syzbot


INFO: task hung in d_alloc_parallel (2)

Status: upstream: reported C repro on 2019/10/22 22:44
Reported-by: syzbot+55f124a35eac76b52fb7@syzkaller.appspotmail.com
First crash: 1162d, last: 2d13h

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 (bisect log)
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in d_alloc_parallel 85 1111d 1261d 0/3 auto-closed as invalid on 2020/01/08 20:52
linux-4.14 INFO: task hung in d_alloc_parallel C error 4 530d 1139d 0/1 upstream: reported C repro on 2019/08/14 00:43
android-414 INFO: task hung in d_alloc_parallel 1 1071d 1071d 0/1 auto-closed as invalid on 2020/02/18 04:29
linux-4.19 INFO: task hung in d_alloc_parallel C error 4 28d 877d 0/1 upstream: reported C repro on 2020/05/01 20:49
upstream INFO: task hung in d_alloc_parallel 213 1304d 1636d 0/24 closed as dup on 2018/09/08 15:40

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 (150):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2021/08/03 06:59 upstream c500bee1c5b2 6c236867 .config log report syz C INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2019/10/20 00:35 upstream 998d75510e37 8c88c9c1 .config log report syz C
ci2-upstream-fs 2022/09/23 21:18 upstream bf682942cd26 0042f2b4 .config log report info INFO: task hung in d_alloc_parallel
ci2-upstream-fs 2022/09/19 19:29 upstream 521a547ced64 dd9a85ff .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2022/09/15 18:42 upstream 3245cb65fd91 dd9a85ff .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-smack-root 2022/02/23 20:08 upstream 5c1ee569660d 6e821dbf .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2022/02/10 19:22 upstream e3c85076d7a6 0b33604d .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/10/03 04:00 upstream ab2a7a35c4e7 db0f5787 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/09/17 01:24 upstream ff1ffd71d5f0 aae492f2 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/03/15 19:52 upstream 1e28eed17697 fdb2bb2c .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/03/13 21:13 upstream f296bfd5cd04 4a003785 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/03/13 21:03 upstream f296bfd5cd04 4a003785 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/03/04 18:36 upstream f69d02e37a85 d7e4e604 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/02/22 13:33 upstream 31caf8b2a847 a659b3f1 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/02/20 21:56 upstream f40ddce88593 3e5ed8b4 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/02/17 11:40 upstream f40ddce88593 052f8d9f .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-smack-root 2021/02/17 10:37 upstream f40ddce88593 052f8d9f .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-smack-root 2021/02/16 22:35 upstream f40ddce88593 98682e5e .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/02/11 23:12 upstream 291009f656e8 a5f86b15 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/02/10 03:13 upstream e0756cfc7d7c 2bd9619f .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/02/10 00:30 upstream e0756cfc7d7c 2bd9619f .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/02/07 02:26 upstream 964d069f93c4 0655e081 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/02/04 22:49 upstream 61556703b610 42b90a7c .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/02/04 22:22 upstream 61556703b610 42b90a7c .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/02/03 20:44 upstream 3aaf0a27ffc2 624dad51 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/02/03 07:08 upstream 3aaf0a27ffc2 624dad51 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/02/03 02:43 upstream 3aaf0a27ffc2 624dad51 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/01/31 10:14 upstream 8c947645151c fc9fd31e .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/01/31 05:33 upstream 8c947645151c fc9fd31e .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/01/29 20:01 upstream bec4c2968fce 6593fd32 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-smack-root 2021/01/29 14:17 upstream bec4c2968fce 6593fd32 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/01/29 13:07 upstream bec4c2968fce 6593fd32 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/01/29 11:12 upstream bec4c2968fce 6593fd32 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/01/28 03:52 upstream 76c057c84d28 eefc07f2 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/01/27 04:26 upstream 13391c60da33 55a7d4df .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/01/26 21:47 upstream 13391c60da33 55a7d4df .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/01/23 19:01 upstream fe75a21824e7 52e37319 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce 2021/01/23 17:50 upstream fe75a21824e7 52e37319 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/01/22 12:21 upstream 9f29bd8b2e71 d4f4eca5 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/01/20 00:50 upstream 1e2a199f6ccd 63631df1 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-smack-root 2021/01/19 15:35 upstream 1e2a199f6ccd 63631df1 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-smack-root 2021/01/18 10:22 upstream a1339d6355ac fd103621 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/01/18 07:13 upstream a1339d6355ac fd103621 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-smack-root 2021/01/18 05:31 upstream a1339d6355ac fd103621 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-root 2021/01/18 04:09 upstream a1339d6355ac fd103621 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-386 2021/02/11 23:05 upstream 291009f656e8 a5f86b15 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-386 2021/02/10 17:53 upstream e0756cfc7d7c 2bd9619f .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-386 2021/02/05 17:35 upstream dd86e7fa07a3 23a562df .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-386 2021/02/04 14:52 upstream 61556703b610 42b90a7c .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-386 2021/02/03 15:59 upstream 3aaf0a27ffc2 624dad51 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-386 2021/01/19 13:36 upstream 1e2a199f6ccd 63631df1 .config log report info INFO: task hung in d_alloc_parallel
ci-upstream-kasan-gce-selinux-root 2021/01/15 05:57 upstream 146620506274 65a7a854 .config log report info
ci-upstream-kasan-gce-smack-root 2021/01/15 02:02 upstream 65f0d2414b70 65a7a854 .config log report info
ci-upstream-kasan-gce 2021/01/11 08:05 upstream 0653161f0fac 2c1f2513 .config log report info
ci-upstream-kasan-gce-selinux-root 2021/01/09 03:32 upstream 6279d812eab6 c104d4a3 .config log report info
ci-upstream-kasan-gce-smack-root 2019/07/21 13:08 upstream c6dd78fcb8ee 1656845f .config log report
ci-upstream-kasan-gce-386 2021/01/08 12:38 upstream f5e6c330254a c104d4a3 .config log report info
ci-upstream-kasan-gce-386 2021/01/08 12:38 upstream f5e6c330254a c104d4a3 .config log report info
ci-upstream-linux-next-kasan-gce-root 2019/09/16 02:12 linux-next 6d028043b55e 32d59357 .config log report
* Struck through repros no longer work on HEAD.