INFO: task syz.9.3274:18780 blocked for more than 144 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.9.3274      state:D stack:26536 pid:18780 ppid:13433  flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 rwsem_down_read_slowpath+0x4f8/0x840 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1250 [inline]
 __down_read kernel/locking/rwsem.c:1263 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1522
 __super_lock fs/super.c:58 [inline]
 super_lock+0x167/0x360 fs/super.c:117
 super_lock_shared fs/super.c:146 [inline]
 iterate_supers+0x80/0x170 fs/super.c:977
 ksys_sync+0x95/0x150 fs/sync.c:102
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd249d8efc9
RSP: 002b:00007fd247fd5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fd249fe6180 RCX: 00007fd249d8efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fd249fe6180 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd249fe6218 R14: 00007fd249fe6180 R15: 00007ffe964b1188
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by getty/5549:
 #0: ffff888030eaa0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/9535:
 #0: ffff88807d3820e0 (&type->s_umount_key#90){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88807d3820e0 (&type->s_umount_key#90){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88807d3820e0 (&type->s_umount_key#90){++++}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
2 locks held by kworker/1:0/13329:
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc900053e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc900053e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
3 locks held by kworker/u4:20/16623:
1 lock held by syz.9.3274/18780:
 #0: ffff88807d3820e0 (&type->s_umount_key#90){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88807d3820e0 (&type->s_umount_key#90){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
1 lock held by syz.7.3322/18998:
 #0: ffff88807d3820e0 (&type->s_umount_key#90){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88807d3820e0 (&type->s_umount_key#90){++++}-{3:3}, at: super_lock+0x167/0x360 fs/super.c:117
1 lock held by syz.2.3468/19948:
 #0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline]
 #0: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz.3.3469/19967:
4 locks held by dhcpcd-run-hook/19943:

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf41/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 19967 Comm: syz.3.3469 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d cc fc c4 0c 48 89 de 5b e9 53 88 56 00 cc cc cc <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0d e0 2c 7e 7e 65 8b 15 e1 2c 7e
RSP: 0018:ffffc9000465f628 EFLAGS: 00000246
RAX: 1ffff110056ba799 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000f5e4000 RSI: 0000000000066b18 RDI: 0000000000066b19
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8866d530
R10: dffffc0000000000 R11: fffffbfff1c950ae R12: ffff88802b5d3cc8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS:  00007f00e01df6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055555ef8c5c8 CR3: 00000000335db000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 __skb_datagram_iter+0x613/0x780 net/core/datagram.c:463
 skb_copy_datagram_iter+0xb1/0x200 net/core/datagram.c:535
 skb_copy_datagram_msg include/linux/skbuff.h:4020 [inline]
 __unix_dgram_recvmsg+0x65c/0xd60 net/unix/af_unix.c:2449
 sock_recvmsg_nosec+0x82/0xd0 net/socket.c:1046
 ____sys_recvmsg+0x49b/0x5b0 net/socket.c:2812
 ___sys_recvmsg+0x1b6/0x510 net/socket.c:2856
 do_recvmmsg+0x360/0x7d0 net/socket.c:2950
 __sys_recvmmsg net/socket.c:3029 [inline]
 __do_sys_recvmmsg net/socket.c:3052 [inline]
 __se_sys_recvmmsg net/socket.c:3045 [inline]
 __x64_sys_recvmmsg+0x191/0x240 net/socket.c:3045
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f00df38efc9
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:00007f00e01df038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f00df5e6360 RCX: 00007f00df38efc9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f00df411f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f00df5e63f8 R14: 00007f00df5e6360 R15: 00007fffde192428
 </TASK>