syzbot


INFO: task hung in kernfs_dop_revalidate (2)

Status: auto-obsoleted due to no activity on 2023/04/29 22:59
Subsystems: kernfs
[Documentation on labels]
First crash: 892d, last: 838d
Similar bugs (4)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in kernfs_dop_revalidate kernfs syz unreliable inconclusive 2 1034d 1060d 0/28 auto-obsoleted due to no activity on 2022/11/15 03:06
android-414 INFO: task hung in kernfs_dop_revalidate 1 2113d 2113d 0/1 auto-closed as invalid on 2019/12/01 15:25
upstream INFO: task hung in kernfs_dop_revalidate (4) kernfs C error 102 25d 346d 0/28 upstream: reported C repro on 2024/06/04 12:47
upstream INFO: task hung in kernfs_dop_revalidate (3) kernfs 1 561d 561d 0/28 auto-obsoleted due to no activity on 2024/01/31 18:27

Sample crash report:
INFO: task udevd:4428 blocked for more than 143 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd           state:D stack:24736 pid:4428  ppid:1      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_dop_revalidate+0xf0/0x5b0 fs/kernfs/dir.c:1130
 d_revalidate fs/namei.c:856 [inline]
 d_revalidate fs/namei.c:853 [inline]
 lookup_fast+0x22d/0x520 fs/namei.c:1646
 walk_component+0x5e/0x5a0 fs/namei.c:1989
 link_path_walk.part.0+0x730/0xdf0 fs/namei.c:2320
 link_path_walk fs/namei.c:2244 [inline]
 path_lookupat+0xb7/0x840 fs/namei.c:2473
 filename_lookup+0x1d2/0x590 fs/namei.c:2503
 vfs_statx+0x14c/0x430 fs/stat.c:232
 vfs_fstatat+0x90/0xb0 fs/stat.c:270
 __do_sys_newfstatat+0x94/0x120 fs/stat.c:440
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f20ead251da
RSP: 002b:00007ffc838a5138 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 0000561f40bcecc0 RCX: 00007f20ead251da
RDX: 00007ffc838a5148 RSI: 00007ffc838a55d8 RDI: 00000000ffffff9c
RBP: 00007ffc838a51d8 R08: 0000000000000000 R09: 0000561f40bd1160
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc838a55d8
R13: 00007ffc838a5148 R14: 0000561f40ba9910 R15: 0000000000000000
 </TASK>
INFO: task syz-executor.1:5091 blocked for more than 143 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.1  state:D stack:23600 pid:5091  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_find_and_get_ns+0x73/0xc0 fs/kernfs/dir.c:891
 kernfs_find_and_get include/linux/kernfs.h:597 [inline]
 sysfs_unmerge_group+0x61/0x170 fs/sysfs/group.c:365
 dpm_sysfs_remove+0x8c/0xb0 drivers/base/power/sysfs.c:836
 device_del+0x20f/0xc80 drivers/base/core.c:3643
 device_unregister+0x1e/0xc0 drivers/base/core.c:3698
 bdi_unregister+0x42d/0x600 mm/backing-dev.c:1072
 generic_shutdown_super+0x33d/0x410 fs/super.c:507
 kill_anon_super+0x3a/0x60 fs/super.c:1086
 btrfs_kill_super+0x3c/0x50 fs/btrfs/super.c:2132
 deactivate_locked_super+0x98/0x160 fs/super.c:332
 deactivate_super+0xb1/0xd0 fs/super.c:363
 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f0b6688d537
RSP: 002b:00007fff1a93dbc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f0b6688d537
RDX: 00007fff1a93dc9b RSI: 000000000000000a RDI: 00007fff1a93dc90
RBP: 00007fff1a93dc90 R08: 00000000ffffffff R09: 00007fff1a93da60
R10: 00005555570298b3 R11: 0000000000000246 R12: 00007f0b668e6b24
R13: 00007fff1a93ed50 R14: 0000555557029810 R15: 00007fff1a93ed90
 </TASK>
INFO: task syz-executor.0:5093 blocked for more than 144 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0  state:D stack:23184 pid:5093  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_find_and_get_ns+0x73/0xc0 fs/kernfs/dir.c:891
 kernfs_find_and_get include/linux/kernfs.h:597 [inline]
 sysfs_unmerge_group+0x61/0x170 fs/sysfs/group.c:365
 dpm_sysfs_remove+0x66/0xb0 drivers/base/power/sysfs.c:833
 device_del+0x20f/0xc80 drivers/base/core.c:3643
 device_unregister+0x1e/0xc0 drivers/base/core.c:3698
 bdi_unregister+0x42d/0x600 mm/backing-dev.c:1072
 generic_shutdown_super+0x33d/0x410 fs/super.c:507
 kill_anon_super+0x3a/0x60 fs/super.c:1086
 fuse_kill_sb_anon+0x1e3/0x330 fs/fuse/inode.c:1813
 deactivate_locked_super+0x98/0x160 fs/super.c:332
 deactivate_super+0xb1/0xd0 fs/super.c:363
 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f13ed08d537
RSP: 002b:00007ffc492f9bc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f13ed08d537
RDX: 00007ffc492f9c9b RSI: 000000000000000a RDI: 00007ffc492f9c90
RBP: 00007ffc492f9c90 R08: 00000000ffffffff R09: 00007ffc492f9a60
R10: 0000555556a3c8b3 R11: 0000000000000246 R12: 00007f13ed0e6b24
R13: 00007ffc492fad50 R14: 0000555556a3c810 R15: 00007ffc492fad90
 </TASK>
INFO: task syz-executor.2:5099 blocked for more than 144 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.2  state:D stack:24024 pid:5099  ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_iop_permission+0xbc/0x120 fs/kernfs/inode.c:288
 do_inode_permission fs/namei.c:458 [inline]
 inode_permission.part.0+0x3d6/0x670 fs/namei.c:525
 inode_permission fs/namei.c:506 [inline]
 may_lookup fs/namei.c:1715 [inline]
 link_path_walk.part.0+0x81e/0xdf0 fs/namei.c:2262
 link_path_walk fs/namei.c:2245 [inline]
 path_openat+0x25c/0x2a50 fs/namei.c:3710
 do_filp_open+0x1ba/0x410 fs/namei.c:3741
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __x64_sys_openat+0x143/0x1f0 fs/open.c:1337
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fec5948bc38
RSP: 002b:00007ffdf7e4f910 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000000009a3 RCX: 00007fec5948bc38
RDX: 0000000000090800 RSI: 00007fec594e6bc8 RDI: 00000000ffffff9c
RBP: 00007ffdf7e4f9dc R08: 0000000000090800 R09: 00007fec594e6bc8
R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000000
R13: 000000000013239e R14: 0000000000000009 R15: 00007ffdf7e4fa40
 </TASK>
INFO: task syz-executor.3:5103 blocked for more than 145 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.3  state:D stack:23904 pid:5103  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_find_and_get_ns+0x73/0xc0 fs/kernfs/dir.c:891
 kernfs_find_and_get include/linux/kernfs.h:597 [inline]
 sysfs_unmerge_group+0x61/0x170 fs/sysfs/group.c:365
 dpm_sysfs_remove+0x66/0xb0 drivers/base/power/sysfs.c:833
 device_del+0x20f/0xc80 drivers/base/core.c:3643
 device_unregister+0x1e/0xc0 drivers/base/core.c:3698
 bdi_unregister+0x42d/0x600 mm/backing-dev.c:1072
 generic_shutdown_super+0x33d/0x410 fs/super.c:507
 kill_anon_super+0x3a/0x60 fs/super.c:1086
 fuse_kill_sb_anon+0x1e3/0x330 fs/fuse/inode.c:1813
 deactivate_locked_super+0x98/0x160 fs/super.c:332
 deactivate_super+0xb1/0xd0 fs/super.c:363
 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1291
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x23c/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f383f88d537
RSP: 002b:00007ffc374be4e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f383f88d537
RDX: 00007ffc374be5bb RSI: 000000000000000a RDI: 00007ffc374be5b0
RBP: 00007ffc374be5b0 R08: 00000000ffffffff R09: 00007ffc374be380
R10: 00005555566198b3 R11: 0000000000000246 R12: 00007f383f8e6b24
R13: 00007ffc374bf670 R14: 0000555556619810 R15: 00007ffc374bf6b0
 </TASK>
INFO: task syz-executor.4:5104 blocked for more than 145 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4  state:D stack:24424 pid:5104  ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_iop_permission+0xbc/0x120 fs/kernfs/inode.c:288
 do_inode_permission fs/namei.c:458 [inline]
 inode_permission.part.0+0x3d6/0x670 fs/namei.c:525
 inode_permission fs/namei.c:506 [inline]
 may_lookup fs/namei.c:1715 [inline]
 link_path_walk.part.0+0x81e/0xdf0 fs/namei.c:2262
 link_path_walk fs/namei.c:2245 [inline]
 path_openat+0x25c/0x2a50 fs/namei.c:3710
 do_filp_open+0x1ba/0x410 fs/namei.c:3741
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __x64_sys_openat+0x143/0x1f0 fs/open.c:1337
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa83e08bc38
RSP: 002b:00007ffc648284f0 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000a53 RCX: 00007fa83e08bc38
RDX: 0000000000090800 RSI: 00007fa83e0e6bc8 RDI: 00000000ffffff9c
RBP: 00007ffc648285bc R08: 0000000000090800 R09: 00007fa83e0e6bc8
R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000000
R13: 00000000001322b0 R14: 0000000000000009 R15: 00007ffc64828620
 </TASK>
INFO: task syz-executor.5:5105 blocked for more than 146 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.5  state:D stack:24080 pid:5105  ppid:1      flags:0x00000004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_iop_permission+0xbc/0x120 fs/kernfs/inode.c:288
 do_inode_permission fs/namei.c:458 [inline]
 inode_permission.part.0+0x3d6/0x670 fs/namei.c:525
 inode_permission fs/namei.c:506 [inline]
 may_lookup fs/namei.c:1715 [inline]
 link_path_walk.part.0+0x81e/0xdf0 fs/namei.c:2262
 link_path_walk fs/namei.c:2245 [inline]
 path_openat+0x25c/0x2a50 fs/namei.c:3710
 do_filp_open+0x1ba/0x410 fs/namei.c:3741
 do_sys_openat2+0x16d/0x4c0 fs/open.c:1310
 do_sys_open fs/open.c:1326 [inline]
 __do_sys_openat fs/open.c:1342 [inline]
 __se_sys_openat fs/open.c:1337 [inline]
 __x64_sys_openat+0x143/0x1f0 fs/open.c:1337
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fce6968bc38
RSP: 002b:00007fff6fd249b0 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000974 RCX: 00007fce6968bc38
RDX: 0000000000090800 RSI: 00007fce696e6bc8 RDI: 00000000ffffff9c
RBP: 00007fff6fd24a7c R08: 0000000000090800 R09: 00007fce696e6bc8
R10: 0000000000000000 R11: 0000000000000287 R12: 0000000000000000
R13: 00000000001325d9 R14: 000000000000001c R15: 00007fff6fd24ae0
 </TASK>
INFO: task udevadm:22843 blocked for more than 146 seconds.
      Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevadm         state:D stack:26696 pid:22843 ppid:22429  flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5293 [inline]
 __schedule+0xb8a/0x5450 kernel/sched/core.c:6606
 schedule+0xde/0x1b0 kernel/sched/core.c:6682
 rwsem_down_read_slowpath+0x5a7/0xb20 kernel/locking/rwsem.c:1095
 __down_read_common kernel/locking/rwsem.c:1260 [inline]
 __down_read kernel/locking/rwsem.c:1269 [inline]
 down_read+0xe6/0x450 kernel/locking/rwsem.c:1511
 kernfs_dop_revalidate+0xf0/0x5b0 fs/kernfs/dir.c:1130
 d_revalidate fs/namei.c:856 [inline]
 d_revalidate fs/namei.c:853 [inline]
 lookup_fast+0x22d/0x520 fs/namei.c:1646
 walk_component+0x5e/0x5a0 fs/namei.c:1989
 link_path_walk.part.0+0x730/0xdf0 fs/namei.c:2320
 link_path_walk fs/namei.c:2244 [inline]
 path_lookupat+0xb7/0x840 fs/namei.c:2473
 filename_lookup+0x1d2/0x590 fs/namei.c:2503
 user_path_at_empty+0x46/0x60 fs/namei.c:2876
 do_readlinkat+0xcd/0x2f0 fs/stat.c:471
 __do_sys_readlink fs/stat.c:504 [inline]
 __se_sys_readlink fs/stat.c:501 [inline]
 __x64_sys_readlink+0x78/0xb0 fs/stat.c:501
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fc7e8327277
RSP: 002b:00007ffda00dcb58 EFLAGS: 00000206 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 000056491c80c770 RCX: 00007fc7e8327277
RDX: 0000000000000400 RSI: 00007ffda00dcf68 RDI: 00007ffda00dcb68
RBP: 00007ffda00dd3a8 R08: 000056491bba1837 R09: 0000000000000000
R10: 000056491c80b3d0 R11: 0000000000000206 R12: 0000000000000200
R13: 00007ffda00dcf68 R14: 00007ffda00dcb68 R15: 000056491c7fada0
 </TASK>

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
 #0: ffffffff8c790fb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507
1 lock held by rcu_tasks_trace/13:
 #0: ffffffff8c790cb0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x26/0xc70 kernel/rcu/tasks.h:507
1 lock held by khungtaskd/28:
 #0: ffffffff8c791b00 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x57/0x264 kernel/locking/lockdep.c:6494
1 lock held by udevd/4428:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0xf0/0x5b0 fs/kernfs/dir.c:1130
2 locks held by getty/4744:
 #0: ffff88802b9f3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:244
 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2177
1 lock held by syz-executor.1/5091:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_find_and_get_ns+0x73/0xc0 fs/kernfs/dir.c:891
1 lock held by syz-executor.0/5093:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_find_and_get_ns+0x73/0xc0 fs/kernfs/dir.c:891
1 lock held by syz-executor.2/5099:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_iop_permission+0xbc/0x120 fs/kernfs/inode.c:288
1 lock held by syz-executor.3/5103:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_find_and_get_ns+0x73/0xc0 fs/kernfs/dir.c:891
1 lock held by syz-executor.4/5104:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_iop_permission+0xbc/0x120 fs/kernfs/inode.c:288
1 lock held by syz-executor.5/5105:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_iop_permission+0xbc/0x120 fs/kernfs/inode.c:288
2 locks held by kworker/u4:8/5220:
 #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline]
 #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline]
 #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:636 [inline]
 #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:663 [inline]
 #0: ffff888012479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x86d/0x1710 kernel/workqueue.c:2260
 #1: ffffc90004c6fda8 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x8a1/0x1710 kernel/workqueue.c:2264
2 locks held by syz-executor.4/22842:
 #0: ffff888034c6e0e0 (&type->s_umount_key#27/1){+.+.}-{3:3}, at: alloc_super+0x22e/0xb60 fs/super.c:228
 #1: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_add_one+0xa7/0x4f0 fs/kernfs/dir.c:754
1 lock held by udevadm/22843:
 #0: ffff888012473948 (&root->kernfs_rwsem){++++}-{3:3}, at: kernfs_dop_revalidate+0xf0/0x5b0 fs/kernfs/dir.c:1130
2 locks held by syz-executor.2/22851:

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

NMI backtrace for cpu 0
CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x24/0x18a lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x333/0x3c0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
 watchdog+0xc75/0xfc0 kernel/hung_task.c:377
 kthread+0x2e8/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 22842 Comm: syz-executor.4 Not tainted 6.2.0-rc5-syzkaller-00221-gab072681eabe #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
RIP: 0010:match_held_lock+0x1/0xc0 kernel/locking/lockdep.c:5113
Code: b9 ff 48 c7 c7 40 4e 4c 8a e8 3c fe b9 ff e8 ba 78 ff ff 31 c0 48 83 c4 08 5d c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 53 <48> 89 fb 48 83 ec 08 48 39 77 10 74 6a 66 f7 47 22 f0 ff 74 5a 48
RSP: 0018:ffffc90015337538 EFLAGS: 00000093
RAX: 0000000000000005 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffff888012473908 RDI: ffff8880781627a0
RBP: ffff888012473908 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52002a66ea3 R11: 0000000000000000 R12: ffff888078161d40
R13: ffff888078162778 R14: 00000000ffffffff R15: ffff8880781627a0
FS:  00007fa83eeab700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fec4fc3e000 CR3: 000000001d460000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 __lock_is_held kernel/locking/lockdep.c:5409 [inline]
 lock_is_held_type+0xab/0x140 kernel/locking/lockdep.c:5711
 lock_is_held include/linux/lockdep.h:283 [inline]
 rwsem_try_write_lock kernel/locking/rwsem.c:613 [inline]
 rwsem_down_write_slowpath+0xc69/0x12e0 kernel/locking/rwsem.c:1161
 __down_write_common kernel/locking/rwsem.c:1305 [inline]
 __down_write_common kernel/locking/rwsem.c:1302 [inline]
 __down_write kernel/locking/rwsem.c:1314 [inline]
 down_write+0x1e8/0x220 kernel/locking/rwsem.c:1563
 kernfs_add_one+0xa7/0x4f0 fs/kernfs/dir.c:754
 __kernfs_create_file+0x2a0/0x350 fs/kernfs/file.c:1076
 sysfs_add_file_mode_ns+0x213/0x3f0 fs/sysfs/file.c:294
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x322/0xb10 fs/sysfs/group.c:148
 internal_create_groups.part.0+0x90/0x140 fs/sysfs/group.c:188
 internal_create_groups fs/sysfs/group.c:184 [inline]
 sysfs_create_groups+0x29/0x50 fs/sysfs/group.c:214
 create_dir lib/kobject.c:68 [inline]
 kobject_add_internal+0x318/0x8f0 lib/kobject.c:223
 kobject_add_varg lib/kobject.c:358 [inline]
 kobject_init_and_add+0x105/0x160 lib/kobject.c:441
 ext4_register_sysfs+0xb9/0x360 fs/ext4/sysfs.c:526
 __ext4_fill_super fs/ext4/super.c:5491 [inline]
 ext4_fill_super+0x9ce0/0xb220 fs/ext4/super.c:5644
 get_tree_bdev+0x444/0x760 fs/super.c:1282
 vfs_get_tree+0x8d/0x2f0 fs/super.c:1489
 do_new_mount fs/namespace.c:3145 [inline]
 path_mount+0x132a/0x1e20 fs/namespace.c:3475
 do_mount fs/namespace.c:3488 [inline]
 __do_sys_mount fs/namespace.c:3697 [inline]
 __se_sys_mount fs/namespace.c:3674 [inline]
 __x64_sys_mount+0x283/0x300 fs/namespace.c:3674
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa83e08d5fa
Code: 48 c7 c2 b8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb d2 e8 b8 04 00 00 0f 1f 84 00 00 00 00 00 49 89 ca b8 a5 00 00 00 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:00007fa83eeaaf88 EFLAGS: 00000202 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00000000000004a6 RCX: 00007fa83e08d5fa
RDX: 00000000200004c0 RSI: 0000000020000280 RDI: 00007fa83eeaafe0
RBP: 00007fa83eeab020 R08: 00007fa83eeab020 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000200004c0
R13: 0000000020000280 R14: 00007fa83eeaafe0 R15: 0000000020000240
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/01/29 22:52 upstream ab072681eabe 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in kernfs_dop_revalidate
2023/01/26 05:12 upstream 7c46948a6e9c 9dfcf09c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in kernfs_dop_revalidate
2022/12/07 08:09 linux-next 591cd61541b9 d88f3abb .config console log report info ci-upstream-linux-next-kasan-gce-root INFO: task hung in kernfs_dop_revalidate
* Struck through repros no longer work on HEAD.