KASAN: out-of-bounds Write in nested_sync_vmcs12_to

KASAN: out-of-bounds Write in nested_sync_vmcs12_to_shadow

Status: closed as dup on 2020/08/16 03:59
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+6ad11779184a3afe9f7e@syzkaller.appspotmail.com
First crash: 1791d, last: 1791d

Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: WARNING in sysfs_warn_dup (log)
Repro: syz .config

Fix bisection: failed (error log, bisect log)

▶ ▼ Duplicate of

Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported
general protection fault in syscall_return_slowpath kernel	syz	inconclusive	done	1	1745d	1831d

▶ ▼ Discussions (1)

Title	Replies (including bot)	Last reply
KASAN: out-of-bounds Write in nested_sync_vmcs12_to_shadow	1 (2)	2020/04/21 13:38

Sample crash report:

==================================================================
BUG: KASAN: out-of-bounds in copy_vmcs12_to_enlightened arch/x86/kvm/vmx/nested.c:1820 [inline]
BUG: KASAN: out-of-bounds in nested_sync_vmcs12_to_shadow+0x49e3/0x4a60 arch/x86/kvm/vmx/nested.c:2000
Write of size 2 at addr ffffc90004db72e8 by task syz-executor.4/8294

CPU: 1 PID: 8294 Comm: syz-executor.4 Not tainted 5.7.0-rc1-syzkaller #0
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+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0x5/0x315 mm/kasan/report.c:382
 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 copy_vmcs12_to_enlightened arch/x86/kvm/vmx/nested.c:1820 [inline]
 nested_sync_vmcs12_to_shadow+0x49e3/0x4a60 arch/x86/kvm/vmx/nested.c:2000
 </IRQ>


Memory state around the buggy address:
 ffffc90004db7180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90004db7200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90004db7280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                             ^
 ffffc90004db7300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90004db7380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================

Crashes (1):
Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	VM info	Assets (help?)	Manager	Title
2020/04/17 00:08	upstream	9786cab67457	c743fcb3	.config	console log	report	syz				ci-upstream-kasan-gce-386

* ~~Struck through~~ repros no longer work on HEAD.