syzbot

INFO: task syz.1.2:5917 blocked for more than 143 seconds.
      Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.2         state:D stack:24088 pid:5917  tgid:5911  ppid:5825   flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5328 [inline]
 __schedule+0x17fa/0x4bd0 kernel/sched/core.c:6693
 __schedule_loop kernel/sched/core.c:6770 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6785
 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
 kthread_stop+0x19e/0x640 kernel/kthread.c:712
 f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:239
 f2fs_do_shutdown+0x292/0x610 fs/f2fs/file.c:2350
 f2fs_ioc_shutdown fs/f2fs/file.c:2395 [inline]
 __f2fs_ioctl+0x4297/0xb8f0 fs/f2fs/file.c:4424
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc375d7e719
RSP: 002b:00007fc376bac038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc375f36058 RCX: 00007fc375d7e719
RDX: 0000000020000080 RSI: 000000008004587d RDI: 0000000000000005
RBP: 00007fc375df175e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc375f36058 R15: 00007fffa5e25108
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/30:
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720
2 locks held by getty/5582:
 #0: ffff888031f7e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211
2 locks held by syz.1.2/5917:
 #0: ffff888012452420 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write_file+0x5e/0x200 fs/namespace.c:559
 #1: ffff8880124520e0 (&type->s_umount_key#50){++++}-{3:3}, at: f2fs_do_shutdown+0x28a/0x610 fs/f2fs/file.c:2348
1 lock held by syz-executor/6137:
 #0: ffff8880342240e0 (&type->s_umount_key#71){+.+.}-{3:3}, at: __super_lock fs/super.c:56 [inline]
 #0: ffff8880342240e0 (&type->s_umount_key#71){+.+.}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline]
 #0: ffff8880342240e0 (&type->s_umount_key#71){+.+.}-{3:3}, at: deactivate_super+0xb5/0xf0 fs/super.c:505
2 locks held by dhcpcd/7913:
 #0: ffff88807b143808 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #0: ffff88807b143808 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: __sock_release net/socket.c:657 [inline]
 #0: ffff88807b143808 (&sb->s_type->i_mutex_key#9){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1426
 #1: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #1: ffffffff8e93d338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976
2 locks held by syz.1.306/8682:
2 locks held by syz.6.307/8687:
2 locks held by syz.2.309/8696:
4 locks held by sed/8709:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xff4/0x1040 kernel/hung_task.c:379
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 6137 Comm: syz-executor Not tainted 6.12.0-rc7-syzkaller-00125-gcfaaa7d010d1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
RIP: 0010:unwind_get_return_address+0x8/0x90 arch/x86/kernel/unwind_orc.c:365
Code: fe ff ff e8 3a e2 7d 0a 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 <53> 48 89 fb 49 be 00 00 00 00 00 fc ff df 48 89 f8 48 c1 e8 03 42
RSP: 0018:ffffc90004ccf248 EFLAGS: 00000202
RAX: 0000000080000001 RBX: ffffc90004ccf260 RCX: 0000000080000000
RDX: ffffffff91467eea RSI: 0000000000000000 RDI: ffffc90004ccf260
RBP: ffffc90004ccf2f0 R08: 0000000000000021 R09: ffffc90004ccf350
R10: ffffc90004ccf2b0 R11: ffffffff8180a210 R12: ffff888034305a00
R13: ffffffff8180a210 R14: ffffc90004ccf340 R15: 0000000000000000
FS:  000055558c23d500(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000557c8dd2d950 CR3: 0000000065178000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 arch_stack_walk+0xfd/0x150 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:2342 [inline]
 slab_free mm/slub.c:4579 [inline]
 kmem_cache_free+0x1a2/0x420 mm/slub.c:4681
 free_buffer_head+0x54/0x240 fs/buffer.c:3036
 try_to_free_buffers+0x311/0x5f0 fs/buffer.c:2977
 block_invalidate_folio+0x4b3/0x5f0 fs/buffer.c:1650
 folio_invalidate mm/truncate.c:141 [inline]
 truncate_cleanup_folio+0x11a/0x450 mm/truncate.c:161
 truncate_inode_pages_range+0x2da/0xfc0 mm/truncate.c:342
 kill_bdev block/bdev.c:91 [inline]
 blkdev_flush_mapping+0x108/0x270 block/bdev.c:671
 blkdev_put_whole block/bdev.c:678 [inline]
 bdev_release+0x460/0x700 block/bdev.c:1103
 blkdev_release+0x15/0x20 block/fops.c:639
 __fput+0x23f/0x880 fs/file_table.c:431
 task_work_run+0x24f/0x310 kernel/task_work.c:239
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:114 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2c0f17fa47
Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffff279db68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f2c0f17fa47
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffff279dc20
RBP: 00007ffff279dc20 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffff279eca0
R13: 00007f2c0f1f15fc R14: 0000000000037d34 R15: 00007ffff279ece0
 </TASK>