syzbot


INFO: task hung in __blkdev_get (5)

Status: auto-closed as invalid on 2021/03/11 14:46
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 870d, last: 656d
similar bugs (9):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in __blkdev_get C 1504 1033d 1265d 0/3 public: reported C repro on 2019/04/12 00:00
android-44 INFO: task hung in __blkdev_get syz 521 1035d 1263d 0/2 public: reported syz repro on 2019/04/14 00:02
android-414 INFO: task hung in __blkdev_get 1859 1032d 1264d 0/1 auto-closed as invalid on 2020/02/28 16:13
upstream INFO: task hung in __blkdev_get (3) 1 1258d 1258d 0/24 closed as invalid on 2019/05/08 13:05
upstream INFO: task hung in __blkdev_get (2) 11 1357d 1481d 0/24 closed as dup on 2018/09/08 15:48
linux-4.14 INFO: task hung in __blkdev_get C 730 9h15m 1266d 0/1 upstream: reported C repro on 2019/04/11 13:17
upstream INFO: task hung in __blkdev_get C 662 1628d 1754d 6/24 fixed on 2018/05/08 18:30
linux-4.19 INFO: task hung in __blkdev_get C error 117 7d03h 1142d 0/1 upstream: reported C repro on 2019/08/13 00:10
upstream INFO: task hung in __blkdev_get (4) 1 1077d 1077d 0/24 auto-closed as invalid on 2020/01/15 05:33

Sample crash report:
INFO: task systemd-udevd:4895 blocked for more than 143 seconds.
      Not tainted 5.10.0-rc7-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:systemd-udevd   state:D stack:23208 pid: 4895 ppid:     1 flags:0x00004100
Call Trace:
 context_switch kernel/sched/core.c:3779 [inline]
 __schedule+0x893/0x2130 kernel/sched/core.c:4528
 schedule+0xcf/0x270 kernel/sched/core.c:4606
 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:4665
 __mutex_lock_common kernel/locking/mutex.c:1033 [inline]
 __mutex_lock+0x3e2/0x10e0 kernel/locking/mutex.c:1103
 __blkdev_get+0x457/0x1870 fs/block_dev.c:1479
 blkdev_get+0xd1/0x240 fs/block_dev.c:1634
 blkdev_open+0x21d/0x2b0 fs/block_dev.c:1751
 do_dentry_open+0x4b9/0x11b0 fs/open.c:817
 do_open fs/namei.c:3252 [inline]
 path_openat+0x1b9a/0x2730 fs/namei.c:3369
 do_filp_open+0x17e/0x3c0 fs/namei.c:3396
 do_sys_openat2+0x16d/0x420 fs/open.c:1168
 do_sys_open fs/open.c:1184 [inline]
 __do_sys_open fs/open.c:1192 [inline]
 __se_sys_open fs/open.c:1188 [inline]
 __x64_sys_open+0x119/0x1c0 fs/open.c:1188
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd822c04840
RSP: 002b:00007ffe33081818 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007ffe33081910 RCX: 00007fd822c04840
RDX: 0000556734698fe3 RSI: 00000000000a0800 RDI: 0000556734c97ad0
RBP: 00007ffe33081e00 R08: 0000556734698670 R09: 0000000000000010
R10: 000055673541dd40 R11: 0000000000000246 R12: 00007ffe330819c0
R13: 0000556734be3010 R14: 0000556735127f00 R15: 00007ffe33081890

Showing all locks held in the system:
1 lock held by khungtaskd/1656:
 #0: ffffffff8b3378e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6254
1 lock held by systemd-udevd/4895:
 #0: ffff888148012100 (&bdev->bd_mutex){+.+.}-{3:3}, at: __blkdev_get+0x457/0x1870 fs/block_dev.c:1479
1 lock held by in:imklog/8162:
 #0: ffff88801abf14f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932
2 locks held by syz-executor.3/32016:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1656 Comm: khungtaskd Not tainted 5.10.0-rc7-syzkaller #0
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+0x107/0x163 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:209 [inline]
 watchdog+0xd43/0xfa0 kernel/hung_task.c:294
 kthread+0x3b1/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4884 Comm: systemd-journal Not tainted 5.10.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:desc_read_finalized_seq+0x15b/0x1c0 kernel/printk/printk_ringbuffer.c:1779
Code: fc ff df 49 c7 04 04 00 00 00 00 48 8b 44 24 58 65 48 2b 04 25 28 00 00 00 75 63 48 83 c4 60 44 89 e8 5b 5d 41 5c 41 5d 41 5e <41> 5f c3 e8 6d 32 17 00 48 8d 7d 10 48 b8 00 00 00 00 00 fc ff df
RSP: 0018:ffffc9000167fb78 EFLAGS: 00000086
RAX: 00000000fffffffe RBX: ffffc9000167fc50 RCX: ffffffff8158d187
RDX: ffff88802553cec0 RSI: ffffffff8158d1ca RDI: 0000000000000005
RBP: ffffffff8b312ab8 R08: 0000000000000001 R09: ffffc9000167fc57
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000001159
R13: ffffffff8b248a40 R14: 0000000000003159 R15: dffffc0000000000
FS:  00007f6b54d6c8c0(0000) GS:ffff8880b9f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6b50fefb78 CR3: 00000000204da000 CR4: 0000000000350ee0
Call Trace:
 prb_read kernel/printk/printk_ringbuffer.c:1802 [inline]
 _prb_read_valid+0x1a1/0x6d0 kernel/printk/printk_ringbuffer.c:1882
 prb_first_valid_seq+0x78/0xd0 kernel/printk/printk_ringbuffer.c:1987
 devkmsg_read+0x274/0x740 kernel/printk/printk.c:785
 vfs_read+0x1b5/0x570 fs/read_write.c:494
 ksys_read+0x12d/0x250 fs/read_write.c:634
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7f6b542fc210
Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24
RSP: 002b:00007ffd5820e6c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00007ffd58211140 RCX: 00007f6b542fc210
RDX: 0000000000002000 RSI: 00007ffd5820ef40 RDI: 0000000000000009
RBP: 0000000000000000 R08: 0000000000000008 R09: 00007ffd582d90f0
R10: 00000000000973e4 R11: 0000000000000246 R12: 00007ffd5820ef40
R13: 00007ffd58211098 R14: 000055b44cfbf958 R15: 0005b6314e1794e7

Crashes (8):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2020/12/11 14:42 upstream 33dc9614dc20 ba24ffcd .config log report info
ci-upstream-kasan-gce-selinux-root 2020/10/30 12:05 upstream 07e088730245 a6e3ac3b .config log report info
ci-upstream-kasan-gce-root 2020/08/30 22:29 upstream 1127b219ce94 d5a3ae1f .config log report
ci-upstream-kasan-gce-root 2020/06/24 14:22 upstream 7ae77150d94d 54566aff .config log report
ci-upstream-kasan-gce-selinux-root 2020/05/11 03:16 upstream e99332e7b4cd 8742a2b9 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/05/26 11:20 linux-next b0523c7b1c9d 8ca3b7d2 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/05/25 14:32 linux-next 7b4cb0a48db0 30927cd7 .config log report
ci-upstream-linux-next-kasan-gce-root 2020/05/19 14:52 linux-next ac935d227366 6d882fd2 .config log report
* Struck through repros no longer work on HEAD.