syzbot

INFO: task syz-executor:5906 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21800 pid:5906  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 io_schedule+0x80/0xd0 kernel/sched/core.c:9023
 folio_wait_bit_common+0x881/0xfa0 mm/filemap.c:1329
 __filemap_get_folio+0xbc/0xbe0 mm/filemap.c:1910
 truncate_inode_pages_range+0x425/0xea0 mm/truncate.c:401
 evict+0x4ca/0x8a0 fs/inode.c:707
 dispose_list fs/inode.c:738 [inline]
 evict_inodes+0x64a/0x6e0 fs/inode.c:792
 generic_shutdown_super+0x97/0x2b0 fs/super.c:672
 kill_block_super+0x44/0x90 fs/super.c:1660
 deactivate_locked_super+0x97/0x100 fs/super.c:481
 cleanup_mnt+0x3d7/0x460 fs/namespace.c:1259
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5d0339e097
RSP: 002b:00007fff59999e18 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f5d034322ca RCX: 00007f5d0339e097
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fff59999ed0
RBP: 00007fff59999ed0 R08: 00007fff5999aed0 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fff5999af60
R13: 00007f5d034322ca R14: 00000000000260c1 R15: 00007fff5999afa0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
2 locks held by kworker/u4:4/59:
 #0: ffff8880b8e3c298 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
 #1: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #1: ffff8880b8e28a00 (psi_seq){-.-.}-{0:0}, at: __schedule+0x21d3/0x4660 kernel/sched/core.c:6695
2 locks held by getty/5528:
 #0: ffff88803171a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5906:
 #0: ffff8880781760e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff8880781760e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff8880781760e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
1 lock held by syz-executor/5954:
 #0: ffff88807e3300e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88807e3300e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88807e3300e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
1 lock held by syz-executor/5976:
 #0: ffff888020e940e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888020e940e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888020e940e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
1 lock held by syz-executor/5991:
 #0: ffff888060a9e0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888060a9e0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888060a9e0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
1 lock held by syz-executor/6006:
 #0: ffff8880193960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff8880193960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff8880193960e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
1 lock held by syz-executor/6034:
 #0: ffff888059ab80e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888059ab80e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888059ab80e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
1 lock held by syz-executor/6055:
 #0: ffff888058fbe0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff888058fbe0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff888058fbe0e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513
1 lock held by syz-executor/6078:
 #0: ffff88805a1580e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff88805a1580e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff88805a1580e0 (&type->s_umount_key#56){+.+.}-{3:3}, at: deactivate_super+0xa4/0xe0 fs/super.c:513

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf59/0xfa0 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3491 Comm: kworker/u4:11 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:memset_orig+0x3e/0xac arch/x86/lib/memset_64.S:70
Code: 01 48 0f af c1 41 89 f9 41 83 e1 07 75 6c 48 89 d1 48 c1 e9 06 74 35 0f 1f 44 00 00 48 ff c9 48 89 07 48 89 47 08 48 89 47 10 <48> 89 47 18 48 89 47 20 48 89 47 28 48 89 47 30 48 89 47 38 48 8d
RSP: 0018:ffffc9000cf377b8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880b8e39090 RCX: 0000000000000000
RDX: 0000000000000040 RSI: 0000000000000000 RDI: ffffc9000cf37800
RBP: ffffc9000cf378b0 R08: ffffc9000cf3783f R09: 0000000000000000
R10: ffffc9000cf37800 R11: fffff520019e6f08 R12: ffffc9000cf379e0
R13: ffffc9000cf37800 R14: dffffc0000000000 R15: 1ffff920019e6efc
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055742c086168 CR3: 000000007d19f000 CR4: 00000000003506f0
Call Trace:
 <TASK>
 crng_fast_key_erasure+0x13e/0x260 drivers/char/random.c:291
 crng_make_state+0x259/0x700 drivers/char/random.c:364
 _get_random_bytes+0x100/0x250 drivers/char/random.c:378
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:776 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x60c/0xa90 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2653 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
 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>