syzbot

INFO: task syz-executor.0:6912 blocked for more than 143 seconds.
      Not tainted 6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:24248 pid:6912  tgid:6911  ppid:6472   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0x1796/0x4a00 kernel/sched/core.c:6746
 __schedule_loop kernel/sched/core.c:6823 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6838
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895
 __mutex_lock_common kernel/locking/mutex.c:684 [inline]
 __mutex_lock+0x6a4/0xd70 kernel/locking/mutex.c:752
 exfat_sync_fs+0x6b/0x100 fs/exfat/super.c:53
 iterate_supers+0xc6/0x190 fs/super.c:922
 ksys_sync+0xdb/0x1c0 fs/sync.c:104
 __do_sys_sync+0xe/0x20 fs/sync.c:113
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbc7527dea9
RSP: 002b:00007fbc74dff0c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 00007fbc753abf80 RCX: 00007fbc7527dea9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fbc752ca4a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fbc753abf80 R15: 00007ffcef4666b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:329 [inline]
 #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:781 [inline]
 #0: ffffffff8e334d20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614
4 locks held by klogd/4514:
2 locks held by getty/4832:
 #0: ffff88802ac5a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90002f0e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b5/0x1e10 drivers/tty/n_tty.c:2201
3 locks held by syz-executor.4/6239:
2 locks held by syz-executor.0/6912:
 #0: ffff88802eb360e0 (&type->s_umount_key#82){++++}-{3:3}, at: __super_lock fs/super.c:58 [inline]
 #0: ffff88802eb360e0 (&type->s_umount_key#82){++++}-{3:3}, at: super_lock+0x27c/0x400 fs/super.c:120
 #1: ffff888067a100e0 (&sbi->s_lock){+.+.}-{3:3}, at: exfat_sync_fs+0x6b/0x100 fs/exfat/super.c:53

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 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:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
 watchdog+0xfde/0x1020 kernel/hung_task.c:380
 kthread+0x2f0/0x390 kernel/kthread.c:388
 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6239 Comm: syz-executor.4 Not tainted 6.9.0-rc5-syzkaller-00159-gc942a0cd3603 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__lock_acquire+0xea6/0x1fd0 kernel/locking/lockdep.c:5132
Code: c1 c6 08 31 c6 01 ca 29 f1 89 f3 c1 c3 10 31 cb 01 d6 29 da 89 dd c1 c5 13 31 d5 01 f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 <48> c7 c0 f0 05 a8 8f 48 c1 e8 03 0f b6 04 38 84 c0 0f 85 24 0c 00
RSP: 0018:ffffc90004707270 EFLAGS: 00000006
RAX: 00000000b8441468 RBX: 000000006cc81028 RCX: 000000004047b21a
RDX: 00000000c0e512c6 RSI: 00000000f3c317ad RDI: dffffc0000000000
RBP: 41236fb500000000 R08: ffffffff92f00517 R09: 1ffffffff25e00a2
R10: dffffc0000000000 R11: fffffbfff25e00a3 R12: 0000000067057de0
R13: ffff88802ac15a00 R14: 0000000000000000 R15: ffff88802ac15a00
FS:  000055557b1fe480(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005623348c0600 CR3: 0000000073104000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5754
 fs_reclaim_acquire+0xaf/0x140 mm/page_alloc.c:3715
 might_alloc include/linux/sched/mm.h:312 [inline]
 bdev_getblk+0x42/0x610 fs/buffer.c:1425
 __bread_gfp+0xac/0x430 fs/buffer.c:1474
 sb_bread include/linux/buffer_head.h:321 [inline]
 exfat_get_dentry+0x53b/0x730 fs/exfat/dir.c:689
 exfat_readdir fs/exfat/dir.c:121 [inline]
 exfat_iterate+0xbd7/0x33e0 fs/exfat/dir.c:261
 wrap_directory_iterator+0x94/0xe0 fs/readdir.c:67
 iterate_dir+0x539/0x6f0 fs/readdir.c:110
 __do_sys_getdents64 fs/readdir.c:409 [inline]
 __se_sys_getdents64+0x20d/0x4f0 fs/readdir.c:394
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fdb84aa93a3
Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 52 8b fa ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 b0 ff ff ff f7 d8
RSP: 002b:00007fffb0774388 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 000055557b207970 RCX: 00007fdb84aa93a3
RDX: 0000000000008000 RSI: 000055557b207970 RDI: 0000000000000005
RBP: 000055557b207944 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffb0
R13: 0000000000000010 R14: 000055557b207940 R15: 0000000000000018
 </TASK>