syzbot


INFO: task hung in walk_component (3)

Status: upstream: reported C repro on 2022/08/03 09:11
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+e3b74b156b3d7b7b5399@syzkaller.appspotmail.com
First crash: 604d, last: 454d
Fix bisection: failed (error log, bisect log)
  
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in walk_component 1 1119d 1119d 0/1 auto-closed as invalid on 2021/07/04 02:47
upstream INFO: task hung in walk_component (5) fuse C inconclusive 19 5d19h 584d 0/26 upstream: reported C repro on 2022/08/22 12:38
upstream INFO: task hung in walk_component (3) fs 9 838d 1009d 0/26 closed as invalid on 2022/02/07 19:19
linux-4.19 INFO: task hung in walk_component (2) 2 908d 962d 0/1 auto-closed as invalid on 2022/01/31 04:51
upstream INFO: task hung in walk_component (2) fuse 31 1112d 1113d 20/26 fixed on 2021/04/09 19:46
upstream INFO: task hung in walk_component (4) fs 4 749d 772d 0/26 auto-closed as invalid on 2022/06/09 10:18
android-44 INFO: task hung in walk_component 1 1796d 1795d 0/2 auto-closed as invalid on 2019/10/25 08:50
upstream INFO: task hung in walk_component fuse 1 2085d 2085d 0/26 closed as invalid on 2018/09/05 12:51

Sample crash report:
IPVS: ftp: loaded support on port[0] = 21
INFO: task syz-executor137:8101 blocked for more than 140 seconds.
      Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor137 D27840  8101   8100 0x00000000
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309
 call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 down_read+0x44/0x80 kernel/locking/rwsem.c:26
 inode_lock_shared include/linux/fs.h:758 [inline]
 lookup_slow fs/namei.c:1688 [inline]
 walk_component+0x798/0xda0 fs/namei.c:1811
 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142
 link_path_walk fs/namei.c:2073 [inline]
 path_openat+0x1db/0x2df0 fs/namei.c:3536
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f8360ca9648
Code: Bad RIP value.
RSP: 002b:00007ffd14f3b750 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffd14f3b7c0 RCX: 00007f8360ca9648
RDX: 0000000000090800 RSI: 00007f8360cfb004 RDI: 00000000ffffff9c
RBP: 0000000000000002 R08: 0000000000090800 R09: 00007f8360cfb004
R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffd14f3b94c
R13: 0000000000000002 R14: 00007ffd14f3b9a0 R15: 00007ffd14f3b990
INFO: task syz-executor137:8124 blocked for more than 140 seconds.
      Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor137 D27176  8124   8101 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 request_wait_answer+0x3dc/0x750 fs/fuse/dev.c:485
 __fuse_request_send+0x123/0x1c0 fs/fuse/dev.c:505
 fuse_simple_request+0x2e6/0x820 fs/fuse/dev.c:576
 fuse_lookup_name+0x24c/0x5c0 fs/fuse/dir.c:330
 fuse_lookup+0xdf/0x410 fs/fuse/dir.c:368
 __lookup_slow+0x246/0x4a0 fs/namei.c:1672
 lookup_slow fs/namei.c:1689 [inline]
 walk_component+0x7ac/0xda0 fs/namei.c:1811
 link_path_walk.part.0+0x901/0x1230 fs/namei.c:2142
 link_path_walk fs/namei.c:2073 [inline]
 path_openat+0x1db/0x2df0 fs/namei.c:3536
 do_filp_open+0x18c/0x3f0 fs/namei.c:3567
 do_sys_open+0x3b3/0x520 fs/open.c:1085
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f8360c661b4
Code: Bad RIP value.
RSP: 002b:00007f8360c55e60 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f8360c661b4
RDX: 0000000000004000 RSI: 00007f8360c55ee0 RDI: 00000000ffffff9c
RBP: 00007f8360c55ee0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000004000
R13: 0000000000000065 R14: 00007f8360cfd1e8 R15: 00007f8360d304c8
INFO: task syz-executor137:8127 blocked for more than 140 seconds.
      Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor137 D28800  8127   8101 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
 rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618
 call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
 __down_write arch/x86/include/asm/rwsem.h:142 [inline]
 down_write+0x4f/0x90 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:748 [inline]
 fuse_reverse_inval_entry+0xaa/0x660 fs/fuse/dir.c:987
 fuse_notify_delete fs/fuse/dev.c:1585 [inline]
 fuse_notify fs/fuse/dev.c:1819 [inline]
 fuse_dev_do_write+0x239e/0x2bc0 fs/fuse/dev.c:1894
 fuse_dev_write+0x153/0x1e0 fs/fuse/dev.c:1978
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x51b/0x770 fs/read_write.c:487
 vfs_write+0x1f3/0x540 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f8360ca99b9
Code: Bad RIP value.
RSP: 002b:00007f8360c352f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f8360d304d0 RCX: 00007f8360ca99b9
RDX: 000000000000002c RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00007f8360cfd1c4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 0000000000000003 R14: 00007f8360cfd1e8 R15: 00007f8360d304d8

Showing all locks held in the system:
1 lock held by khungtaskd/1570:
 #0: 00000000ed155f32 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by in:imklog/7845:
 #0: 00000000aa5aee0f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
1 lock held by syz-executor137/8101:
 #0: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline]
 #0: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: lookup_slow fs/namei.c:1688 [inline]
 #0: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: walk_component+0x798/0xda0 fs/namei.c:1811
2 locks held by syz-executor137/8124:
 #0: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline]
 #0: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: lookup_slow fs/namei.c:1688 [inline]
 #0: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: walk_component+0x798/0xda0 fs/namei.c:1811
 #1: 00000000d874ce5b (&fi->mutex){+.+.}, at: fuse_lock_inode+0xaf/0xe0 fs/fuse/inode.c:365
2 locks held by syz-executor137/8127:
 #0: 00000000ccd3f5c9 (&fc->killsb){.+.+}, at: fuse_notify_delete fs/fuse/dev.c:1582 [inline]
 #0: 00000000ccd3f5c9 (&fc->killsb){.+.+}, at: fuse_notify fs/fuse/dev.c:1819 [inline]
 #0: 00000000ccd3f5c9 (&fc->killsb){.+.+}, at: fuse_dev_do_write+0x2343/0x2bc0 fs/fuse/dev.c:1894
 #1: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: inode_lock include/linux/fs.h:748 [inline]
 #1: 000000006ea6b4b7 (&type->i_mutex_dir_key#7){++++}, at: fuse_reverse_inval_entry+0xaa/0x660 fs/fuse/dir.c:987

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

NMI backtrace for cpu 1
CPU: 1 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x991/0xe60 kernel/hung_task.c:287
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4683 Comm: systemd-journal Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:do_syscall_64+0x37e/0x620 arch/x86/entry/common.c:297
Code: fa 48 c1 ea 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e d4 01 00 00 83 63 08 f9 0f 1f 44 00 00 e8 d9 0b 62 00 0f 00 2d 02 e4 5f 07 <48> 83 c4 08 5b 5d 41 5c 41 5d e9 c3 0b 62 00 e8 be 0b 62 00 48 b8
RSP: 0018:ffff8880a149ff28 EFLAGS: 000000d3
RAX: ffff8880a1490340 RBX: ffff8880a1490340 RCX: ffffffff81007956
RDX: 0000000000000000 RSI: ffffffff81007997 RDI: ffff8880a1490348
RBP: ffff8880a149ff58 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000100 R14: 0000000000000000 R15: 0000000000000000
FS:  00007ff0ba4818c0(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff0b785f008 CR3: 00000000a1ad4000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7ff0b9719f17
Code: ff ff ff 48 8b 4d a0 0f b7 51 fe 48 8b 4d a8 66 89 54 08 fe e9 1a ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 b8 27 00 00 00 0f 05 <c3> 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007ffe045a97d8 EFLAGS: 00000206 ORIG_RAX: 0000000000000027
RAX: 000000000000124b RBX: 0000560d8fccc1e0 RCX: 00007ff0b9719f17
RDX: 00007ffe045a9890 RSI: 0000000000000000 RDI: 0000560d8fccc1e0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000069 R11: 0000000000000206 R12: 00007ffe045a9890
R13: 000000000000124b R14: 00007ffe045ac680 R15: 00007ffe045a9c90

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/11/07 05:55 linux-4.19.y 3f8a27f9e27b 6d752409 .config console log report syz C [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in walk_component
2022/08/03 09:10 linux-4.19.y 3f8a27f9e27b 1c9013ac .config console log report syz C ci2-linux-4-19 INFO: task hung in walk_component
2022/12/30 15:58 linux-4.19.y 3f8a27f9e27b 44712fbc .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in walk_component
2022/12/30 01:48 linux-4.19.y 3f8a27f9e27b 44712fbc .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in walk_component
2022/11/17 11:02 linux-4.19.y 3f8a27f9e27b 3a127a31 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in walk_component
* Struck through repros no longer work on HEAD.