KASAN: use-after-free Read in __loaded_vmcs_clear

Status: auto-closed as invalid on 2019/03/08 21:37
Subsystems: kvm-x86
[Documentation on labels]
Reported-by: syzbot+c26aa916bc6caa4853dd@syzkaller.appspotmail.com
First crash: 2916d, last: 2897d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in __loaded_vmcs_clear 0 (1) 2018/08/21 15:24

Sample crash report:
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000009300a8
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000009300ac
R13: 00007ffd574ec40f R14: 00007f0332d129c0 R15: 0000000000000000
==================================================================
BUG: KASAN: use-after-free in __list_del_entry_valid+0xf1/0xf3 lib/list_debug.c:51
Read of size 8 at addr ffff880176346ea0 by task syz-executor1/28115

CPU: 0 PID: 28115 Comm: syz-executor1 Not tainted 4.19.0-rc2+ #9
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __list_del_entry_valid+0xf1/0xf3 lib/list_debug.c:51
 __list_del_entry include/linux/list.h:117 [inline]
 list_del include/linux/list.h:125 [inline]
 __loaded_vmcs_clear+0x16c/0x690 arch/x86/kvm/vmx.c:2199
 flush_smp_call_function_queue+0x1d2/0x640 kernel/smp.c:243
 generic_smp_call_function_single_interrupt+0x13/0x2b kernel/smp.c:192
 smp_call_function_single_interrupt+0x12f/0x650 arch/x86/kernel/smp.c:296
 call_function_single_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:886
 </IRQ>
RIP: 0010:arch_local_irq_restore+0x4a/0x52 arch/x86/include/asm/paravirt.h:788
Code: 48 c1 ea 03 80 3c 02 00 74 05 e8 89 2f 0a fa 48 83 3d 29 22 9a 01 00 75 07 e8 fa c8 c6 f9 0f 0b e8 f3 c8 c6 f9 48 89 df 57 9d <0f> 1f 44 00 00 5b 5d c3 4c 89 45 d0 e8 3d 2f 0a fa 4c 8b 45 d0 e9
RSP: 0018:ffff8801762fed10 EFLAGS: 00000212 ORIG_RAX: ffffffffffffff04
RAX: 0000000000040000 RBX: 0000000000000212 RCX: ffffc90004ae2000
RDX: 0000000000040000 RSI: ffffffff87b807cd RDI: 0000000000000212
RBP: ffff8801762fed18 R08: ffff88018877a6c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000212
R13: 0000000000000200 R14: 0000000000000000 R15: ffffffff895229e0
 dump_stack+0x26a/0x2b4 lib/dump_stack.c:118
 vmwrite_error+0x4c/0x60 arch/x86/kvm/vmx.c:2364
 __vmcs_writel arch/x86/kvm/vmx.c:2374 [inline]
 vmcs_writel arch/x86/kvm/vmx.c:2414 [inline]
 vmx_vcpu_load+0xd10/0x1030 arch/x86/kvm/vmx.c:3095
 kvm_arch_vcpu_load+0x247/0x970 arch/x86/kvm/x86.c:3106
 kvm_sched_in+0x82/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3975
 __fire_sched_in_preempt_notifiers kernel/sched/core.c:2481 [inline]
 fire_sched_in_preempt_notifiers kernel/sched/core.c:2487 [inline]
 finish_task_switch+0x56e/0x900 kernel/sched/core.c:2679
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x874/0x1ed0 kernel/sched/core.c:3473
 schedule+0xfe/0x460 kernel/sched/core.c:3517
 freezable_schedule include/linux/freezer.h:172 [inline]
 futex_wait_queue_me+0x3f9/0x840 kernel/futex.c:2530
 futex_wait+0x45c/0xa50 kernel/futex.c:2645
 do_futex+0x31a/0x26d0 kernel/futex.c:3528
 __do_sys_futex kernel/futex.c:3589 [inline]
 __se_sys_futex kernel/futex.c:3557 [inline]
 __x64_sys_futex+0x472/0x6a0 kernel/futex.c:3557
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: fd b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0332d11cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00000000009300a8 RCX: 0000000000457099
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000009300a8
RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000009300ac
R13: 00007ffd574ec40f R14: 00007f0332d129c0 R15: 0000000000000000

Allocated by task 28115:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554
 kmem_cache_zalloc include/linux/slab.h:697 [inline]
 vmx_create_vcpu+0xcf/0x25e0 arch/x86/kvm/vmx.c:10954
 kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8452
 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2476 [inline]
 kvm_vm_ioctl+0x470/0x1d40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2977
 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

Freed by task 28109:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x83/0x290 mm/slab.c:3756
 vmx_free_vcpu+0x26b/0x300 arch/x86/kvm/vmx.c:10948
 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8438 [inline]
 kvm_free_vcpus arch/x86/kvm/x86.c:8888 [inline]
 kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:8985
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline]
 kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773
 kvm_vcpu_release+0x7b/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2407
 __fput+0x385/0xa30 fs/file_table.c:278
 ____fput+0x15/0x20 fs/file_table.c:309
 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff880176341700
 which belongs to the cache kvm_vcpu of size 23872
The buggy address is located 22432 bytes inside of
 23872-byte region [ffff880176341700, ffff880176347440)
The buggy address belongs to the page:
page:ffffea0005d8d000 count:1 mapcount:0 mapping:ffff8801d792c200 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea00063a7e08 ffffea0005c7f208 ffff8801d792c200
raw: 0000000000000000 ffff880176341700 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff880176346d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff880176346e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff880176346e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff880176346f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff880176346f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/09/09 21:36 upstream 9a5682765a2e 6b5120a4 .config console log report ci-upstream-kasan-gce-selinux-root
2018/08/30 11:05 upstream ff69279a44e9 6c7e9d3d .config console log report ci-upstream-kasan-gce
2018/08/26 01:04 upstream b8dcdab36f53 76e7c3df .config console log report ci-upstream-kasan-gce
2018/08/21 01:34 upstream cc26ebbebde8 95b5c82b .config console log report ci-upstream-kasan-gce-root
2018/09/02 22:12 linux-next a880148cb2af a4718693 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.