syzbot


INFO: task hung in do_rmdir

Status: upstream: reported C repro on 2024/12/02 03:09
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+49a471f4ff67c7c5776c@syzkaller.appspotmail.com
First crash: 19d, last: 19d
Bug presence (2)
Date Name Commit Repro Result
2024/12/02 linux-5.15.y (ToT) 0a51d2d4527b C [report] INFO: task hung in do_rmdir
2024/12/02 upstream (ToT) e70140ba0d2b C Didn't crash
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in do_rmdir (5) ext4 nilfs 5 708d 875d 0/28 auto-obsoleted due to no activity on 2023/04/25 17:21
upstream INFO: task hung in do_rmdir (3) fs 10 1389d 1464d 0/28 auto-closed as invalid on 2021/06/01 08:24
linux-4.19 INFO: task hung in do_rmdir 1 892d 892d 0/1 auto-obsoleted due to no activity on 2022/11/10 04:55
android-49 INFO: task hung in do_rmdir 1 2414d 2414d 0/3 auto-closed as invalid on 2019/02/22 12:59
upstream INFO: task hung in do_rmdir (4) fs 1 1048d 1048d 0/28 auto-closed as invalid on 2022/05/08 10:41
upstream INFO: task hung in do_rmdir (2) exfat 3 2172d 2307d 0/28 closed as dup on 2018/09/11 15:01
upstream INFO: task hung in do_rmdir (6) kernfs C error 35 13d 57d 0/28 upstream: reported C repro on 2024/10/25 00:44
upstream INFO: task hung in do_rmdir fs 1 2461d 2461d 0/28 closed as invalid on 2018/03/27 11:14

Sample crash report:
INFO: task syz-executor250:4189 blocked for more than 143 seconds.
      Not tainted 5.15.173-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor250 state:D stack:28624 pid: 4189 ppid:  4185 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5027 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
 inode_lock_nested include/linux/fs.h:824 [inline]
 do_rmdir+0x225/0x670 fs/namei.c:4197
 __do_sys_rmdir fs/namei.c:4229 [inline]
 __se_sys_rmdir fs/namei.c:4227 [inline]
 __x64_sys_rmdir+0x45/0x50 fs/namei.c:4227
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdbb5555789
RSP: 002b:00007fdbb54f1218 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007fdbb55dd6d8 RCX: 00007fdbb5555789
RDX: 00007fdbb552eef6 RSI: 0000000000000000 RDI: 00000000200000c0
RBP: 00007fdbb55dd6d0 R08: 00007ffec888bd47 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdbb55a907e
R13: 00007fdbb55a90e0 R14: 0030656c69662f2e R15: 0031656c69662f2e
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8cb1fc60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3931:
 #0: ffff88814c672098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
3 locks held by syz-executor250/4187:
2 locks held by syz-executor250/4189:
 #0: ffff88802b420460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
 #1: ffff8880757702b0 (&sb->s_type->i_mutex_key#15/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:824 [inline]
 #1: ffff8880757702b0 (&sb->s_type->i_mutex_key#15/1){+.+.}-{3:3}, at: do_rmdir+0x225/0x670 fs/namei.c:4197

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xe72/0xeb0 kernel/hung_task.c:295
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4187 Comm: syz-executor250 Not tainted 5.15.173-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:kasan_check_range+0x1ac/0x290 mm/kasan/generic.c:189
Code: 4c 89 d5 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 39 00 0f 85 a2 00 00 00 49 ff c1 48 ff cd 75 ee 5b <41> 5e 41 5f 5d c3 45 84 f6 75 61 41 f7 c6 00 ff 00 00 75 5d 41 f7
RSP: 0018:ffffc90002d8f338 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 00000000000006ae RCX: ffffffff81632d68
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff909881d0
RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff213103b
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802c2d0b38
R13: dffffc0000000000 R14: fffffbfff213103b R15: ffff88802c2d0b18
FS:  00007fdbb55126c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000561605d11600 CR3: 0000000027f7e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 hlock_class kernel/locking/lockdep.c:197 [inline]
 mark_lock+0x98/0x340 kernel/locking/lockdep.c:4569
 mark_held_locks kernel/locking/lockdep.c:4193 [inline]
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4211 [inline]
 lockdep_hardirqs_on_prepare+0x27d/0x7a0 kernel/locking/lockdep.c:4278
 trace_hardirqs_on+0x67/0x80 kernel/trace/trace_preemptirq.c:49
 lookup_bh_lru fs/buffer.c:1294 [inline]
 __find_get_block+0x2c4/0x1350 fs/buffer.c:1306
 __getblk_gfp+0x2d/0xaf0 fs/buffer.c:1332
 __bread_gfp+0x2a/0x390 fs/buffer.c:1381
 sb_bread include/linux/buffer_head.h:337 [inline]
 exfat_get_dentry+0x678/0x970 fs/exfat/dir.c:741
 exfat_readdir fs/exfat/dir.c:122 [inline]
 exfat_iterate+0xc09/0x34a0 fs/exfat/dir.c:258
 iterate_dir+0x224/0x570
 __do_sys_getdents fs/readdir.c:286 [inline]
 __se_sys_getdents+0x1e8/0x4c0 fs/readdir.c:271
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdbb5555789
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 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:00007fdbb5512218 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007fdbb55dd6c8 RCX: 00007fdbb5555789
RDX: 00000000000000b6 RSI: 0000000020001fc0 RDI: 0000000000000004
RBP: 00007fdbb55dd6c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdbb55a907e
R13: 00007fdbb55a90e0 R14: 0030656c69662f2e R15: 0031656c69662f2e
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 3.254 msecs

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/12/02 10:53 linux-5.15.y 0a51d2d4527b 68914665 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan INFO: task hung in do_rmdir
2024/12/02 08:49 linux-5.15.y 0a51d2d4527b 68914665 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan INFO: task hung in do_rmdir
2024/12/02 06:57 linux-5.15.y 0a51d2d4527b 68914665 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan INFO: task hung in do_rmdir
2024/12/02 05:02 linux-5.15.y 0a51d2d4527b 68914665 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan INFO: task hung in do_rmdir
2024/12/02 03:08 linux-5.15.y 0a51d2d4527b 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: task hung in do_rmdir
* Struck through repros no longer work on HEAD.