syzbot


INFO: task hung in __do_page_fault

Status: public: reported C repro on 2019/04/12 00:01
Reported-by: syzbot+fc205e4925d4f926f3ff@syzkaller.appspotmail.com
First crash: 2048d, last: 1698d
Similar bugs (6)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 INFO: task hung in __do_page_fault C 1 1922d 1864d 0/2 public: reported C repro on 2019/04/14 00:00
linux-4.14 INFO: task hung in __do_page_fault C error 16 521d 1858d 0/1 upstream: reported C repro on 2019/04/19 08:53
upstream INFO: task hung in __do_page_fault (2) C done error 34 1748d 2032d 0/26 closed as invalid on 2022/02/08 10:55
android-49 INFO: task hung in __do_page_fault C 5 1689d 1863d 0/3 public: reported C repro on 2019/04/14 08:51
linux-4.19 INFO: task hung in __do_page_fault gfs2 C error 31 503d 1808d 0/1 upstream: reported C repro on 2019/06/08 06:01
upstream INFO: task hung in __do_page_fault fs 1 2227d 2227d 5/26 fixed on 2018/05/17 10:02

Sample crash report:
INFO: task syz-executor701:1890 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #22
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor701 D28592  1890   1889 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x22a/0x3c0 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:66 [inline]
 down_read+0x45/0xa0 kernel/locking/rwsem.c:26
 __do_page_fault+0x8a4/0xbb0 arch/x86/mm/fault.c:1359
 page_fault+0x42/0x50 arch/x86/entry/entry_64.S:1120
RIP: 6e0320:0x2d
RSP: 0001:00007ffc56d54710 EFLAGS: 00000001
INFO: task syz-executor701:1891 blocked for more than 140 seconds.
      Not tainted 4.14.134+ #22
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor701 D28648  1891   1889 0x80000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3498
 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
 rwsem_down_read_failed+0x22a/0x3c0 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:66 [inline]
 down_read+0x45/0xa0 kernel/locking/rwsem.c:26
 exit_mm kernel/exit.c:511 [inline]
 do_exit+0x575/0x2a20 kernel/exit.c:861

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.+}, at: [<        (ptrval)>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
2 locks held by getty/1760:
 #0:  (&tty->ldisc_sem){++++}, at: [<        (ptrval)>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:284
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<        (ptrval)>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
1 lock held by syz-executor701/1890:
 #0:  (&mm->mmap_sem){++++}, at: [<        (ptrval)>] __do_page_fault+0x8a4/0xbb0 arch/x86/mm/fault.c:1359
1 lock held by syz-executor701/1891:
 #0:  (&mm->mmap_sem){++++}, at: [<        (ptrval)>] exit_mm kernel/exit.c:511 [inline]
 #0:  (&mm->mmap_sem){++++}, at: [<        (ptrval)>] do_exit+0x575/0x2a20 kernel/exit.c:861

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

NMI backtrace for cpu 1
CPU: 1 PID: 23 Comm: khungtaskd Not tainted 4.14.134+ #22
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xca/0x134 lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1892 Comm: syz-executor701 Not tainted 4.14.134+ #22
task:         (ptrval) task.stack:         (ptrval)
RIP: 0010:mark_lock+0xc/0xfc0 kernel/locking/lockdep.c:3158
RSP: 0018:ffff8881ca007880 EFLAGS: 00000046
RAX: dffffc0000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000002 RSI: ffff8881cae96658 RDI: ffff8881cae95e00
RBP: ffff8881ca007a58 R08: 0000000000000001 R09: 0000000000000001
R10: ffff8881cae96658 R11: 0000000000000359 R12: ffff8881cae9667a
R13: 0000000000040359 R14: ffff8881cae95e00 R15: 0000000000000000
FS:  00007f9b20323700(0000) GS:ffff8881dba00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000206c000 CR3: 00000001ca606002 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 mark_irqflags kernel/locking/lockdep.c:3082 [inline]
 __lock_acquire+0xd5e/0x42e0 kernel/locking/lockdep.c:3444
Code: 31 c0 5b 5d 41 5c 41 5d 41 5e 41 5f c3 4c 89 ff e8 3a 0f 34 00 eb d7 0f 1f 84 00 00 00 00 00 48 b8 00 00 00 00 00 fc ff df 41 57 <89> d1 41 89 d7 41 56 49 89 fe 41 55 4c 8d 6e 20 4c 89 ea 41 54 

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/07/27 22:51 android-4.14 54fa720a6f32 c85e1c5b .config console log report syz C ci-android-414-kasan-gce-root
2018/10/27 02:15 android-4.14 4ed22187defd a8292de9 .config console log report syz C ci-android-414-kasan-gce-root
2018/10/11 16:57 android-4.14 b7e40c3d444a 5f818b4b .config console log report syz C ci-android-414-kasan-gce-root
2019/09/26 09:20 android-4.14 d649ef04c3ed 24d405a3 .config console log report ci-android-414-kasan-gce-root
2019/05/09 16:19 android-4.14 bedc41064f46 6fc130d3 .config console log report ci-android-414-kasan-gce-root
2019/04/11 03:48 android-4.14 95196d1bad3f e955ac50 .config console log report ci-android-414-kasan-gce-root
2019/02/20 19:21 android-4.14 9195330d3d49 c95f0707 .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.