syzbot


INFO: task hung in lock_mount

Status: upstream: reported C repro on 2018/04/30 17:46
Reported-by: syzbot+221d75710bde87fa0e97@syzkaller.appspotmail.com
First crash: 1624d, last: 297d

Cause bisection: failed (bisect log)

Fix bisection: failed (bisect log)
duplicates (1):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
INFO: task can't die in lock_mount C 75 310d 648d 0/24 closed as dup on 2021/01/18 10:01
similar bugs (9):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in lock_mount (4) 6 317d 431d 0/1 auto-closed as invalid on 2022/03/15 09:18
android-49 INFO: task hung in lock_mount C 103 1149d 1266d 0/3 public: reported C repro on 2019/04/11 08:44
linux-4.19 INFO: task hung in lock_mount 5 992d 1123d 0/1 auto-closed as invalid on 2020/05/09 01:51
linux-4.19 INFO: task hung in lock_mount (2) 2 829d 836d 0/1 auto-closed as invalid on 2020/10/18 21:28
android-44 INFO: task hung in lock_mount C 4 1546d 1264d 0/2 public: reported C repro on 2019/04/13 00:00
linux-4.19 INFO: task hung in lock_mount (3) 1 596d 596d 0/1 auto-closed as invalid on 2021/06/09 16:09
linux-4.14 INFO: task hung in lock_mount 2 1024d 1025d 0/1 auto-closed as invalid on 2020/04/07 06:26
upstream INFO: task can't die in lock_mount C 75 310d 648d 0/24 closed as dup on 2021/01/18 10:01
upstream INFO: task can't die in iget5_locked 7 581d 605d 22/24 fixed on 2021/04/09 19:46
Patch testing requests:
Created Duration User Patch Repo Result
2022/09/22 17:29 22m https://github.com/google/kmsan.git master OK log
2022/09/11 23:27 19m upstream OK log

Sample crash report:
INFO: task syz-executor850:6551 blocked for more than 143 seconds.
      Not tainted 5.15.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor850 state:D stack:25584 pid: 6551 ppid:  6532 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xb72/0x1460 kernel/sched/core.c:6287
 schedule+0x14b/0x210 kernel/sched/core.c:6366
 rwsem_down_write_slowpath+0xdb7/0x1490 kernel/locking/rwsem.c:1107
 __down_write_common kernel/locking/rwsem.c:1262 [inline]
 __down_write kernel/locking/rwsem.c:1271 [inline]
 down_write+0x165/0x170 kernel/locking/rwsem.c:1518
 inode_lock include/linux/fs.h:786 [inline]
 lock_mount+0x6a/0x2f0 fs/namespace.c:2242
 do_new_mount_fc fs/namespace.c:2931 [inline]
 do_new_mount fs/namespace.c:2990 [inline]
 path_mount+0x22c7/0x2c30 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount+0x308/0x3c0 fs/namespace.c:3516
 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: 0033:0x7f1d36799a2a
RSP: 002b:00007f1d3673d078 EFLAGS: 00000286 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1d3673d0d0 RCX: 00007f1d36799a2a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007f1d3673d090
RBP: 0000000000000003 R08: 00007f1d3673d0d0 R09: 00007f1d3673d6bc
R10: 0000000000000000 R11: 0000000000000286 R12: 00007f1d3673d090
R13: 0000000020000248 R14: 0000000000000003 R15: 0000000000000004
INFO: task syz-executor850:6570 blocked for more than 144 seconds.
      Not tainted 5.15.0-rc5-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor850 state:D stack:27960 pid: 6570 ppid:  6532 flags:0x00004004
Call Trace:
 context_switch kernel/sched/core.c:4940 [inline]
 __schedule+0xb72/0x1460 kernel/sched/core.c:6287
 schedule+0x14b/0x210 kernel/sched/core.c:6366
 rwsem_down_read_slowpath+0x541/0x980 kernel/locking/rwsem.c:993
 __down_read_common+0xaa/0x450 kernel/locking/rwsem.c:1214
 inode_lock_shared include/linux/fs.h:796 [inline]
 lookup_slow fs/namei.c:1673 [inline]
 walk_component+0x508/0x790 fs/namei.c:1970
 lookup_last fs/namei.c:2425 [inline]
 path_lookupat+0x19d/0x6c0 fs/namei.c:2449
 filename_lookup+0x270/0x640 fs/namei.c:2478
 user_path_at_empty+0x40/0x1a0 fs/namei.c:2801
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:489 [inline]
 __se_sys_chdir+0xa4/0x2a0 fs/open.c:483
 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: 0033:0x7f1d36798599
RSP: 002b:00007f1d366fb208 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 00007f1d368153e8 RCX: 00007f1d36798599
RDX: 00007f1d366fb700 RSI: 405fa033c806de61 RDI: 0000000020000040
RBP: 00007f1d368153e0 R08: 00007f1d366fb700 R09: 0000000000000000
R10: 00007f1d366fb700 R11: 0000000000000246 R12: 00007f1d368153ec
R13: 00007ffee438344f R14: 00007f1d366fb300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c91c8c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by kswapd0/262:
1 lock held by kswapd1/263:
1 lock held by in:imklog/6211:
 #0: ffff888079dfa0f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:990
1 lock held by syz-executor850/6562:
1 lock held by syz-executor850/6557:
1 lock held by syz-executor850/6558:
1 lock held by syz-executor850/6563:
1 lock held by syz-executor850/6561:
1 lock held by syz-executor850/6551:
 #0: ffff88806af08c30 (&type->i_mutex_dir_key#7){++++}-{3:3}, at: inode_lock include/linux/fs.h:786 [inline]
 #0: ffff88806af08c30 (&type->i_mutex_dir_key#7){++++}-{3:3}, at: lock_mount+0x6a/0x2f0 fs/namespace.c:2242
1 lock held by syz-executor850/6570:
 #0: ffff88806af08c30 (&type->i_mutex_dir_key#7){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:796 [inline]
 #0: ffff88806af08c30 (&type->i_mutex_dir_key#7){++++}-{3:3}, at: lookup_slow fs/namei.c:1673 [inline]
 #0: ffff88806af08c30 (&type->i_mutex_dir_key#7){++++}-{3:3}, at: walk_component+0x508/0x790 fs/namei.c:1970

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-rc5-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+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105
 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:210 [inline]
 watchdog+0xc82/0xcd0 kernel/hung_task.c:295
 kthread+0x453/0x480 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6562 Comm: syz-executor850 Not tainted 5.15.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:validate_chain+0x0/0x8240 kernel/locking/lockdep.c:3745
Code: 48 c7 c1 98 39 dc 8d 80 e1 07 80 c1 03 38 c1 7c 81 48 c7 c7 98 39 dc 8d e8 fd 02 69 00 e9 70 ff ff ff e8 93 62 94 08 0f 1f 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 02
RSP: 0018:ffffc90002e8ef58 EFLAGS: 00000082
RAX: 1ffffffff1ed07c4 RBX: 00000000000002c4 RCX: e511bf3370b91992
RDX: 0000000000000000 RSI: ffff88801d2526c8 RDI: ffff88801d251c80
RBP: ffffc90002e8f0b0 R08: dffffc0000000000 R09: fffffbfff1fa37e4
R10: fffffbfff1fa37e4 R11: 0000000000000000 R12: ffff88801d251c80
R13: ffff88801d2526c8 R14: ffffffff8f683e20 R15: e511bf3370b91992
FS:  00007f1d3671c700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f59e0609b04 CR3: 0000000072681000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __lock_acquire+0x1382/0x2b00 kernel/locking/lockdep.c:5015
 lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5625
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:363 [inline]
 __find_get_block_slow+0xdf/0x6e0 fs/buffer.c:206
 __find_get_block+0x37d/0xc60 fs/buffer.c:1308
 __getblk_slow fs/buffer.c:1037 [inline]
 __getblk_gfp+0x13e/0x2d0 fs/buffer.c:1334
 __bread_gfp+0x2a/0x370 fs/buffer.c:1379
 sb_bread include/linux/buffer_head.h:303 [inline]
 get_branch fs/minix/itree_common.c:46 [inline]
 get_block+0x2ea/0x14b0 fs/minix/itree_common.c:166
 block_read_full_page+0x2d8/0xd80 fs/buffer.c:2288
 do_read_cache_page+0xb01/0xe10 mm/filemap.c:3458
 read_mapping_page include/linux/pagemap.h:515 [inline]
 dir_get_page fs/minix/dir.c:70 [inline]
 minix_find_entry+0x1a7/0x730 fs/minix/dir.c:170
 minix_inode_by_name+0x94/0x420 fs/minix/dir.c:454
 minix_lookup+0xbf/0x150 fs/minix/namei.c:30
 __lookup_slow+0x27f/0x3d0 fs/namei.c:1657
 lookup_slow fs/namei.c:1674 [inline]
 walk_component+0x516/0x790 fs/namei.c:1970
 lookup_last fs/namei.c:2425 [inline]
 path_lookupat+0x19d/0x6c0 fs/namei.c:2449
 filename_lookup+0x270/0x640 fs/namei.c:2478
 user_path_at_empty+0x40/0x1a0 fs/namei.c:2801
 user_path_at include/linux/namei.h:57 [inline]
 __do_sys_chdir fs/open.c:489 [inline]
 __se_sys_chdir+0xa4/0x2a0 fs/open.c:483
 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: 0033:0x7f1d36798599
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1d3671c208 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 00007f1d368153d8 RCX: 00007f1d36798599
RDX: 00007f1d3671c700 RSI: 405fa00f2806de61 RDI: 0000000020000040
RBP: 00007f1d368153d0 R08: 00007f1d3671c700 R09: 0000000000000000
R10: 00007f1d3671c700 R11: 0000000000000246 R12: 00007f1d368153dc
R13: 00007ffee438344f R14: 00007f1d3671c300 R15: 0000000000022000
----------------
Code disassembly (best guess):
   0:	48 c7 c1 98 39 dc 8d 	mov    $0xffffffff8ddc3998,%rcx
   7:	80 e1 07             	and    $0x7,%cl
   a:	80 c1 03             	add    $0x3,%cl
   d:	38 c1                	cmp    %al,%cl
   f:	7c 81                	jl     0xffffff92
  11:	48 c7 c7 98 39 dc 8d 	mov    $0xffffffff8ddc3998,%rdi
  18:	e8 fd 02 69 00       	callq  0x69031a
  1d:	e9 70 ff ff ff       	jmpq   0xffffff92
  22:	e8 93 62 94 08       	callq  0x89462ba
  27:	0f 1f 00             	nopl   (%rax)
* 2a:	55                   	push   %rbp <-- trapping instruction
  2b:	48 89 e5             	mov    %rsp,%rbp
  2e:	41 57                	push   %r15
  30:	41 56                	push   %r14
  32:	41 55                	push   %r13
  34:	41 54                	push   %r12
  36:	53                   	push   %rbx
  37:	48 83 e4 e0          	and    $0xffffffffffffffe0,%rsp
  3b:	48                   	rex.W
  3c:	81                   	.byte 0x81
  3d:	ec                   	in     (%dx),%al
  3e:	e0 02                	loopne 0x42

Crashes (1232):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2021/10/16 01:39 upstream ec681c53f8d2 0c5d9412 .config log report syz C INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2018/05/23 19:12 upstream a048a07d7f45 f48c20b8 .config log report syz C
ci-upstream-kasan-gce-root 2021/02/08 11:11 upstream b75dba7f472c 2ce644fc .config log report syz INFO: task hung in lock_mount
ci-upstream-kasan-gce-386 2018/06/18 05:27 upstream ce397d215ccd 27c5f59f .config log report syz C
ci-upstream-kmsan-gce 2018/08/19 06:02 https://github.com/google/kmsan.git master 0cc51dc9a291 de20bcbb .config log report syz C
ci-upstream-kasan-gce-root 2021/12/05 01:18 upstream bbef3c7a63d2 a617004c .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/12/02 19:46 upstream 58e1100fdc59 61f86278 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/11/18 08:25 upstream ee1703cda8dc cafff8b6 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/11/14 07:19 upstream ccfff0a2bd2a 83f5c9b5 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-smack-root 2021/11/09 07:23 upstream e851dfae4371 8ab17e57 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/11/06 04:14 upstream d4439a1189f9 4c1be0be .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/08/31 01:40 upstream 7d2a07b76933 8f58a0ef .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/16 02:06 upstream 1e28eed17697 fdb2bb2c .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/15 19:46 upstream 1e28eed17697 fdb2bb2c .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/15 03:23 upstream 75013c6c52d8 cc1cff8f .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/14 11:03 upstream 88fe49249c99 4a003785 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/14 04:41 upstream 88fe49249c99 4a003785 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/13 14:37 upstream f296bfd5cd04 4a003785 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/12 09:22 upstream 28806e4d9b97 429d8a6b .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/12 01:13 upstream 28806e4d9b97 429d8a6b .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/11 14:53 upstream a74e6a014c9d c2ca1f2a .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/11 01:55 upstream 05a59d79793d 764067f3 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/10 11:18 upstream 144c79ef3353 26967e35 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-selinux-root 2021/03/09 18:21 upstream 144c79ef3353 09fbf400 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/09 08:32 upstream 144c79ef3353 09fbf400 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce 2021/03/08 21:38 upstream 144c79ef3353 09fbf400 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/07 22:28 upstream a38fd8748464 75506d9c .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/07 22:28 upstream a38fd8748464 75506d9c .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/07 20:29 upstream a38fd8748464 75506d9c .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/05 17:08 upstream 280d542f6ffa 9d751681 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce 2021/03/05 15:01 upstream 280d542f6ffa 9d751681 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-selinux-root 2021/03/05 10:29 upstream cee407c5cc42 9d751681 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce 2021/03/05 09:22 upstream cee407c5cc42 9d751681 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/03/05 09:01 upstream cee407c5cc42 9d751681 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-selinux-root 2021/03/04 18:35 upstream f69d02e37a85 d7e4e604 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-selinux-root 2021/03/04 01:56 upstream f69d02e37a85 06ed56cd .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-smack-root 2021/03/03 23:41 upstream f69d02e37a85 06ed56cd .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce 2021/03/03 18:48 upstream f69d02e37a85 06ed56cd .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce 2021/03/03 08:02 upstream 7a7fd0de4a98 e5b64d68 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-selinux-root 2021/03/02 20:37 upstream 7a7fd0de4a98 92ead296 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce 2021/03/02 05:46 upstream fe07bfda2fb9 183afb6c .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/02/28 00:17 upstream 5695e5161974 4c37c133 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-smack-root 2021/02/25 04:01 upstream 719bbd4a509f fcc6d71b .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce 2021/02/25 01:02 upstream 719bbd4a509f fcc6d71b .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-root 2021/02/24 23:18 upstream c03c21ba6f4e fcc6d71b .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-selinux-root 2021/02/24 15:04 upstream c03c21ba6f4e fcc6d71b .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-386 2021/03/05 16:07 upstream 280d542f6ffa 9d751681 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-386 2021/03/05 12:30 upstream 280d542f6ffa 9d751681 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-386 2021/03/03 21:09 upstream f69d02e37a85 06ed56cd .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-386 2021/03/03 08:00 upstream 7a7fd0de4a98 e5b64d68 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-386 2021/02/25 02:52 upstream 719bbd4a509f fcc6d71b .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-386 2021/02/23 07:49 upstream a99163e9e708 c26fb06b .config log report info INFO: task hung in lock_mount
ci-qemu2-arm64-compat 2021/02/07 06:25 upstream 825b5991a46e 0655e081 .config log report info INFO: task hung in lock_mount
ci-upstream-kasan-gce-selinux-root 2021/01/16 15:04 upstream 1d94330a437a 65a7a854 .config log report info
ci-upstream-kasan-gce-root 2018/04/18 16:23 upstream a27fc14219f2 52643b44 .config log report
ci-upstream-linux-next-kasan-gce-root 2019/10/19 17:12 linux-next c4b9850b3676 8c88c9c1 .config log report
* Struck through repros no longer work on HEAD.