syzbot


INFO: task can't die in open_ctree

Status: auto-closed as invalid on 2022/01/03 05:22
Subsystems: btrfs
[Documentation on labels]
Reported-by: syzbot+7125ff56084ba521fcde@syzkaller.appspotmail.com
First crash: 901d, last: 901d

Sample crash report:
INFO: task syz-executor.5:23053 can't die for more than 143 seconds.
task:syz-executor.5  state:D stack:26192 pid:23053 ppid: 17804 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4984 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6265
 schedule+0xd2/0x260 kernel/sched/core.c:6338
 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x174/0x270 kernel/sched/completion.c:138
 kthread_stop+0x17a/0x710 kernel/kthread.c:648
 open_ctree+0x46d6/0x4954 fs/btrfs/disk-io.c:3669
 btrfs_fill_super fs/btrfs/super.c:1359 [inline]
 btrfs_mount_root.cold+0x15/0x162 fs/btrfs/super.c:1726
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1500
 fc_mount fs/namespace.c:994 [inline]
 vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1024
 vfs_kern_mount+0x3c/0x60 fs/namespace.c:1011
 btrfs_mount+0x234/0xa60 fs/btrfs/super.c:1786
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1500
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount fs/namespace.c:3516 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3516
 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: 0033:0x7fbf7005001a
RSP: 002b:00007fbf6d5c3fa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007fbf7005001a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fbf6d5c4000
RBP: 00007fbf6d5c4040 R08: 00007fbf6d5c4040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007fbf6d5c4000 R15: 0000000020016800
 </TASK>
INFO: task syz-executor.5:23053 blocked for more than 143 seconds.
      Not tainted 5.15.0-next-20211104-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:26192 pid:23053 ppid: 17804 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4984 [inline]
 __schedule+0xa9a/0x4940 kernel/sched/core.c:6265
 schedule+0xd2/0x260 kernel/sched/core.c:6338
 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common kernel/sched/completion.c:117 [inline]
 wait_for_completion+0x174/0x270 kernel/sched/completion.c:138
 kthread_stop+0x17a/0x710 kernel/kthread.c:648
 open_ctree+0x46d6/0x4954 fs/btrfs/disk-io.c:3669
 btrfs_fill_super fs/btrfs/super.c:1359 [inline]
 btrfs_mount_root.cold+0x15/0x162 fs/btrfs/super.c:1726
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1500
 fc_mount fs/namespace.c:994 [inline]
 vfs_kern_mount.part.0+0xd3/0x170 fs/namespace.c:1024
 vfs_kern_mount+0x3c/0x60 fs/namespace.c:1011
 btrfs_mount+0x234/0xa60 fs/btrfs/super.c:1786
 legacy_get_tree+0x105/0x220 fs/fs_context.c:610
 vfs_get_tree+0x89/0x2f0 fs/super.c:1500
 do_new_mount fs/namespace.c:2988 [inline]
 path_mount+0x1320/0x1fa0 fs/namespace.c:3318
 do_mount fs/namespace.c:3331 [inline]
 __do_sys_mount fs/namespace.c:3539 [inline]
 __se_sys_mount fs/namespace.c:3516 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3516
 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: 0033:0x7fbf7005001a
RSP: 002b:00007fbf6d5c3fa8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007fbf7005001a
RDX: 0000000020000000 RSI: 0000000020000100 RDI: 00007fbf6d5c4000
RBP: 00007fbf6d5c4040 R08: 00007fbf6d5c4040 R09: 0000000020000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000020000000
R13: 0000000020000100 R14: 00007fbf6d5c4000 R15: 0000000020016800
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8bb83a60 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458
1 lock held by in:imklog/6234:
1 lock held by systemd-udevd/22528:
1 lock held by syz-executor.5/23053:
 #0: ffff88801cb9a0e0 (&type->s_umount_key#90/1){+.+.}-{3:3}, at: alloc_super+0x1dd/0xac0 fs/super.c:229

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.0-next-20211104-syzkaller #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+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline]
 watchdog+0xcb7/0xed0 kernel/hung_task.c:339
 kthread+0x405/0x4f0 kernel/kthread.c:327
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 23136 Comm: systemd-udevd Not tainted 5.15.0-next-20211104-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:memset_erms+0xb/0x10 arch/x86/lib/memset_64.S:65
Code: 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3 aa <4c> 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01 01 01
RSP: 0018:ffffc90015ea7ac8 EFLAGS: 00000246
RAX: dffffc00000000fc RBX: ffff8880145f4000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 00000000000000fc RDI: ffffed10028bea00
RBP: 0000000000000c40 R08: 0000000000000c40 R09: ffffed10028bea00
R10: ffffc90015ea7a78 R11: 00000000ffffffff R12: ffff888010c42140
R13: 0000000000001000 R14: ffffc90015ea7be8 R15: 0000000000001000
FS:  00007fdd9afca8c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005618e4dcf128 CR3: 00000000312f4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ____kasan_kmalloc mm/kasan/common.c:505 [inline]
 ____kasan_kmalloc mm/kasan/common.c:472 [inline]
 __kasan_kmalloc+0x76/0xd0 mm/kasan/common.c:522
 kmalloc include/linux/slab.h:595 [inline]
 tomoyo_realpath_from_path+0xc3/0x620 security/tomoyo/realpath.c:254
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x21b/0x400 security/tomoyo/file.c:822
 security_inode_getattr+0xcf/0x140 security/security.c:1334
 vfs_getattr fs/stat.c:157 [inline]
 vfs_fstat+0x43/0xb0 fs/stat.c:182
 __do_sys_newfstat+0x81/0x100 fs/stat.c:422
 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: 0033:0x7fdd99e3c2e2
Code: 48 8b 05 b9 db 2b 00 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 83 ff 01 77 33 48 63 fe b8 05 00 00 00 48 89 d6 0f 05 <48> 3d 00 f0 ff ff 77 06 f3 c3 0f 1f 40 00 48 8b 15 81 db 2b 00 f7
RSP: 002b:00007fffed3106d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000005
RAX: ffffffffffffffda RBX: 00007fdd9a0f7440 RCX: 00007fdd99e3c2e2
RDX: 00007fffed3106e0 RSI: 00007fffed3106e0 RDI: 000000000000000f
RBP: 00005618e253feb0 R08: 0000000000000b40 R09: 00005618e2554650
R10: 00005618e253feb0 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000001000 R14: 00005618e2554650 R15: 00007fffed3109a0
 </TASK>
----------------
Code disassembly (best guess):
   0:	03 40 0f             	add    0xf(%rax),%eax
   3:	b6 f6                	mov    $0xf6,%dh
   5:	48 b8 01 01 01 01 01 	movabs $0x101010101010101,%rax
   c:	01 01 01
   f:	48 0f af c6          	imul   %rsi,%rax
  13:	f3 48 ab             	rep stos %rax,%es:(%rdi)
  16:	89 d1                	mov    %edx,%ecx
  18:	f3 aa                	rep stos %al,%es:(%rdi)
  1a:	4c 89 c8             	mov    %r9,%rax
  1d:	c3                   	retq
  1e:	90                   	nop
  1f:	49 89 f9             	mov    %rdi,%r9
  22:	40 88 f0             	mov    %sil,%al
  25:	48 89 d1             	mov    %rdx,%rcx
  28:	f3 aa                	rep stos %al,%es:(%rdi)
* 2a:	4c 89 c8             	mov    %r9,%rax <-- trapping instruction
  2d:	c3                   	retq
  2e:	90                   	nop
  2f:	49 89 fa             	mov    %rdi,%r10
  32:	40 0f b6 ce          	movzbl %sil,%ecx
  36:	48 b8 01 01 01 01 01 	movabs $0x101010101010101,%rax
  3d:	01 01 01

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/11/04 05:22 linux-next 8a796a1dfca2 4c1be0be .config console log report info ci-upstream-linux-next-kasan-gce-root INFO: task can't die in open_ctree
* Struck through repros no longer work on HEAD.