syzbot


INFO: task hung in __sb_start_write (2)

Status: closed as invalid on 2018/09/17 14:02
Reported-by: syzbot+a434aff66156fa42c41d@syzkaller.appspotmail.com
First crash: 1479d, last: 1476d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in __sb_start_write 1508 1536d 1606d 0/24 closed as invalid on 2018/07/13 10:38

Sample crash report:
INFO: task rs:main Q:Reg:5210 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
rs:main Q:Reg   D15768  5210      1 0x00000000
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 file_start_write include/linux/fs.h:2758 [inline]
 vfs_write+0x42a/0x560 fs/read_write.c:548
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f4351d5b19d
Code: Bad RIP value.
RSP: 002b:00007f43502fc000 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000000000f5 RCX: 00007f4351d5b19d
RDX: 00000000000000f5 RSI: 0000000001563a90 RDI: 0000000000000005
RBP: 0000000001563a90 R08: 0000000001563af9 R09: 00007f43516d8347
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f43502fc480 R14: 0000000000000002 R15: 0000000001563890
INFO: task syz-executor0:5352 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D17328  5352      1 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 sb_start_write include/linux/fs.h:1566 [inline]
 mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 do_unlinkat+0x2b7/0xa30 fs/namei.c:4045
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4108
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456de7
Code: Bad RIP value.
RSP: 002b:00007fffed4df7e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000456de7
RDX: 00007fffed4df800 RSI: 00007fffed4df890 RDI: 00007fffed4df890
RBP: 0000000000001453 R08: 0000000000000000 R09: 0000000000000011
R10: 000000000000000a R11: 0000000000000206 R12: 00007fffed4e08f0
R13: 000000000235c940 R14: 0000000000000000 R15: badc0ffeebadface
INFO: task syz-executor4:5354 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor4   D17152  5354      1 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 sb_start_write include/linux/fs.h:1566 [inline]
 mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 do_rmdir+0x1a3/0x630 fs/namei.c:3925
 __do_sys_rmdir fs/namei.c:3959 [inline]
 __se_sys_rmdir fs/namei.c:3957 [inline]
 __x64_sys_rmdir+0x36/0x40 fs/namei.c:3957
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456e07
Code: Bad RIP value.
RSP: 002b:00007ffe2e1748f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 0000000000000065 RCX: 0000000000456e07
RDX: 0000000000000000 RSI: 00007ffe2e175a00 RDI: 00007ffe2e175a00
RBP: 00000000000015ce R08: 0000000000000000 R09: 0000000000000001
R10: 000000000000000a R11: 0000000000000202 R12: 00007ffe2e175a00
R13: 0000000001a3b940 R14: 0000000000000000 R15: badc0ffeebadface
INFO: task syz-executor6:5358 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D17328  5358      1 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 sb_start_write include/linux/fs.h:1566 [inline]
 mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 do_unlinkat+0x2b7/0xa30 fs/namei.c:4045
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4108
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456de7
Code: Bad RIP value.
RSP: 002b:00007fff871d8b48 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000456de7
RDX: 00007fff871d8b60 RSI: 00007fff871d8bf0 RDI: 00007fff871d8bf0
RBP: 000000000000159a R08: 0000000000000000 R09: 0000000000000011
R10: 000000000000000a R11: 0000000000000206 R12: 00007fff871d9c50
R13: 00000000025af940 R14: 0000000000000000 R15: badc0ffeebadface
INFO: task syz-executor1:5359 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor1   D16136  5359      1 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 sb_start_write include/linux/fs.h:1566 [inline]
 mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 do_unlinkat+0x2b7/0xa30 fs/namei.c:4045
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4108
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456de7
Code: Bad RIP value.
RSP: 002b:00007fffc3b247a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000456de7
RDX: 00007fffc3b247c0 RSI: 00007fffc3b24850 RDI: 00007fffc3b24850
RBP: 0000000000001d66 R08: 0000000000000000 R09: 0000000000000011
R10: 000000000000000a R11: 0000000000000202 R12: 00007fffc3b258b0
R13: 00000000020b2940 R14: 0000000000000000 R15: badc0ffeebadface
INFO: task syz-executor2:16373 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D18720 16373      1 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 sb_start_write include/linux/fs.h:1566 [inline]
 mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 do_unlinkat+0x2b7/0xa30 fs/namei.c:4045
 __do_sys_unlink fs/namei.c:4110 [inline]
 __se_sys_unlink fs/namei.c:4108 [inline]
 __x64_sys_unlink+0x42/0x50 fs/namei.c:4108
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x456de7
Code: Bad RIP value.
RSP: 002b:00007ffe6cf63de8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000456de7
RDX: 00007ffe6cf63e00 RSI: 00007ffe6cf63e90 RDI: 00007ffe6cf63e90
RBP: 00000000000009ca R08: 0000000000000000 R09: 0000000000000010
R10: 000000000000000a R11: 0000000000000206 R12: 00007ffe6cf64ef0
R13: 0000000001aa2940 R14: 0000000000000000 R15: badc0ffeebadface
INFO: task syz-executor5:11799 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D16864 11799   5356 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 file_start_write include/linux/fs.h:2758 [inline]
 vfs_write+0x42a/0x560 fs/read_write.c:548
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: Bad RIP value.
RSP: 002b:00007fc89cd61c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc89cd626d4 RCX: 0000000000457099
RDX: 00000000fffffe38 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d82c8 R14: 00000000004cada0 R15: 0000000000000000
INFO: task syz-executor5:11802 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D25400 11802   5356 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 sb_start_write include/linux/fs.h:1566 [inline]
 mnt_want_write_file+0x68/0x110 fs/namespace.c:418
 ext4_ioctl+0xca9/0x4210 fs/ext4/ioctl.c:849
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
 __do_sys_ioctl fs/ioctl.c:709 [inline]
 __se_sys_ioctl fs/ioctl.c:707 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: Bad RIP value.
RSP: 002b:00007fc89cd40c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc89cd416d4 RCX: 0000000000457099
RDX: 0000000004000001 RSI: 000000000000660c RDI: 0000000000000003
RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cfdc0 R14: 00000000004bec18 R15: 0000000000000001
INFO: task syz-executor5:11803 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D24904 11803   5356 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline]
 rwsem_down_read_failed+0x362/0x610 kernel/locking/rwsem-xadd.c:286
 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94
 __down_read arch/x86/include/asm/rwsem.h:83 [inline]
 __percpu_down_read+0x14c/0x1d0 kernel/locking/percpu-rwsem.c:85
 percpu_down_read_preempt_disable include/linux/percpu-rwsem.h:49 [inline]
 percpu_down_read include/linux/percpu-rwsem.h:59 [inline]
 __sb_start_write+0x340/0x370 fs/super.c:1387
 sb_start_write include/linux/fs.h:1566 [inline]
 mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 do_last fs/namei.c:3311 [inline]
 path_openat+0x4c9c/0x5160 fs/namei.c:3534
 do_filp_open+0x255/0x380 fs/namei.c:3564
 do_sys_open+0x568/0x700 fs/open.c:1063
 __do_sys_openat fs/open.c:1090 [inline]
 __se_sys_openat fs/open.c:1084 [inline]
 __x64_sys_openat+0x9d/0x100 fs/open.c:1084
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: Bad RIP value.
RSP: 002b:00007fc89cd1fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc89cd206d4 RCX: 0000000000457099
RDX: 0000000000002761 RSI: 0000000020000480 RDI: ffffffffffffffff
RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d3678 R14: 00000000004c83ea R15: 0000000000000002
INFO: task syz-executor5:11812 blocked for more than 140 seconds.
      Not tainted 4.19.0-rc2+ #230
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D26456 11812   5356 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2825 [inline]
 __schedule+0x86c/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3575
 __mutex_lock_common kernel/locking/mutex.c:1003 [inline]
 __mutex_lock+0xbfb/0x1710 kernel/locking/mutex.c:1073
 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
 __fdget_pos+0x1bb/0x200 fs/file.c:766
 fdget_pos include/linux/file.h:70 [inline]
 ksys_write+0x7f/0x260 fs/read_write.c:593
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: Bad RIP value.
RSP: 002b:00007fc89ccfec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc89ccff6d4 RCX: 0000000000457099
RDX: 00000000fffffe38 RSI: 0000000020000080 RDI: 0000000000000003
RBP: 0000000000930280 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d82c8 R14: 00000000004cada0 R15: 0000000000000003

Showing all locks held in the system:
1 lock held by khungtaskd/984:
 #0: 00000000134aa7cf (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4436
2 locks held by rs:main Q:Reg/5210:
 #0: 00000000450310ae (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
 #1: 00000000f31cca67 (sb_writers#5){++++}, at: file_start_write include/linux/fs.h:2758 [inline]
 #1: 00000000f31cca67 (sb_writers#5){++++}, at: vfs_write+0x42a/0x560 fs/read_write.c:548
1 lock held by rsyslogd/5212:
 #0: 00000000ed8aafd8 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
2 locks held by getty/5303:
 #0: 0000000024196eef (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 0000000032e52922 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5304:
 #0: 000000004d5393fb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000005bce4469 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5305:
 #0: 0000000037c69b65 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000002cc2bfd1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5306:
 #0: 00000000cf3a61bb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000ebe6b44e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5307:
 #0: 000000001769c1bd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000008da801b6 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5308:
 #0: 00000000fc646819 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000a0240112 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5309:
 #0: 00000000fdd828b1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000002b147d1a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
1 lock held by syz-executor0/5352:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
1 lock held by syz-executor4/5354:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
1 lock held by syz-executor6/5358:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
1 lock held by syz-executor1/5359:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
1 lock held by syz-executor4/11655:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: file_start_write include/linux/fs.h:2758 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: do_sendfile+0xac0/0xe20 fs/read_write.c:1439
1 lock held by syz-executor2/16373:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
1 lock held by syz-executor0/23382:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: file_start_write include/linux/fs.h:2758 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: do_sendfile+0xac0/0xe20 fs/read_write.c:1439
2 locks held by syz-executor0/23464:
5 locks held by syz-executor0/23541:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: file_start_write include/linux/fs.h:2758 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: do_sendfile+0xac0/0xe20 fs/read_write.c:1439
 #1: 000000008a0787c4 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1821 [inline]
 #1: 000000008a0787c4 (&rq->lock){-.-.}, at: __schedule+0x236/0x1ed0 kernel/sched/core.c:3411
 #2: 00000000134aa7cf (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:413 [inline]
 #2: 00000000134aa7cf (rcu_read_lock){....}, at: update_curr+0x383/0xbe0 kernel/sched/fair.c:829
 #3: 000000006f8c307d (&(&virtscsi_vq->vq_lock)->rlock){-.-.}, at: virtscsi_kick_cmd+0x2f/0x130 drivers/scsi/virtio_scsi.c:473
 #4: 000000008a0787c4 (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1821 [inline]
 #4: 000000008a0787c4 (&rq->lock){-.-.}, at: __schedule+0x236/0x1ed0 kernel/sched/core.c:3411
2 locks held by syz-executor5/11799:
 #0: 000000006e2464ff (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
 #1: 00000000f31cca67 (sb_writers#5){++++}, at: file_start_write include/linux/fs.h:2758 [inline]
 #1: 00000000f31cca67 (sb_writers#5){++++}, at: vfs_write+0x42a/0x560 fs/read_write.c:548
1 lock held by syz-executor5/11802:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write_file+0x68/0x110 fs/namespace.c:418
1 lock held by syz-executor5/11803:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
1 lock held by syz-executor5/11812:
 #0: 000000006e2464ff (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
1 lock held by syz-executor5/11813:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write_file+0x68/0x110 fs/namespace.c:418
1 lock held by syz-executor3/11782:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
1 lock held by syz-executor3/11801:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
2 locks held by syz-executor7/11789:
 #0: 00000000b247195c (&bdev->bd_fsfreeze_mutex){+.+.}, at: freeze_bdev+0x2d/0x250 fs/block_dev.c:496
 #1: 00000000f31cca67 (sb_writers#5){++++}, at: percpu_down_write+0xaf/0x540 kernel/locking/percpu-rwsem.c:145
1 lock held by syz-executor7/11805:
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: sb_start_write include/linux/fs.h:1566 [inline]
 #0: 00000000f31cca67 (sb_writers#5){++++}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360

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

NMI backtrace for cpu 1
CPU: 1 PID: 984 Comm: khungtaskd Not tainted 4.19.0-rc2+ #230
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+0x1c4/0x2b4 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.3+0x63/0xa2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_all_cpu_backtrace include/linux/nmi.h:144 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
 watchdog+0xb3e/0x1050 kernel/hung_task.c:265
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2018/09/10 04:20 upstream 9a5682765a2e 6b5120a4 .config log report
ci-upstream-kasan-gce-selinux-root 2018/09/07 09:58 upstream ca16eb342ebe e30d3b52 .config log report
ci-upstream-linux-next-kasan-gce-root 2018/09/07 21:55 linux-next f2b6e66e9885 69cfeb80 .config log report
* Struck through repros no longer work on HEAD.