94/0x2d0 kernel/locking/rwsem.c:1522
iterate_supers+0xa4/0x1d0 fs/super.c:755
ksys_sync+0x91/0x150 fs/sync.c:102
__ia32_sys_sync+0xa/0x10 fs/sync.c:113
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f2d9b78f6c9
RSP: 002b:00007f2d9c5f7038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007f2d9b9e6090 RCX: 00007f2d9b78f6c9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f2d9b9e6090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2d9b9e6128 R14: 00007f2d9b9e6090 R15: 00007ffee7dee7e8
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8cb2be50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8cb2aca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
2 locks held by getty/4026:
#0: ffff88814d702098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
4 locks held by syz.0.199/5390:
1 lock held by syz.5.407/6467:
#0: ffff88801b6c20e0 (&type->s_umount_key#31){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:755
2 locks held by syz.7.635/7657:
1 lock held by syz.1.675/7847:
2 locks held by rm/7855:
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7847 Comm: syz.1.675 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3718 [inline]
RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3738 [inline]
RIP: 0010:validate_chain kernel/locking/lockdep.c:3793 [inline]
RIP: 0010:__lock_acquire+0x1449/0x7c50 kernel/locking/lockdep.c:5049
Code: 00 00 00 42 80 3c 00 00 74 12 4c 89 e7 e8 bf f3 6d 00 49 b8 00 00 00 00 00 fc ff df 49 8b 1c 24 48 85 db 0f 94 c0 48 83 c3 f8 <0f> 94 c1 08 c1 4c 89 b4 24 90 00 00 00 0f 84 99 02 00 00 e8 0f a7
RSP: 0018:ffffc9000e99f220 EFLAGS: 00000097
RAX: 1ffffffff20f0500 RBX: ffffffff90b356a0 RCX: ffffffff81631130
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90ae22e0
RBP: ffffc9000e99f470 R08: dffffc0000000000 R09: fffffbfff215c45d
R10: fffffbfff215c45d R11: 1ffffffff215c45c R12: ffffffff90782aa8
R13: 00000000cac8fbf7 R14: df8262430aad80f0 R15: ffff888074952890
FS: 00007eff8cb5f6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000001bf00000000 CR3: 0000000028b85000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
__skb_try_recv_datagram+0x147/0x4d0 net/core/datagram.c:262
__unix_dgram_recvmsg+0x2d1/0xd70 net/unix/af_unix.c:2451
____sys_recvmsg+0x292/0x580 net/socket.c:-1
___sys_recvmsg+0x1b2/0x510 net/socket.c:2780
do_recvmmsg+0x359/0x7d0 net/socket.c:2874
__sys_recvmmsg net/socket.c:2953 [inline]
__do_sys_recvmmsg net/socket.c:2976 [inline]
__se_sys_recvmmsg net/socket.c:2969 [inline]
__x64_sys_recvmmsg+0x18d/0x240 net/socket.c:2969
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7eff8bd8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007eff8cb5f038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007eff8bfe6090 RCX: 00007eff8bd8f6c9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007eff8be11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007eff8bfe6128 R14: 00007eff8bfe6090 R15: 00007ffe41ef0ad8