syzbot

INFO: task syz-executor140:5096 blocked for more than 143 seconds.
      Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor140 state:D stack:26832 pid:5096  tgid:5095  ppid:5094   flags:0x00000006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5409 [inline]
 __schedule+0xf15/0x5c70 kernel/sched/core.c:6736
 __schedule_loop kernel/sched/core.c:6813 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6828
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6885
 rwsem_down_write_slowpath kernel/locking/rwsem.c:1178 [inline]
 __down_write_common+0x950/0x13f0 kernel/locking/rwsem.c:1306
 inode_lock_nested include/linux/fs.h:828 [inline]
 filename_create+0x1c2/0x530 fs/namei.c:3892
 do_mkdirat+0xab/0x3a0 fs/namei.c:4141
 __do_sys_mkdir fs/namei.c:4169 [inline]
 __se_sys_mkdir fs/namei.c:4167 [inline]
 __x64_sys_mkdir+0xf1/0x140 fs/namei.c:4167
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f09cb287a99
RSP: 002b:00007f09cb23e218 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f09cb3106c8 RCX: 00007f09cb287a99
RDX: 00007f09cb287a99 RSI: 0000000000000000 RDI: 0000000020000000
RBP: 00007f09cb3106c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f09cb3106cc
R13: 00007f09cb2dc0c0 R14: 0000000020004ac0 R15: 0030656c69662f2e
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
 #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #0: ffffffff8d7b08e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x75/0x340 kernel/locking/lockdep.c:6614
2 locks held by kworker/u8:2/41:
 #0: ffff8880b953e698 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:559
 #1: ffff8880b9528a08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x2d9/0x900 kernel/sched/psi.c:988
2 locks held by getty/4811:
 #0: ffff88802e60a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc900015e02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xfc8/0x1490 drivers/tty/n_tty.c:2201
2 locks held by syz-executor140/5096:
 #0: ffff88802ab6c420 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x10d/0x530 fs/namei.c:3885
 #1: ffff8880771f82b8 (&sb->s_type->i_mutex_key#15/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:828 [inline]
 #1: ffff8880771f82b8 (&sb->s_type->i_mutex_key#15/1){+.+.}-{3:3}, at: filename_create+0x1c2/0x530 fs/namei.c:3892
3 locks held by syz-executor140/5098:

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #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+0x116/0x1f0 lib/dump_stack.c:114
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 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+0xf86/0x1210 kernel/hung_task.c:379
 kthread+0x2c1/0x3a0 kernel/kthread.c:388
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5098 Comm: syz-executor140 Not tainted 6.8.0-syzkaller-08951-gfe46a7dd189e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:lockdep_hardirqs_on_prepare+0x5d/0x420 kernel/locking/lockdep.c:4322
Code: 00 44 8b 0d dd a4 33 0e 45 85 c9 0f 84 4f 01 00 00 65 8b 05 5d d5 98 7e a9 00 00 f0 00 0f 85 3d 01 00 00 65 8b 05 cb 8c 97 7e <85> c0 0f 85 2e 01 00 00 65 8b 05 d0 89 97 7e 85 c0 0f 85 1f 01 00
RSP: 0018:ffffc9000335f688 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1ffffffff1f3d467
RDX: 0000000000000000 RSI: ffffffff8b6e8820 RDI: ffffffff8d233b20
RBP: ffff888077167cb0 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff8f9e6f97 R11: 0000000000000003 R12: 0000000000000000
R13: ffff888077167cb0 R14: 00000000000392c0 R15: fffffffffffffff8
FS:  00007f09cb21d6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055e26dcf8400 CR3: 0000000025d4e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 trace_hardirqs_on+0x36/0x40 kernel/trace/trace_preemptirq.c:61
 lookup_bh_lru fs/buffer.c:1385 [inline]
 __find_get_block+0x4af/0xc70 fs/buffer.c:1397
 bdev_getblk+0x2c/0xc0 fs/buffer.c:1423
 __bread_gfp+0xa9/0x370 fs/buffer.c:1474
 sb_bread include/linux/buffer_head.h:321 [inline]
 __exfat_ent_get fs/exfat/fatent.c:48 [inline]
 exfat_ent_get+0x1ce/0x480 fs/exfat/fatent.c:97
 exfat_readdir+0x11f8/0x1520 fs/exfat/dir.c:187
 exfat_iterate+0x3c2/0xad0 fs/exfat/dir.c:261
 wrap_directory_iterator+0xa5/0xe0 fs/readdir.c:67
 iterate_dir+0x292/0x9e0 fs/readdir.c:110
 __do_sys_getdents64 fs/readdir.c:409 [inline]
 __se_sys_getdents64 fs/readdir.c:394 [inline]
 __x64_sys_getdents64+0x14f/0x2e0 fs/readdir.c:394
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd2/0x260 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x6d/0x75
RIP: 0033:0x7f09cb287a99
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f09cb21d218 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f09cb3106d8 RCX: 00007f09cb287a99
RDX: 0000000000000098 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00007f09cb3106d0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f09cb3106dc
R13: 00007f09cb2dc0c0 R14: 0000000020004ac0 R15: 0030656c69662f2e
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.488 msecs