syzbot


BUG: unable to handle kernel paging request in refcount_inc_not_zero_checked

Status: closed as dup on 2018/10/11 14:33
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+e593df3bb8f541d497b9@syzkaller.appspotmail.com
First crash: 1965d, last: 1909d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
WARNING: refcount bug in kvm_vm_ioctl kvm syz 13 1852d 1965d
Discussions (1)
Title Replies (including bot) Last reply
BUG: unable to handle kernel paging request in refcount_inc_not_zero_checked 1 (2) 2018/10/11 14:33

Sample crash report:
BUG: unable to handle kernel paging request at ffffc9001260b6b8
PGD 1da95a067 P4D 1da95a067 PUD 1da95b067 PMD 1d2f95067 PTE 0
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 17843 Comm: syz-executor3 Not tainted 4.20.0-rc5+ #265
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:182 [inline]
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:31 [inline]
RIP: 0010:atomic_read include/asm-generic/atomic-instrumented.h:22 [inline]
RIP: 0010:refcount_inc_not_zero_checked+0xbb/0x2f0 lib/refcount.c:120
Code: e7 e8 a9 59 30 fe 4c 89 e0 48 c1 e8 03 0f b6 14 18 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 0b 02 00 00 49 8d 5d c0 <45> 8b 3c 24 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f
RSP: 0018:ffff8881b762f690 EFLAGS: 00010246
RAX: 0000000000000003 RBX: ffff8881b762f708 RCX: ffffffff83928a57
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffc9001260b6b8
RBP: ffff8881b762f770 R08: fffff520024c16d8 R09: fffff520024c16d7
R10: fffff520024c16d7 R11: ffffc9001260b6bb R12: ffffc9001260b6b8
R13: ffff8881b762f748 R14: ffffffff894b6e20 R15: ffff8881d7c8f280
kobject: 'loop1' (000000008fcd6124): kobject_uevent_env
FS:  0000000000000000(0000) GS:ffff8881daf00000(0063) knlGS:00000000f5fa1b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffc9001260b6b8 CR3: 00000001cc93b000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
kobject: 'loop1' (000000008fcd6124): fill_kobj_path: path = '/devices/virtual/block/loop1'
Call Trace:
 refcount_inc_checked+0x15/0x70 lib/refcount.c:153
 kvm_get_kvm arch/x86/kvm/../../../virt/kvm/kvm_main.c:763 [inline]
 kvm_ioctl_create_device arch/x86/kvm/../../../virt/kvm/kvm_main.c:2930 [inline]
 kvm_vm_ioctl+0xedf/0x1d60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3122
 kvm_vm_compat_ioctl+0x143/0x430 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3178
 __do_compat_sys_ioctl fs/compat_ioctl.c:1052 [inline]
 __se_compat_sys_ioctl fs/compat_ioctl.c:998 [inline]
 __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:998
 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
 do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fa5a29
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5fa10cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 0000000000000010 RCX: 00000000c00caee0
RDX: 0000000020000340 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: ffffc9001260b6b8
---[ end trace fe18e9c76db671ef ]---
RIP: 0010:__read_once_size include/linux/compiler.h:182 [inline]
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:31 [inline]
RIP: 0010:atomic_read include/asm-generic/atomic-instrumented.h:22 [inline]
RIP: 0010:refcount_inc_not_zero_checked+0xbb/0x2f0 lib/refcount.c:120
Code: e7 e8 a9 59 30 fe 4c 89 e0 48 c1 e8 03 0f b6 14 18 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 0b 02 00 00 49 8d 5d c0 <45> 8b 3c 24 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f
RSP: 0018:ffff8881b762f690 EFLAGS: 00010246
RAX: 0000000000000003 RBX: ffff8881b762f708 RCX: ffffffff83928a57
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffc9001260b6b8
RBP: ffff8881b762f770 R08: fffff520024c16d8 R09: fffff520024c16d7
R10: fffff520024c16d7 R11: ffffc9001260b6bb R12: ffffc9001260b6b8
R13: ffff8881b762f748 R14: ffffffff894b6e20 R15: ffff8881d7c8f280
FS:  0000000000000000(0000) GS:ffff8881daf00000(0063) knlGS:00000000f5fa1b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffffc9001260b6b8 CR3: 00000001cc93b000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/12/05 06:05 upstream 0072a0c14d5b f162ad97 .config console log report ci-upstream-kasan-gce-386
2018/10/09 22:51 linux-next 570b7bdeaf18 8b311eaf .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.