INFO: task syz.4.2948:17794 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.2948      state:D stack:25552 pid:17794 ppid: 15940 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537
 rwsem_down_read_slowpath+0x548/0x9d0 kernel/locking/rwsem.c:1055
 __down_read_common kernel/locking/rwsem.c:1239 [inline]
 __down_read kernel/locking/rwsem.c:1252 [inline]
 down_read+0x96/0x2e0 kernel/locking/rwsem.c:1500
 iterate_supers+0xa4/0x1d0 fs/super.c:716
 ksys_sync+0x9d/0x170 fs/sync.c:102
 __ia32_sys_sync+0xa/0x10 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb8a257d799
RSP: 002b:00007fb8a07b6028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fb8a27f7090 RCX: 00007fb8a257d799
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb8a27f7090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb8a27f7128 R14: 00007fb8a27f7090 R15: 00007ffd6d68cdb8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by udevd/3562:
 #0: ffff888020c60518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915
 #1: ffff88814718a468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071
2 locks held by getty/3947:
 #0: ffff88802cadd098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158
1 lock held by udevd/4442:
 #0: ffff888020c60518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
1 lock held by syz.5.2545/15690:
 #0: ffff888077d520e0 (&type->s_umount_key#122/1){+.+.}-{3:3}, at: alloc_super+0x201/0x950 fs/super.c:229
1 lock held by syz.4.2948/17794:
 #0: ffff888077d520e0 (&type->s_umount_key#128){++++}-{3:3}, at: iterate_supers+0xa4/0x1d0 fs/super.c:716
1 lock held by syz.7.3346/20529:
2 locks held by syz.6.3370/20626:
 #0: ffffffff8c808968 (uuid_mutex){+.+.}-{3:3}, at: btrfs_mount_root+0x271/0x930 fs/btrfs/super.c:1708
 #1: ffff888020c60518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820
2 locks held by sed/20657:

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6551 Comm: kworker/1:16 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:chacha_block_generic+0x116/0xd20 lib/crypto/chacha.c:86
Code: 84 c0 0f 85 4a 05 00 00 45 89 2f 44 8b 6c 24 18 4d 8d 7e 08 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 51 05 00 00 45 03 2f <4c> 8d 7b 08 4c 8d 63 0b 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 0f
RSP: 0018:ffffc90003eef800 EFLAGS: 00000007
RAX: 0000000000000000 RBX: ffffc90003eef900 RCX: 00000000c51e9e6d
RDX: dffffc0000000000 RSI: ffffc90003eef834 RDI: ffffc90003eef83c
RBP: ffffc90003eef890 R08: 00000000d1c4cb78 R09: ffffc90003eef838
R10: 000000003886dc03 R11: 00000000f7a3b862 R12: ffffc90003eef907
R13: 000000003e80cb9f R14: ffffc90003eefa20 R15: ffffc90003eefa28
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055ca3c825950 CR3: 000000002b14e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 chacha20_block include/crypto/chacha.h:36 [inline]
 crng_fast_key_erasure drivers/char/random.c:296 [inline]
 crng_make_state+0x2f9/0x670 drivers/char/random.c:391
 _get_random_bytes+0xfc/0x250 drivers/char/random.c:405
 eth_random_addr include/linux/etherdevice.h:225 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:671 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline]
 nsim_dev_trap_report_work+0x346/0xb40 drivers/net/netdevsim/dev.c:762
 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310
 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>