syzbot


INFO: task hung in walk_component

Status: auto-closed as invalid on 2021/07/04 02:47
Reported-by: syzbot+d7b3c135a48666420881@syzkaller.appspotmail.com
First crash: 1086d, last: 1086d
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in walk_component (5) fuse C inconclusive 18 36d 551d 0/26 upstream: reported C repro on 2022/08/22 12:38
upstream INFO: task hung in walk_component (3) fs 9 805d 975d 0/26 closed as invalid on 2022/02/07 19:19
linux-4.19 INFO: task hung in walk_component (2) 2 875d 929d 0/1 auto-closed as invalid on 2022/01/31 04:51
upstream INFO: task hung in walk_component (2) fuse 31 1079d 1079d 20/26 fixed on 2021/04/09 19:46
upstream INFO: task hung in walk_component (4) fs 4 715d 738d 0/26 auto-closed as invalid on 2022/06/09 10:18
android-44 INFO: task hung in walk_component 1 1762d 1762d 0/2 auto-closed as invalid on 2019/10/25 08:50
linux-4.19 INFO: task hung in walk_component (3) f2fs C error 5 421d 570d 0/1 upstream: reported C repro on 2022/08/03 09:11
upstream INFO: task hung in walk_component fuse 1 2052d 2052d 0/26 closed as invalid on 2018/09/05 12:51

Sample crash report:
attempt to access beyond end of device
loop0: rw=0, want=308, limit=272
ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
batman_adv: batadv0: Interface deactivated: batadv_slave_0
INFO: task syz-executor.2:18464 blocked for more than 140 seconds.
      Not tainted 4.19.178-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
batman_adv: batadv0: Removing interface: batadv_slave_0
syz-executor.2  D28816 18464   8124 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_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
 lookup_last fs/namei.c:2274 [inline]
 path_lookupat+0x1ff/0x8d0 fs/namei.c:2319
 filename_lookup+0x1ac/0x5a0 fs/namei.c:2349
 user_path_at include/linux/namei.h:57 [inline]
 ksys_chdir+0x84/0x1d0 fs/open.c:458
 __do_sys_chdir fs/open.c:480 [inline]
 __se_sys_chdir fs/open.c:478 [inline]
 __x64_sys_chdir+0x2d/0x40 fs/open.c:478
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x465f69
Code: Bad RIP value.
RSP: 002b:00007fdbe2fed188 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 000000000056c0b0 RCX: 0000000000465f69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040
RBP: 00000000004bfa67 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0b0
R13: 00007fff699e744f R14: 00007fdbe2fed300 R15: 0000000000022000
batman_adv: batadv0: Interface deactivated: batadv_slave_1
batman_adv: batadv0: Removing interface: batadv_slave_1
INFO: task syz-executor.2:18470 blocked for more than 140 seconds.
      Not tainted 4.19.178-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D30344 18470   8124 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_nested+0x51/0x90 kernel/locking/rwsem.c:194
 inode_lock_nested include/linux/fs.h:783 [inline]
 filename_create+0x15a/0x490 fs/namei.c:3638
 user_path_create fs/namei.c:3696 [inline]
 do_mkdirat+0xa0/0x2d0 fs/namei.c:3834
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x465f69
Code: Bad RIP value.
RSP: 002b:00007fdbe2fcc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 000000000056c158 RCX: 0000000000465f69
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180
RBP: 00000000004bfa67 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c158
R13: 00007fff699e744f R14: 00007fdbe2fcc300 R15: 0000000000022000

Showing all locks held in the system:
device bridge_slave_1 left promiscuous mode
7 locks held by kworker/u4:1/23:
1 lock held by khungtaskd/1566:
 #0: 00000000199ec62f (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440
1 lock held by in:imklog/7795:
bridge0: port 2(bridge_slave_1) entered disabled state
 #0: 000000002838c162 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
2 locks held by kworker/1:3/8761:
 #0: 00000000cf191df1 ((wq_completion)"rcu_gp"){+.+.}, at: process_one_work+0x767/0x1570 kernel/workqueue.c:2123
 #1: 000000008b9b4737 ((work_completion)(&rew.rew_work)){+.+.}, at: process_one_work+0x79c/0x1570 kernel/workqueue.c:2127
2 locks held by syz-executor.2/18385:
1 lock held by syz-executor.2/18464:
 #0: 00000000ba27979d (&type->i_mutex_dir_key#9){++++}, at: inode_lock_shared include/linux/fs.h:758 [inline]
 #0: 00000000ba27979d (&type->i_mutex_dir_key#9){++++}, at: lookup_slow fs/namei.c:1688 [inline]
 #0: 00000000ba27979d (&type->i_mutex_dir_key#9){++++}, at: walk_component+0x798/0xda0 fs/namei.c:1811
2 locks held by syz-executor.2/18470:
 #0: 00000000b0772776 (sb_writers#14){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
 #0: 00000000b0772776 (sb_writers#14){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
 #1: 00000000ba27979d (&type->i_mutex_dir_key#8/1){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline]
 #1: 00000000ba27979d (&type->i_mutex_dir_key#8/1){+.+.}, at: filename_create+0x15a/0x490 fs/namei.c:3638

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

device bridge_slave_0 left promiscuous mode
NMI backtrace for cpu 0
CPU: 0 PID: 1566 Comm: khungtaskd Not tainted 4.19.178-syzkaller #0
bridge0: port 1(bridge_slave_0) entered disabled state
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8761 Comm: kworker/1:3 Not tainted 4.19.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue:            (null) (rcu_gp)
RIP: 0010:rcu_read_lock_sched_held+0xe1/0x1d0 kernel/rcu/update.c:117
Code: 8b 95 84 08 00 00 85 d2 75 b4 e8 0a da 00 00 84 c0 0f 84 88 00 00 00 e8 3d 8c 00 00 84 c0 74 7f 48 b8 00 00 00 00 00 fc ff df <48> 89 da 83 e3 07 48 c1 ea 03 83 c3 03 0f b6 04 02 38 c3 7c 08 84
RSP: 0018:ffff88804ef37cc0 EFLAGS: 00000002
RAX: dffffc0000000000 RBX: ffffffff8a45d0e0 RCX: 0000000000000000
RDX: 0000000000000004 RSI: ffffffff8375bba1 RDI: 0000000000000001
RBP: ffff88804ef78600 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffff88804ef78600
R13: 000000000002b040 R14: ffff88804ef30000 R15: ffff8880ba12b040
FS:  0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000130 CR3: 0000000093c41000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 trace_rcu_utilization include/trace/events/rcu.h:21 [inline]
 rcu_note_context_switch+0xc77/0x1690 kernel/rcu/tree.c:435
 __schedule+0x1f1/0x2040 kernel/sched/core.c:3445
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 worker_thread+0x14c/0x1130 kernel/workqueue.c:2316
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2021/03/06 02:46 linux-4.19.y dfb571610ba3 4a024a9b .config console log report info ci2-linux-4-19 INFO: task hung in walk_component
* Struck through repros no longer work on HEAD.