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=-8.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_HELO_NONE,SPF_PASS 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 6BC40C433EF for ; Sat, 4 Sep 2021 18:58:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46CE160EE3 for ; Sat, 4 Sep 2021 18:58:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232280AbhIDS7W (ORCPT ); Sat, 4 Sep 2021 14:59:22 -0400 Received: from mail-il1-f197.google.com ([209.85.166.197]:43590 "EHLO mail-il1-f197.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231138AbhIDS7V (ORCPT ); Sat, 4 Sep 2021 14:59:21 -0400 Received: by mail-il1-f197.google.com with SMTP id i5-20020a056e0212c500b0022b41c6554bso575605ilm.10 for ; Sat, 04 Sep 2021 11:58:19 -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=CWgZv89raI6FjW1i2Zg7mi6RNJ73KbtI0Q8N7x6OQqI=; b=U5YAZsZoWcHUNBUf3YzC9+fFXDJlBvTRV457w/w6rZrGjeZ+5Tpmp/SL+wao2eJzfq vm3Up6VxrwAYrzciEV6OKaoF4knBFjmAE5G3BYlMXBbt+2uoj3ITxb26/ZlT3s5QYqqK FZyA9KjR7Jlm7zxQjWjwhBA4UKjsKDhmef4uYzWGIex1cLHzeHHRzyx1JS2wkGIfxe9j uRVg1cFh/GNphQ76k1veI8fXehhsRd0SINal+n9BQv2dX+Dy+PlbqBdC205izYNWQg6M HXoxbsN5AZsU3MwAjtKw2KdFHmQIaqllQZQfbruu8FrmgQFpgE34blwwlrErUwZjx9lp 8gFA== X-Gm-Message-State: AOAM533wVePGgTIi8uVsJf7IZdSHI7QU1RRVf0oyeCmexSBWd3416WJx I5oLLKxT4VMHoPPUVXubdb7CFHpWrWqw4kCgLUwRVXOakdUq X-Google-Smtp-Source: ABdhPJytlHOirhofFAXXQvRYfU1sYZUwYhGV6rkm8N9DJ0T55F8O/Mntcq6fgj7zyV9k+LNWWaltRMrLgA3d00cCCMZvPbULXVbA MIME-Version: 1.0 X-Received: by 2002:a6b:b586:: with SMTP id e128mr3810502iof.37.1630781899715; Sat, 04 Sep 2021 11:58:19 -0700 (PDT) Date: Sat, 04 Sep 2021 11:58:19 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000d6b66705cb2fffd4@google.com> Subject: [syzbot] upstream test error: KFENCE: use-after-free in kvm_fastop_exception From: syzbot To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, viro@zeniv.linux.org.uk Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Hello, syzbot found the following issue on: HEAD commit: 835d31d319d9 Merge tag 'media/v5.15-1' of git://git.kernel.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=1189fe49300000 kernel config: https://syzkaller.appspot.com/x/.config?x=d1a7a34dc082816f dashboard link: https://syzkaller.appspot.com/bug?extid=d08efd12a2905a344291 compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+d08efd12a2905a344291@syzkaller.appspotmail.com ================================================================== BUG: KFENCE: use-after-free read in kvm_fastop_exception+0xf6d/0x105b Use-after-free read at 0xffff88823bc0c020 (in kfence-#5): kvm_fastop_exception+0xf6d/0x105b d_lookup+0xd8/0x170 fs/dcache.c:2370 lookup_dcache+0x1e/0x130 fs/namei.c:1520 __lookup_hash+0x29/0x180 fs/namei.c:1543 kern_path_locked+0x17e/0x320 fs/namei.c:2567 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 kfence-#5 [0xffff88823bc0c000-0xffff88823bc0cfff, size=4096, cache=names_cache] allocated by task 22: getname_kernel+0x4e/0x370 fs/namei.c:226 kern_path_locked+0x71/0x320 fs/namei.c:2558 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 freed by task 22: putname.part.0+0xe1/0x120 fs/namei.c:270 putname include/linux/err.h:41 [inline] filename_parentat fs/namei.c:2547 [inline] kern_path_locked+0xc2/0x320 fs/namei.c:2558 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 CPU: 1 PID: 22 Comm: kdevtmpfs Not tainted 5.14.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvm_fastop_exception+0xf6d/0x105b Code: d3 ed e9 14 1b 6d f8 49 8d 0e 48 83 e1 f8 4c 8b 21 41 8d 0e 83 e1 07 c1 e1 03 49 d3 ec e9 6a 28 6d f8 49 8d 4d 00 48 83 e1 f8 <4c> 8b 21 41 8d 4d 00 83 e1 07 c1 e1 03 49 d3 ec e9 5a 32 6d f8 bd RSP: 0018:ffffc90000fe7ae8 EFLAGS: 00010282 RAX: 0000000035736376 RBX: ffff88803b141cc0 RCX: ffff88823bc0c020 RDX: ffffed100762839f RSI: 0000000000000004 RDI: 0000000000000007 RBP: 0000000000000004 R08: 0000000000000000 R09: ffff88803b141cf0 R10: ffffed100762839e R11: 0000000000000000 R12: ffff88823bc0c020 R13: ffff88823bc0c020 R14: ffff88803b141cf0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff88823bc0c020 CR3: 0000000029892000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: d_lookup+0xd8/0x170 fs/dcache.c:2370 lookup_dcache+0x1e/0x130 fs/namei.c:1520 __lookup_hash+0x29/0x180 fs/namei.c:1543 kern_path_locked+0x17e/0x320 fs/namei.c:2567 handle_remove+0xa2/0x5fe drivers/base/devtmpfs.c:312 handle drivers/base/devtmpfs.c:382 [inline] devtmpfs_work_loop drivers/base/devtmpfs.c:395 [inline] devtmpfsd+0x1b9/0x2a3 drivers/base/devtmpfs.c:437 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ================================================================== ---------------- Code disassembly (best guess): 0: d3 ed shr %cl,%ebp 2: e9 14 1b 6d f8 jmpq 0xf86d1b1b 7: 49 8d 0e lea (%r14),%rcx a: 48 83 e1 f8 and $0xfffffffffffffff8,%rcx e: 4c 8b 21 mov (%rcx),%r12 11: 41 8d 0e lea (%r14),%ecx 14: 83 e1 07 and $0x7,%ecx 17: c1 e1 03 shl $0x3,%ecx 1a: 49 d3 ec shr %cl,%r12 1d: e9 6a 28 6d f8 jmpq 0xf86d288c 22: 49 8d 4d 00 lea 0x0(%r13),%rcx 26: 48 83 e1 f8 and $0xfffffffffffffff8,%rcx * 2a: 4c 8b 21 mov (%rcx),%r12 <-- trapping instruction 2d: 41 8d 4d 00 lea 0x0(%r13),%ecx 31: 83 e1 07 and $0x7,%ecx 34: c1 e1 03 shl $0x3,%ecx 37: 49 d3 ec shr %cl,%r12 3a: e9 5a 32 6d f8 jmpq 0xf86d3299 3f: bd .byte 0xbd --- This report 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 issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.