From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1F583C2BA1A for ; Tue, 7 Apr 2020 20:06:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE2122074B for ; Tue, 7 Apr 2020 20:06:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727237AbgDGUGM (ORCPT ); Tue, 7 Apr 2020 16:06:12 -0400 Received: from mail-io1-f71.google.com ([209.85.166.71]:52657 "EHLO mail-io1-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726759AbgDGUGM (ORCPT ); Tue, 7 Apr 2020 16:06:12 -0400 Received: by mail-io1-f71.google.com with SMTP id c15so4084224iom.19 for ; Tue, 07 Apr 2020 13:06:11 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=CVr7biC8Q8ny8xqTK4oQ01HriXCO42SFK+8VQ4yBLaI=; b=X0kxCCdZufKkztR+yvV553kSLnkjtidIcOTeeuaMN147kHd0zzEp5v47Y9O3LDSqx5 npWG2CU96pz3MjGkaNi09Wsh9d/1IpzDA+zwLcNGUBUwOUuorcicFrfVZoZ7fXwOMYR3 pJhBzWVaMmkpPG8urquCqqYqcH2WaVj2grBp8Jbhao1I4IwxEgBHtDZoR4XC2FfrfJZD 0efWbjw4Cd99jsUQHuIeAIyhwNib2wpmXUBY6IL6/qewuDzxEwJ3Kii6RozQ5LkNIhUy PR1Dzu9W6dfnEiyvEUlV9QQ/KggYFWEYsUmuQh+AqDQ0jm+lQaa2fU6KVdiViEmJruMh Qejw== X-Gm-Message-State: AGi0PuYNkjUjjDXtHgPUuWxkZfLu52jUNv2k++Vd+fBbqE+kJXOqZzdC iu5b647IR1wr568Qt6/xckLEx7w1lb+50dsnS72Bgfwbc/Uu X-Google-Smtp-Source: APiQypLEmiJvkFyQVu85AAY7FU55UCjQdGuUhUhepwDKQKKhIiRSzLmMTBTr1d/QJCbZoIYVEwSXdx8WYAuarFwiy81M8MjFOCZ/ MIME-Version: 1.0 X-Received: by 2002:a02:b891:: with SMTP id p17mr3509083jam.124.1586289971178; Tue, 07 Apr 2020 13:06:11 -0700 (PDT) Date: Tue, 07 Apr 2020 13:06:11 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000003e2e5905a2b8ea2c@google.com> Subject: KASAN: slab-out-of-bounds Read in kvm_read_guest_page From: syzbot To: christoffer.dall@arm.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, maz@kernel.org, pbonzini@redhat.com, peterx@redhat.com, sean.j.christopherson@intel.com, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: bef7b2a7 Merge tag 'devicetree-for-5.7' of git://git.kerne.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=16e40efbe00000 kernel config: https://syzkaller.appspot.com/x/.config?x=91b674b8f0368e69 dashboard link: https://syzkaller.appspot.com/bug?extid=a65b3f8eec6b27650a25 compiler: gcc (GCC) 9.0.0 20181231 (experimental) userspace arch: i386 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14869db7e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10d2731fe00000 The bug was bisected to: commit 36947254e5f981aeeedab1c7dfa35fc34d330e80 Author: Sean Christopherson Date: Tue Feb 18 21:07:32 2020 +0000 KVM: Dynamically size memslot array based on number of used slots bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10a24a5de00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=12a24a5de00000 console output: https://syzkaller.appspot.com/x/log.txt?x=14a24a5de00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+a65b3f8eec6b27650a25@syzkaller.appspotmail.com Fixes: 36947254e5f9 ("KVM: Dynamically size memslot array based on number of used slots") L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details. ================================================================== BUG: KASAN: slab-out-of-bounds in search_memslots include/linux/kvm_host.h:1051 [inline] BUG: KASAN: slab-out-of-bounds in __gfn_to_memslot include/linux/kvm_host.h:1063 [inline] BUG: KASAN: slab-out-of-bounds in gfn_to_memslot arch/x86/kvm/../../../virt/kvm/kvm_main.c:1597 [inline] BUG: KASAN: slab-out-of-bounds in kvm_read_guest_page+0x4b5/0x4d0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2261 Read of size 8 at addr ffff8880953fd468 by task syz-executor431/6995 CPU: 1 PID: 6995 Comm: syz-executor431 Not tainted 5.6.0-syzkaller #0 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+0x188/0x20d lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd3/0x315 mm/kasan/report.c:374 __kasan_report.cold+0x35/0x4d mm/kasan/report.c:503 kasan_report+0x33/0x50 mm/kasan/common.c:648 search_memslots include/linux/kvm_host.h:1051 [inline] __gfn_to_memslot include/linux/kvm_host.h:1063 [inline] gfn_to_memslot arch/x86/kvm/../../../virt/kvm/kvm_main.c:1597 [inline] kvm_read_guest_page+0x4b5/0x4d0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2261 kvm_read_guest+0x51/0xd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2284 kvm_write_wall_clock arch/x86/kvm/x86.c:1721 [inline] kvm_set_msr_common+0xdf3/0x27c0 arch/x86/kvm/x86.c:2851 vmx_set_msr+0xa83/0x26a0 arch/x86/kvm/vmx/vmx.c:2183 __kvm_set_msr+0x15f/0x2d0 arch/x86/kvm/x86.c:1504 __msr_io arch/x86/kvm/x86.c:3262 [inline] msr_io+0x173/0x290 arch/x86/kvm/x86.c:3298 kvm_arch_vcpu_ioctl+0x1004/0x2c20 arch/x86/kvm/x86.c:4355 kvm_vcpu_ioctl+0x866/0xe60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3291 kvm_vcpu_compat_ioctl+0x1ab/0x350 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3334 __do_compat_sys_ioctl fs/ioctl.c:857 [inline] __se_compat_sys_ioctl fs/ioctl.c:808 [inline] __ia32_compat_sys_ioctl+0x23d/0x2b0 fs/ioctl.c:808 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe90 arch/x86/entry/common.c:396 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Allocated by task 6995: save_stack+0x1b/0x80 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:518 [inline] __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:491 kmalloc_node include/linux/slab.h:578 [inline] kvmalloc_node+0x61/0xf0 mm/util.c:574 kvmalloc include/linux/mm.h:733 [inline] kvzalloc include/linux/mm.h:741 [inline] kvm_dup_memslots arch/x86/kvm/../../../virt/kvm/kvm_main.c:1101 [inline] kvm_set_memslot+0x115/0x1530 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1118 __kvm_set_memory_region+0xcf7/0x1320 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1300 kvm_set_memory_region+0x29/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1321 kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1333 [inline] kvm_vm_ioctl+0x678/0x23e0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3604 kvm_vm_compat_ioctl+0x125/0x240 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3798 __do_compat_sys_ioctl fs/ioctl.c:857 [inline] __se_compat_sys_ioctl fs/ioctl.c:808 [inline] __ia32_compat_sys_ioctl+0x23d/0x2b0 fs/ioctl.c:808 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x270/0xe90 arch/x86/entry/common.c:396 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8880953fd000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1128 bytes inside of 2048-byte region [ffff8880953fd000, ffff8880953fd800) The buggy address belongs to the page: page:ffffea000254ff40 refcount:1 mapcount:0 mapping:00000000f2d13e61 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea000290dd48 ffffea00029c98c8 ffff8880aa000e00 raw: 0000000000000000 ffff8880953fd000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880953fd300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880953fd380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880953fd400: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc ^ ffff8880953fd480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880953fd500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches