syzbot


INFO: task hung in d_alloc_parallel (2)

Status: auto-obsoleted due to no activity on 2025/06/23 01:24
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+55f124a35eac76b52fb7@syzkaller.appspotmail.com
First crash: 2167d, last: 104d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: INFO: task hung in lookup_slow (log)
Repro: C syz .config
  
Fix bisection: failed (error log, bisect log)
  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] Monthly fs report (Jul 2024) 0 (1) 2024/07/18 07:59
INFO: task hung in d_alloc_parallel (2) 0 (1) 2019/10/22 22:44
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in d_alloc_parallel (2) origin:lts-only C error 10 41d 234d 0/3 upstream: reported C repro on 2024/11/04 12:30
android-49 INFO: task hung in d_alloc_parallel 85 2116d 2266d 0/3 auto-closed as invalid on 2020/01/08 20:52
linux-5.15 INFO: task hung in d_alloc_parallel missing-backport origin:upstream C error 78 3d22h 435d 0/3 upstream: reported C repro on 2024/04/18 05:41
linux-4.14 INFO: task hung in d_alloc_parallel C error 4 1535d 2144d 0/1 upstream: reported C repro on 2019/08/14 00:43
android-414 INFO: task hung in d_alloc_parallel 1 2076d 2076d 0/1 auto-closed as invalid on 2020/02/18 04:29
linux-4.19 INFO: task hung in d_alloc_parallel vfs C error 5 865d 1882d 0/1 upstream: reported C repro on 2020/05/01 20:49
upstream INFO: task hung in d_alloc_parallel fuse 213 2309d 2641d 0/29 closed as dup on 2018/09/08 15:40
linux-6.1 INFO: task hung in d_alloc_parallel 43 315d 438d 0/3 auto-obsoleted due to no activity on 2024/10/24 17:53
Last patch testing requests (10)
Created Duration User Patch Repo Result
2025/06/23 00:43 21m retest repro upstream OK log
2025/06/23 00:43 19m retest repro upstream OK log
2025/06/22 06:28 32m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/06/22 01:18 24m retest repro linux-next OK log
2025/04/13 10:38 1h19m retest repro upstream report log
2025/04/13 10:38 16m retest repro upstream report log
2025/04/13 06:06 19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/04/12 23:49 18m retest repro linux-next report log
2025/02/02 03:42 15m retest repro upstream report log
2025/02/02 03:42 15m retest repro upstream report log

Sample crash report:
INFO: task syz-executor942:8475 blocked for more than 143 seconds.
      Not tainted 5.14.0-rc4-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor942 state:D stack:28984 pid: 8475 ppid:  8448 flags:0x00000004
Call Trace:
 context_switch kernel/sched/core.c:4683 [inline]
 __schedule+0x93a/0x26f0 kernel/sched/core.c:5940
 schedule+0xd3/0x270 kernel/sched/core.c:6019
 d_wait_lookup fs/dcache.c:2562 [inline]
 d_alloc_parallel+0x105b/0x19f0 fs/dcache.c:2644
 __lookup_slow+0x193/0x480 fs/namei.c:1631
 lookup_slow fs/namei.c:1663 [inline]
 walk_component+0x40f/0x6a0 fs/namei.c:1959
 lookup_last fs/namei.c:2414 [inline]
 path_lookupat+0x1bb/0x860 fs/namei.c:2438
 filename_lookup+0x1c6/0x5b0 fs/namei.c:2467
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:493 [inline]
 __se_sys_chdir fs/open.c:487 [inline]
 __x64_sys_chdir+0xb7/0x260 fs/open.c:487
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x44aab9
RSP: 002b:00007f8f216cd2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 00000000004cc4e0 RCX: 000000000044aab9
RDX: 00007f8f216cd700 RSI: c8d0f6fefea0521c RDI: 0000000020000040
RBP: 000000000049b0b0 R08: 00007f8f216cd700 R09: 0000000000000000
R10: 00007f8f216cd700 R11: 0000000000000246 R12: 00000000200011c0
R13: 0030656c69662f2e R14: 000000807fffffff R15: 00000000004cc4e8

Showing all locks held in the system:
1 lock held by khungtaskd/1632:
 #0: ffffffff8b979000 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446
6 locks held by kswapd0/2143:
1 lock held by in:imklog/8146:
 #0: ffff8880164aadf0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:974
1 lock held by syz-executor942/8465:
1 lock held by syz-executor942/8468:
1 lock held by syz-executor942/8470:
1 lock held by syz-executor942/8466:
2 locks held by syz-executor942/8460:
1 lock held by syz-executor942/8475:
 #0: ffff8880414a0210 (&type->i_mutex_dir_key#7){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:784 [inline]
 #0: ffff8880414a0210 (&type->i_mutex_dir_key#7){.+.+}-{3:3}, at: lookup_slow fs/namei.c:1662 [inline]
 #0: ffff8880414a0210 (&type->i_mutex_dir_key#7){.+.+}-{3:3}, at: walk_component+0x400/0x6a0 fs/namei.c:1959
1 lock held by syz-executor942/8473:

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

NMI backtrace for cpu 1
CPU: 1 PID: 1632 Comm: khungtaskd Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
 watchdog+0xd0a/0xfc0 kernel/hung_task.c:295
 kthread+0x3e5/0x4d0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 8466 Comm: syz-executor942 Not tainted 5.14.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:mapping_get_entry mm/filemap.c:1778 [inline]
RIP: 0010:pagecache_get_page+0x19f/0x18d0 mm/filemap.c:1839
Code: 48 81 fd 02 04 00 00 74 cc e8 dd 83 db ff 48 85 ed 0f 84 68 0c 00 00 e8 cf 83 db ff 41 89 ee 31 ff 41 83 e6 01 48 89 6c 24 20 <44> 89 f6 e8 69 8b db ff 45 84 f6 0f 85 5d 0c 00 00 e8 ab 83 db ff
RSP: 0018:ffffc900018f7398 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffff88802ed1c2c0 RSI: ffffffff81994d01 RDI: 0000000000000000
RBP: ffffea000183a840 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffff83f42f86 R11: 0000000000000000 R12: 0000000000000002
R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000007
FS:  00007f8f216ee700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbb54cb9028 CR3: 000000003a9c8000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grow_dev_page fs/buffer.c:949 [inline]
 grow_buffers fs/buffer.c:1014 [inline]
 __getblk_slow+0x217/0xb70 fs/buffer.c:1041
 __getblk_gfp fs/buffer.c:1334 [inline]
 __bread_gfp+0x275/0x3c0 fs/buffer.c:1379
 sb_bread include/linux/buffer_head.h:303 [inline]
 get_branch fs/minix/itree_common.c:46 [inline]
 get_block+0x293/0x1450 fs/minix/itree_common.c:166
 minix_get_block+0xbb/0x110 fs/minix/inode.c:397
 block_read_full_page+0x28d/0xdf0 fs/buffer.c:2284
 do_read_cache_page+0x8e8/0x13c0 mm/filemap.c:3348
 read_mapping_page include/linux/pagemap.h:515 [inline]
 dir_get_page fs/minix/dir.c:70 [inline]
 minix_find_entry+0x203/0x7e0 fs/minix/dir.c:170
 minix_inode_by_name+0x6d/0x460 fs/minix/dir.c:454
 minix_lookup fs/minix/namei.c:30 [inline]
 minix_lookup+0x103/0x190 fs/minix/namei.c:22
 __lookup_slow+0x24c/0x480 fs/namei.c:1646
 lookup_slow fs/namei.c:1663 [inline]
 walk_component+0x40f/0x6a0 fs/namei.c:1959
 lookup_last fs/namei.c:2414 [inline]
 path_lookupat+0x1bb/0x860 fs/namei.c:2438
 filename_lookup+0x1c6/0x5b0 fs/namei.c:2467
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:493 [inline]
 __se_sys_chdir fs/open.c:487 [inline]
 __x64_sys_chdir+0xb7/0x260 fs/open.c:487
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x44aab9
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:00007f8f216ee2f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 00000000004cc4d0 RCX: 000000000044aab9
RDX: 00007f8f216ee700 RSI: c8d0f6fa9ea0521c RDI: 0000000020000040
RBP: 000000000049b0b0 R08: 00007f8f216ee700 R09: 0000000000000000
R10: 00007f8f216ee700 R11: 0000000000000246 R12: 00000000200011c0
R13: 0030656c69662f2e R14: 000000807fffffff R15: 00000000004cc4d8
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.006 msecs

Crashes (1411):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/08/03 06:59 upstream c500bee1c5b2 6c236867 .config console log report syz C ci-upstream-kasan-gce-selinux-root INFO: task hung in d_alloc_parallel
2019/10/20 00:35 upstream 998d75510e37 8c88c9c1 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2025/03/10 07:53 upstream 80e54e84911a 163f510d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2025/02/25 18:29 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/02/21 15:23 upstream 27eddbf34490 0808a665 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/02/02 13:29 upstream 69b8923f5003 568559e4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2025/01/18 14:07 upstream 595523945be0 f2cb035c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/07 21:34 upstream fbfd64d25c7a f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/04 18:24 upstream 63676eefb7a0 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/01 08:21 upstream ccb98ccef0e5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2025/01/01 07:19 upstream ccb98ccef0e5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/21 18:32 upstream 499551201b5f d7f584ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/16 14:44 upstream 78d4f34e2115 eec85da6 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/12/16 03:49 upstream dccbe2047a5b 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/08 06:23 upstream 7503345ac5f5 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/12/06 15:10 upstream b8f52214c61a 946d28f0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/12/06 05:06 upstream 5076001689e4 29f61fce .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/12/04 07:50 upstream ceb8bf2ceaa7 b50eb251 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/01 23:38 upstream bcc8eda6d349 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/01 08:46 upstream bcc8eda6d349 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/11/30 09:49 upstream 509f806f7f70 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/11/30 00:33 upstream 509f806f7f70 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/11/29 12:37 upstream 7af08b57bcb9 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/11/29 10:26 upstream 7af08b57bcb9 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/11/29 09:14 upstream 7af08b57bcb9 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/11/28 05:30 upstream aaf20f870da0 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/11/27 16:32 upstream 798bb342e041 52b38cc1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/08/30 14:45 upstream 20371ba12063 ee2602b8 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in d_alloc_parallel
2024/06/24 05:56 upstream 7c16f0a4ed1c edc5149a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in d_alloc_parallel
2024/05/19 01:32 upstream 4b377b4868ef c0f1611a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in d_alloc_parallel
2021/03/04 18:36 upstream f69d02e37a85 d7e4e604 .config console log report info ci-upstream-kasan-gce INFO: task hung in d_alloc_parallel
2021/02/11 23:05 upstream 291009f656e8 a5f86b15 .config console log report info ci-upstream-kasan-gce-386 INFO: task hung in d_alloc_parallel
2025/02/17 03:51 linux-next 0ae0fa3bf0b4 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/02/05 10:43 linux-next ed88b8b82c53 5896748e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/13 03:14 linux-next 7b4b9bf203da 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/11 19:08 linux-next 7b4b9bf203da 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/05 19:01 linux-next 8155b4ef3466 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/04 21:16 linux-next 8155b4ef3466 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/04 15:54 linux-next 8155b4ef3466 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/02 20:30 linux-next 8155b4ef3466 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/01/02 15:47 linux-next 8155b4ef3466 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/31 15:08 linux-next 8155b4ef3466 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/31 10:54 linux-next 8155b4ef3466 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/31 04:39 linux-next 8155b4ef3466 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/28 20:05 linux-next 8155b4ef3466 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/28 11:13 linux-next 8155b4ef3466 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/26 07:58 linux-next 8155b4ef3466 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/25 03:35 linux-next 8155b4ef3466 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/24 23:10 linux-next 8155b4ef3466 444551c4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/23 09:25 linux-next 8155b4ef3466 b4fbdbd4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/09 10:13 linux-next af2ea8ab7a54 9ac0fdc6 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/09 07:09 linux-next af2ea8ab7a54 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2024/12/07 18:27 linux-next af2ea8ab7a54 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in d_alloc_parallel
2025/03/15 06:26 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci a5618886fdab e2826670 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in d_alloc_parallel
2024/05/24 22:19 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci fda5695d692c 8f98448e .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 INFO: task hung in d_alloc_parallel
2021/01/15 05:57 upstream 146620506274 65a7a854 .config console log report info ci-upstream-kasan-gce-selinux-root
2019/07/21 13:08 upstream c6dd78fcb8ee 1656845f .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.