syzbot


INFO: task hung in do_rmdir (4)

Status: auto-closed as invalid on 2022/05/08 10:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 239d, last: 239d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in do_rmdir (3) 10 580d 656d 0/24 auto-closed as invalid on 2021/06/01 08:24
linux-4.19 INFO: task hung in do_rmdir 1 84d 84d 0/1 upstream: reported on 2022/07/13 04:55
android-49 INFO: task hung in do_rmdir 1 1606d 1606d 0/3 auto-closed as invalid on 2019/02/22 12:59
upstream INFO: task hung in do_rmdir (2) 3 1364d 1498d 0/24 closed as dup on 2018/09/11 15:01
upstream INFO: task hung in do_rmdir 1 1652d 1652d 0/24 closed as invalid on 2018/03/27 11:14

Sample crash report:
INFO: task syz-executor.0:4026 blocked for more than 143 seconds.
      Not tainted 5.17.0-rc2-syzkaller-00398-gd8ad2ce873ab #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:28912 pid: 4026 ppid:  3901 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4986 [inline]
 __schedule+0x926/0x1080 kernel/sched/core.c:6295
 schedule+0x12b/0x1f0 kernel/sched/core.c:6368
 rwsem_down_write_slowpath+0xdb7/0x1480 kernel/locking/rwsem.c:1142
 __down_write_common kernel/locking/rwsem.c:1259 [inline]
 __down_write kernel/locking/rwsem.c:1268 [inline]
 down_write_nested+0x16f/0x180 kernel/locking/rwsem.c:1625
 inode_lock_nested include/linux/fs.h:812 [inline]
 do_rmdir+0x250/0x6e0 fs/namei.c:4067
 __do_sys_unlinkat fs/namei.c:4260 [inline]
 __se_sys_unlinkat fs/namei.c:4254 [inline]
 __x64_sys_unlinkat+0xdc/0xf0 fs/namei.c:4254
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f667d762059
RSP: 002b:00007f667c095168 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007f667d875100 RCX: 00007f667d762059
RDX: 0000000000000200 RSI: 0000000020000080 RDI: 0000000000000005
RBP: 00007f667d7bc08d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcd2c4e7af R14: 00007f667c095300 R15: 0000000000022000
 </TASK>
INFO: task syz-executor.0:4027 blocked for more than 143 seconds.
      Not tainted 5.17.0-rc2-syzkaller-00398-gd8ad2ce873ab #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:28720 pid: 4027 ppid:  3901 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4986 [inline]
 __schedule+0x926/0x1080 kernel/sched/core.c:6295
 schedule+0x12b/0x1f0 kernel/sched/core.c:6368
 rwsem_down_write_slowpath+0xdb7/0x1480 kernel/locking/rwsem.c:1142
 __down_write_common kernel/locking/rwsem.c:1259 [inline]
 __down_write kernel/locking/rwsem.c:1268 [inline]
 down_write_nested+0x16f/0x180 kernel/locking/rwsem.c:1625
 inode_lock_nested include/linux/fs.h:812 [inline]
 filename_create+0x1da/0x4e0 fs/namei.c:3704
 do_mknodat+0x13d/0x760 fs/namei.c:3848
 __do_sys_mknodat fs/namei.c:3890 [inline]
 __se_sys_mknodat fs/namei.c:3887 [inline]
 __x64_sys_mknodat+0xa5/0xc0 fs/namei.c:3887
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f667d762059
RSP: 002b:00007f667c074168 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007f667d8751d0 RCX: 00007f667d762059
RDX: 0000000000000000 RSI: 0000000020001240 RDI: 0000000000000005
RBP: 00007f667d7bc08d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcd2c4e7af R14: 00007f667c074300 R15: 0000000000022000
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1db60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3278:
 #0: ffff88807f3b1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
 #1: ffffc90002b662e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6c5/0x1c60 drivers/tty/n_tty.c:2077
3 locks held by kworker/u4:4/411:
2 locks held by syz-executor.0/4026:
 #0: ffff88807ca06460 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
 #1: ffff888028fcb6b0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:812 [inline]
 #1: ffff888028fcb6b0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: do_rmdir+0x250/0x6e0 fs/namei.c:4067
2 locks held by syz-executor.0/4027:
 #0: ffff88807ca06460 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
 #1: ffff888028fcb6b0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:812 [inline]
 #1: ffff888028fcb6b0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: filename_create+0x1da/0x4e0 fs/namei.c:3704
1 lock held by syz-executor.0/4029:

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.17.0-rc2-syzkaller-00398-gd8ad2ce873ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xc82/0xcd0 kernel/hung_task.c:369
 kthread+0x2a3/0x2d0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4029 Comm: syz-executor.0 Not tainted 5.17.0-rc2-syzkaller-00398-gd8ad2ce873ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:196
Code: 84 00 00 00 00 00 0f 1f 40 00 be 0d 00 00 00 48 c7 c7 e0 b1 b5 8c e8 6f 97 4b 00 c3 cc cc cc cc cc cc cc cc cc cc cc cc cc cc <48> 8b 04 24 65 48 8b 0c 25 80 6f 02 00 65 8b 15 e4 c1 7c 7e f7 c2
RSP: 0018:ffffc90002c5f4f8 EFLAGS: 00000246
RAX: 1ffffd4000407eec RBX: ffffea000203f760 RCX: ffffffff81aff8e6
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea000203f774
RBP: ffffc90002c5f670 R08: dffffc0000000000 R09: fffff94000407eef
R10: fffff94000407eef R11: 0000000000000000 R12: 0000000000000000
R13: dffffc0000000000 R14: 000000000008a3f4 R15: ffffc90002c5f5c0
FS:  00007f667c032700(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000c015e3b870 CR3: 000000007c11b000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 mem_cgroup_charge include/linux/memcontrol.h:665 [inline]
 __filemap_add_folio+0xa9a/0xe50 mm/filemap.c:857
 filemap_add_folio+0x106/0x2b0 mm/filemap.c:950
 do_read_cache_folio+0x207/0x820 mm/filemap.c:3475
 do_read_cache_page+0x30/0x150 mm/filemap.c:3567
 read_mapping_page include/linux/pagemap.h:641 [inline]
 dir_get_page fs/minix/dir.c:70 [inline]
 minix_find_entry+0x1a8/0x560 fs/minix/dir.c:170
 minix_inode_by_name+0x9a/0x240 fs/minix/dir.c:454
 minix_lookup+0xbf/0x150 fs/minix/namei.c:30
 __lookup_slow+0x27f/0x3d0 fs/namei.c:1707
 lookup_slow fs/namei.c:1724 [inline]
 walk_component+0x516/0x790 fs/namei.c:2020
 lookup_last fs/namei.c:2475 [inline]
 path_lookupat+0x19d/0x6c0 fs/namei.c:2499
 filename_lookup+0x270/0x640 fs/namei.c:2528
 user_path_at_empty+0x40/0x1a0 fs/namei.c:2851
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:490 [inline]
 __se_sys_chdir+0xa4/0x2a0 fs/open.c:484
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f667d762059
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f667c032168 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 00007f667d875370 RCX: 00007f667d762059
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00007f667d7bc08d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcd2c4e7af R14: 00007f667c032300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	84 00                	test   %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	0f 1f 40 00          	nopl   0x0(%rax)
   a:	be 0d 00 00 00       	mov    $0xd,%esi
   f:	48 c7 c7 e0 b1 b5 8c 	mov    $0xffffffff8cb5b1e0,%rdi
  16:	e8 6f 97 4b 00       	callq  0x4b978a
  1b:	c3                   	retq
  1c:	cc                   	int3
  1d:	cc                   	int3
  1e:	cc                   	int3
  1f:	cc                   	int3
  20:	cc                   	int3
  21:	cc                   	int3
  22:	cc                   	int3
  23:	cc                   	int3
  24:	cc                   	int3
  25:	cc                   	int3
  26:	cc                   	int3
  27:	cc                   	int3
  28:	cc                   	int3
  29:	cc                   	int3
* 2a:	48 8b 04 24          	mov    (%rsp),%rax <-- trapping instruction
  2e:	65 48 8b 0c 25 80 6f 	mov    %gs:0x26f80,%rcx
  35:	02 00
  37:	65 8b 15 e4 c1 7c 7e 	mov    %gs:0x7e7cc1e4(%rip),%edx        # 0x7e7cc222
  3e:	f7                   	.byte 0xf7
  3f:	c2                   	.byte 0xc2

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2022/02/07 10:30 upstream d8ad2ce873ab a7dab638 .config log report info INFO: task hung in do_rmdir
* Struck through repros no longer work on HEAD.