KASAN: use-after-free Read in vmx_vcpu_load

Status: auto-closed as invalid on 2019/03/20 11:42
Subsystems: kvm-x86
[Documentation on labels]
Reported-by: syzbot+1ff78ee6b7dd52919ab9@syzkaller.appspotmail.com
First crash: 2925d, last: 2883d
▶ ▼ Duplicate bugs (1)
Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
BUG: corrupted list in vmx_vcpu_load kvm-x86 8 7 2896d 2913d 0/29 closed as dup on 2019/02/20 16:59
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in vmx_vcpu_load 0 (1) 2018/08/14 14:33

Sample crash report:
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000006
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cfc28 R14: 00000000004bfd60 R15: 0000000000000000
==================================================================
BUG: KASAN: use-after-free in vmx_vcpu_load+0xfde/0x1030 arch/x86/kvm/vmx.c:3110
Read of size 8 at addr ffff8801d3d1e660 by task syz-executor1/14179

CPU: 1 PID: 14179 Comm: syz-executor1 Not tainted 4.19.0-rc4+ #248
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+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
 vmx_vcpu_load+0xfde/0x1030 arch/x86/kvm/vmx.c:3110
 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
 preempt_schedule_irq+0x87/0x110 kernel/sched/core.c:3700
 retint_kernel+0x1b/0x2d
RIP: 0010:depot_save_stack+0x8/0x470 lib/stackdepot.c:219
Code: 00 00 c3 48 89 0c d5 40 5b da 8b b8 01 00 00 00 48 c7 07 00 00 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 <41> 55 49 89 fd 41 54 53 48 83 ec 10 8b 3f 65 48 8b 04 25 28 00 00
RSP: 0018:ffff8801c0e9f390 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000011 RBX: 00000000006000c0 RCX: ffffffffffffffff
RDX: 0000000000000010 RSI: 00000000006000c0 RDI: ffff8801c0e9f3b0
RBP: ffff8801c0e9f3a0 R08: 0000000000000000 R09: ffffed003b5e4732
R10: ffffed003b5e4732 R11: ffff8801daf23993 R12: ffff8801da972a80
R13: ffff8801cb7813e8 R14: 0000000000000000 R15: ffff8801cb7813e7
 save_stack+0xa9/0xd0 mm/kasan/kasan.c:454
 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
 alloc_inode+0xb2/0x190 fs/inode.c:212
 new_inode_pseudo+0x71/0x1a0 fs/inode.c:903
 new_inode+0x1c/0x40 fs/inode.c:932
 debugfs_get_inode+0x19/0x120 fs/debugfs/inode.c:37
 __debugfs_create_file+0xb5/0x400 fs/debugfs/inode.c:352
 debugfs_create_file+0x57/0x70 fs/debugfs/inode.c:399
 kvm_create_vm_debugfs arch/x86/kvm/../../../virt/kvm/kvm_main.c:620 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3214 [inline]
 kvm_dev_ioctl+0xbe0/0x1b10 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3241
 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
RIP: 0033:0x457679
Code: 1d 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f9200d5fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f9200d606d4 RCX: 0000000000457679
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000006
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004cfc28 R14: 00000000004bfd60 R15: 0000000000000000

Allocated by task 14179:
 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 14178:
 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 ffff8801d3d18e80
 which belongs to the cache kvm_vcpu(65:syz1) of size 23872
The buggy address is located 22496 bytes inside of
 23872-byte region [ffff8801d3d18e80, ffff8801d3d1ebc0)
The buggy address belongs to the page:
page:ffffea00074f4600 count:1 mapcount:0 mapping:ffff8801d2a57600 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0006ea3608 ffffea000737ac08 ffff8801d2a57600
raw: 0000000000000000 ffff8801d3d18e80 0000000100000001 ffff880193a9e1c0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff880193a9e1c0

Memory state around the buggy address:
 ffff8801d3d1e500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d3d1e580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d3d1e600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8801d3d1e680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d3d1e700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/09/21 11:41 upstream 234b69e3e089 37079712 .config console log report ci-upstream-kasan-gce-root
2018/09/10 12:29 upstream 11da3a7f84f1 6b5120a4 .config console log report ci-upstream-kasan-gce
2018/09/07 23:54 upstream a49a9dcce802 69cfeb80 .config console log report ci-upstream-kasan-gce
2018/09/06 17:57 upstream b36fdc6853a3 0bb7a7eb .config console log report ci-upstream-kasan-gce-root
2018/08/26 15:10 upstream 2923b27e5424 758cd203 .config console log report ci-upstream-kasan-gce-root
2018/08/26 11:13 upstream 2923b27e5424 758cd203 .config console log report ci-upstream-kasan-gce-root
2018/08/23 07:31 upstream 899fbc33fd77 95b5c82b .config console log report ci-upstream-kasan-gce-root
2018/08/21 17:42 upstream 778a33959a8a 95b5c82b .config console log report ci-upstream-kasan-gce-root
2018/08/20 08:39 upstream 2ad0d5269970 2dc4378f .config console log report ci-upstream-kasan-gce-root
2018/09/16 22:16 upstream 7876320f8880 a343a400 .config console log report ci-upstream-kasan-gce-386
2018/08/30 22:13 upstream 58c3f14f86c9 938220fd .config console log report ci-upstream-kasan-gce-386
2018/08/20 09:48 linux-next 812667578394 2dc4378f .config console log report ci-upstream-linux-next-kasan-gce-root
2018/08/09 16:43 linux-next 1c2f2531cf8b 1fb62d58 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.