syzbot


INFO: task hung (2)

Status: public: reported C repro on 2019/04/12 00:00
Reported-by: syzbot+e8d7c6bf8d014e27fc10@syzkaller.appspotmail.com
First crash: 2492d, last: 2330d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung C 13878 2438d 2503d 3/26 fixed on 2017/09/26 01:38
android-49 INFO: task hung 5242 2492d 2497d 0/3 closed as invalid on 2017/08/02 08:40
upstream INFO: task hung (2) fs 13786 2372d 2438d 0/26 closed as invalid on 2017/12/04 13:21

Sample crash report:
IPv6: Can't replace route, no match found
IPv6: Can't replace route, no match found
IPv6: Can't replace route, no match found
IPv6: Can't replace route, no match found
IPv6: Can't replace route, no match found
INFO: task init:12200 blocked for more than 120 seconds.
      Not tainted 4.9.76-g9154940 #20
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
init            D27568 12200      1 0x00000000
 ffff8801d8590000 ffff8801d7e8cfc0 ffff8801d84e8540 ffff8801d80ab000
 ffff8801db321b98 ffff8801c5aef7c8 ffffffff8389f9fb 0000000000000000
 0000000000000007
IPv6: Can't replace route, no match found
 00ff8801d8590000 ffff8801db322468 ffff8801db322490
 [<ffffffff838a0f9f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3550
 [<ffffffff838a1923>] schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3583
 [<ffffffff838a6f32>] __mutex_lock_common kernel/locking/mutex.c:582 [inline]
 [<ffffffff838a6f32>] mutex_lock_nested+0x312/0x870 kernel/locking/mutex.c:621
 [<ffffffff82001707>] tty_open_by_driver drivers/tty/tty_io.c:2030 [inline]
 [<ffffffff82001707>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2108
 [<ffffffff8157a9fb>] chrdev_open+0x22b/0x4c0 fs/char_dev.c:392
 [<ffffffff81565aa7>] do_dentry_open+0x607/0xc60 fs/open.c:766
 [<ffffffff81569555>] vfs_open+0x105/0x220 fs/open.c:879
 [<ffffffff8159fcdc>] do_last fs/namei.c:3408 [inline]
 [<ffffffff8159fcdc>] path_openat+0x5ac/0x2910 fs/namei.c:3531
 [<ffffffff815a5837>] do_filp_open+0x197/0x290 fs/namei.c:3566
 [<ffffffff8156a032>] do_sys_open+0x352/0x4c0 fs/open.c:1072
 [<ffffffff8156a1cd>] SYSC_open fs/open.c:1090 [inline]
 [<ffffffff8156a1cd>] SyS_open+0x2d/0x40 fs/open.c:1085
 [<ffffffff838b0aa8>] entry_SYSCALL_64_fastpath+0x23/0xe2

Showing all locks held in the system:
2 locks held by khungtaskd/514:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81371d35>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81371d35>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81236eb0>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
1 lock held by rsyslogd/3200:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815d21af>] __fdget_pos+0x9f/0xc0 fs/file.c:781
2 locks held by getty/3328:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838aec72>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff82008494>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by init/12200:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open_by_driver drivers/tty/tty_io.c:2030 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2108
1 lock held by init/12201:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open_by_driver drivers/tty/tty_io.c:2030 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2108
1 lock held by init/12202:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open_by_driver drivers/tty/tty_io.c:2030 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2108
1 lock held by init/12204:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open_by_driver drivers/tty/tty_io.c:2030 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2108
1 lock held by init/12205:
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open_by_driver drivers/tty/tty_io.c:2030 [inline]
 #0:  (tty_mutex){+.+.+.}, at: [<ffffffff82001707>] tty_open+0x407/0xdf0 drivers/tty/tty_io.c:2108

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

NMI backtrace for cpu 0
CPU: 0 PID: 514 Comm: khungtaskd Not tainted 4.9.76-g9154940 #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d926fd00 ffffffff81d93149 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810ba750 ffff8801d926fd38
 ffffffff81d9e26d 0000000000000000 0000000000000000 ffff8801d8590418
Call Trace:
 [<ffffffff81d93149>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d93149>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81d9e26d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81d9e3a7>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810ba844>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81372300>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81372300>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81372300>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81372300>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff811996ad>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b0db6>] ret_from_fork+0x46/0x60 arch/x86/entry/entry_64.S:460
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 28011 Comm: syzkaller512129 Not tainted 4.9.76-g9154940 #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801c65db000 task.stack: ffff8801c1fc8000
RIP: 0010:[<ffffffff81dc0399>] c [<ffffffff81dc0399>] clear_page_c_e+0x9/0x10 arch/x86/lib/clear_page_64.S:54
RSP: 0018:ffff8801c1fcfc20  EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00000000071e8000 RCX: 0000000000000000
RDX: 1ffff10038cbb83d RSI: ffffffff844de0e0 RDI: ffff8801c7997000
RBP: ffff8801c1fcfc68 R08: 0000000000000000 R09: 0000000000025960
R10: ffffffffffffffe8 R11: 0000000000000000 R12: dffffc0000000000
R13: 00000000071e6580 R14: ffff880000000000 R15: ffff8801c65db000
FS:  0000000000000000(0000) GS:ffff8801db300000(0063) knlGS:00000000089ea840
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000ffe854cc CR3: 00000001caa50000 CR4: 0000000000160670
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff814d4979c ffffffff8124746dc ffffea0007613bc0c ffffea0007613bc0c
 ffff8801c1fcfdc0c ffffea00071e0000c ffff8801c65673e0c ffffea00071e0020c
 ffff8801c0d72a00c ffff8801c1fcfcd8c ffffffff81547ef2c ffff8801c65db8b0c
Call Trace:
 [<ffffffff81547ef2>] __do_huge_pmd_anonymous_page mm/huge_memory.c:558 [inline]
 [<ffffffff81547ef2>] do_huge_pmd_anonymous_page+0x6c2/0x10d0 mm/huge_memory.c:700
 [<ffffffff814cee1b>] create_huge_pmd mm/memory.c:3403 [inline]
 [<ffffffff814cee1b>] __handle_mm_fault mm/memory.c:3553 [inline]
 [<ffffffff814cee1b>] handle_mm_fault+0x158b/0x2530 mm/memory.c:3614
 [<ffffffff810dd632>] __do_page_fault+0x5c2/0xd40 arch/x86/mm/fault.c:1406
 [<ffffffff810dddd7>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1469
 [<ffffffff838b1dc8>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1038
Code: c89 c47 c18 c48 c89 c47 c20 c48 c89 c47 c28 c48 c89 c47 c30 c48 c89 c47 c38 c48 c8d c7f c40 c75 cd9 c90 cc3 c0f c1f c80 c00 c00 c00 c00 cb9 c00 c10 c00 c00 c31 cc0 cf3 caa c<c3> c90 c90 c90 c90 c90 c90 c55 c48 c89 ce5 c41 c57 c41 c56 c41 c55 c41 c54 c49 c89 c

Crashes (52750):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/01/11 21:50 https://android.googlesource.com/kernel/common android-4.9 91549408ceb8 9dc808a6 .config console log report syz C ci-android-49-kasan-gce-386
2017/08/13 16:20 https://android.googlesource.com/kernel/common android-4.9 02f29ab1b950 6a0246bf .config console log report syz C ci-android-49-kasan-gce
2017/08/11 11:14 https://android.googlesource.com/kernel/common android-4.9 72a8dae2c25d 125de3e4 .config console log report syz C ci-android-49-kasan-gce
2017/11/09 13:00 https://android.googlesource.com/kernel/common android-4.9 a93e3124db19 e0a2b195 .config console log report syz ci-android-49-kasan-gce
2017/09/01 11:27 https://android.googlesource.com/kernel/common android-4.9 9100442602d8 a54dce00 .config console log report syz ci-android-49-kasan-gce
2017/11/22 14:46 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 14:44 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 14:38 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 14:28 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:57 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:51 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:51 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:45 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:42 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:38 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:37 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:32 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:25 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:17 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 13:14 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 12:56 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 12:29 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 12:17 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 12:14 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/22 12:13 https://android.googlesource.com/kernel/common android-4.9 fbb7468cbc28 cb27b030 .config console log report ci-android-49-kasan-gce
2017/11/20 12:15 https://android.googlesource.com/kernel/common android-4.9 44a3afcce10a eff27f33 .config console log report ci-android-49-kasan-gce
2017/11/15 21:51 https://android.googlesource.com/kernel/common android-4.9 a6d71ba67910 4121c7b5 .config console log report ci-android-49-kasan-gce
2017/11/01 00:18 https://android.googlesource.com/kernel/common android-4.9 1f46caef2914 e511d9f8 .config console log report ci-android-49-kasan-gce
2017/10/28 02:06 https://android.googlesource.com/kernel/common android-4.9 3861f0b0f12a 80c74880 .config console log report ci-android-49-kasan-gce
2017/10/22 05:06 https://android.googlesource.com/kernel/common android-4.9 9eaaf14c7829 ab829b1b .config console log report ci-android-49-kasan-gce
2017/10/22 00:20 https://android.googlesource.com/kernel/common android-4.9 9eaaf14c7829 ab829b1b .config console log report ci-android-49-kasan-gce
2017/10/09 13:25 https://android.googlesource.com/kernel/common android-4.9 e5eba30388a2 c26ea367 .config console log report ci-android-49-kasan-gce
2017/09/23 03:11 https://android.googlesource.com/kernel/common android-4.9 60cc09a9e3fc c26ea367 .config console log report ci-android-49-kasan-gce
2017/09/21 16:46 https://android.googlesource.com/kernel/common android-4.9 70b8b076f7bb 653022e6 .config console log report ci-android-49-kasan-gce
2017/09/16 06:41 https://android.googlesource.com/kernel/common android-4.9 f7d2974f3432 2bab8ad8 .config console log report ci-android-49-kasan-gce
2017/09/12 13:50 https://android.googlesource.com/kernel/common android-4.9 5316da5fec0d 0bd6a0a5 .config console log report ci-android-49-kasan-gce
2017/09/08 20:05 https://android.googlesource.com/kernel/common android-4.9 9983305173b5 d18bfda0 .config console log report ci-android-49-kasan-gce
2017/09/08 14:27 https://android.googlesource.com/kernel/common android-4.9 9983305173b5 d18bfda0 .config console log report ci-android-49-kasan-gce
2017/09/06 18:17 https://android.googlesource.com/kernel/common android-4.9 6ec105282807 0ed1da4a .config console log report ci-android-49-kasan-gce
2017/09/02 19:26 https://android.googlesource.com/kernel/common android-4.9 9100442602d8 a54dce00 .config console log report ci-android-49-kasan-gce
2017/08/29 14:51 https://android.googlesource.com/kernel/common android-4.9 5731c3033490 1d000225 .config console log report ci-android-49-kasan-gce
2017/08/24 00:10 https://android.googlesource.com/kernel/common android-4.9 34803e7c1c92 c3631fc7 .config console log report ci-android-49-kasan-gce
2017/08/23 06:44 https://android.googlesource.com/kernel/common android-4.9 34803e7c1c92 c3631fc7 .config console log report ci-android-49-kasan-gce
2017/08/20 17:41 https://android.googlesource.com/kernel/common android-4.9 6dda7ac61943 f238fbd4 .config console log report ci-android-49-kasan-gce
2017/08/03 13:42 https://android.googlesource.com/kernel/common android-4.9 ed323354ecec f5040a63 .config console log report ci-android-49-kasan-gce
* Struck through repros no longer work on HEAD.