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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id CCF08C433EF for ; Fri, 18 Feb 2022 11:39:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234944AbiBRLjY (ORCPT ); Fri, 18 Feb 2022 06:39:24 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:46238 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234886AbiBRLjA (ORCPT ); Fri, 18 Feb 2022 06:39:00 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 0608231903 for ; Fri, 18 Feb 2022 03:37:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1645184253; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=kRz2HhmPOJqUdEguD6ineI0jgT8YXoXhvMfK4d0/iRk=; b=iZ8JXWnJegYuprPViiFj2S44PQ5iqRXJGJHJRk8YfDqhz7va0cVkg6kWlG4cwcBN6x2pCA 9fazozbtoSl1s2Rhbqr0EH5/lxR42g1nYTgNTZkz85TOWE3VsRg/zbtTgvTKxOBhsXjZgi V3ZipINj24mTyr6QYckhe1LKrV7RcMo= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-204-PtD2ndtRPBuM21nQcZxq1g-1; Fri, 18 Feb 2022 06:37:32 -0500 X-MC-Unique: PtD2ndtRPBuM21nQcZxq1g-1 Received: by mail-ed1-f69.google.com with SMTP id j9-20020a056402238900b004128085d906so4495645eda.19 for ; Fri, 18 Feb 2022 03:37:32 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=kRz2HhmPOJqUdEguD6ineI0jgT8YXoXhvMfK4d0/iRk=; b=EMqWpWz3Upd9suItMMjhKj7b0dau2/UNvE5leSS258/8FWdyrjKOwyUYX+OjyVDEv0 RloCer3LqC2ssWBVqTcXXnCepKJnvxtNfpPU6XzxW8orCRWqUnj+M8fasydn/htSWd1j wGAe9VsWNcC2PD+S2IjCM3G5MD2DX64tk7ig+5b+9OE2GvkW6JJQFakXEeWfIePvm0jI JsnSxyTpzEkDypKTq/wCRzwvDca/LLRft05UIYEYt5+sl48SMnpjyXyM86pPb8akz24H fNs7uNhlh8ZcVaOmkChybyFYiRlIIf6sh4fZqu44pfDU/7i0m+GdsZDEJtNq5gfvnJVv /ehg== X-Gm-Message-State: AOAM530FgW6+vTbs2CLvg+kPjGeEdf/at2in6qtw5kZA4/my9CqNEr9o wfKMYcQAjZN9uuCyUzWMUklQuQeruDhiBNrXLKWiENj90rwR0nDyA6f9oaGjkrBIShYDOIPzI4Y 9myvO8YYZwDs8 X-Received: by 2002:a17:906:f293:b0:6b6:bc93:f01f with SMTP id gu19-20020a170906f29300b006b6bc93f01fmr5656032ejb.743.1645184251241; Fri, 18 Feb 2022 03:37:31 -0800 (PST) X-Google-Smtp-Source: ABdhPJyumwEeTQqcko1h2tOqCFdEjZvTGldy8JfDmmW/0pXvLQMU7H6ovgQWyZGrpbpB4r5tpsNPFQ== X-Received: by 2002:a17:906:f293:b0:6b6:bc93:f01f with SMTP id gu19-20020a170906f29300b006b6bc93f01fmr5656019ejb.743.1645184251001; Fri, 18 Feb 2022 03:37:31 -0800 (PST) Received: from redhat.com ([2.55.156.211]) by smtp.gmail.com with ESMTPSA id z18sm2209291ejl.78.2022.02.18.03.37.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 18 Feb 2022 03:37:30 -0800 (PST) Date: Fri, 18 Feb 2022 06:37:26 -0500 From: "Michael S. Tsirkin" To: syzbot Cc: jasowang@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, virtualization@lists.linux-foundation.org Subject: Re: [syzbot] kernel BUG in vhost_get_vq_desc Message-ID: <20220218063352-mutt-send-email-mst@kernel.org> References: <00000000000070ac6505d7d9f7a8@google.com> <0000000000003b07b305d840b30f@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0000000000003b07b305d840b30f@google.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Thu, Feb 17, 2022 at 05:21:20PM -0800, syzbot wrote: > syzbot has found a reproducer for the following issue on: > > HEAD commit: f71077a4d84b Merge tag 'mmc-v5.17-rc1-2' of git://git.kern.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=104c04ca700000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a78b064590b9f912 > dashboard link: https://syzkaller.appspot.com/bug?extid=3140b17cb44a7b174008 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1362e232700000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11373a6c700000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+3140b17cb44a7b174008@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > kernel BUG at drivers/vhost/vhost.c:2335! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 3597 Comm: vhost-3596 Not tainted 5.17.0-rc4-syzkaller-00054-gf71077a4d84b #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:vhost_get_vq_desc+0x1d43/0x22c0 drivers/vhost/vhost.c:2335 > Code: 00 00 00 48 c7 c6 20 2c 9d 8a 48 c7 c7 98 a6 8e 8d 48 89 ca 48 c1 e1 04 48 01 d9 e8 b7 59 28 fd e9 74 ff ff ff e8 5d c8 a1 fa <0f> 0b e8 56 c8 a1 fa 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df > RSP: 0018:ffffc90001d1fb88 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 > RDX: ffff8880234b0000 RSI: ffffffff86d715c3 RDI: 0000000000000003 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 > R10: ffffffff86d706bc R11: 0000000000000000 R12: ffff888072c24d68 > R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888072c24bb0 > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000002 CR3: 000000007902c000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > vhost_vsock_handle_tx_kick+0x277/0xa20 drivers/vhost/vsock.c:522 > vhost_worker+0x23d/0x3d0 drivers/vhost/vhost.c:372 > kthread+0x2e9/0x3a0 kernel/kthread.c:377 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 I don't see how this can trigger normally so I'm assuming another case of use after free. > > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:vhost_get_vq_desc+0x1d43/0x22c0 drivers/vhost/vhost.c:2335 > Code: 00 00 00 48 c7 c6 20 2c 9d 8a 48 c7 c7 98 a6 8e 8d 48 89 ca 48 c1 e1 04 48 01 d9 e8 b7 59 28 fd e9 74 ff ff ff e8 5d c8 a1 fa <0f> 0b e8 56 c8 a1 fa 48 8b 54 24 18 48 b8 00 00 00 00 00 fc ff df > RSP: 0018:ffffc90001d1fb88 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 > RDX: ffff8880234b0000 RSI: ffffffff86d715c3 RDI: 0000000000000003 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 > R10: ffffffff86d706bc R11: 0000000000000000 R12: ffff888072c24d68 > R13: 0000000000000000 R14: dffffc0000000000 R15: ffff888072c24bb0 > FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000002 CR3: 000000007902c000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400