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=-0.4 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 74340ECDFB8 for ; Thu, 19 Jul 2018 23:19:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21F3020673 for ; Thu, 19 Jul 2018 23:19:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 21F3020673 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730598AbeGTAEX (ORCPT ); Thu, 19 Jul 2018 20:04:23 -0400 Received: from mail-it0-f72.google.com ([209.85.214.72]:42799 "EHLO mail-it0-f72.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728912AbeGTAEX (ORCPT ); Thu, 19 Jul 2018 20:04:23 -0400 Received: by mail-it0-f72.google.com with SMTP id p21-v6so7361088itc.7 for ; Thu, 19 Jul 2018 16:19:02 -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=EBPgTsWP65PxgfcpcAOJjQgVsR4d1WmmAa61v6Ldkvk=; b=Dl8PPcgLRyMchNb1+hzDqQyYWrMoehPrsrNePAHocoYzHrxFXJmKWII6KyaFziahQt xK3XZI/BtaHvKUVd688mxgRJGgKomUC5s6vfGbI4/lrX4A2ydBuFDASot4GM3F6CTmOx fXq4PpIL6fxkS3wjBYwL62HgComCIiPV2ObT8Ouoo7uozcfVLvkg8LJ3je0by3Jif3uB HtStUMzBgrLnpFJyG3FuDd4AfHsDtMPzkwLhzv3WBEp0F556KshVfxeNzNbDlgvIh8Kd 3VE12T89fA2ug591Z+MjIKYOEuJJlZiJELLfjSaiDTuc4EcZ48U92/vqtJ4q1jmofzrQ iL0w== X-Gm-Message-State: AOUpUlE0cHF9v/DsGEcLgR7xK/AhS7wUdFj5zMX3PLkJiPpCLrBQBNKd vMzmdgMqqQtjLBe/bAeF9Ie/ndqF1dd2NTBDiogZcSUiLEww X-Google-Smtp-Source: AAOMgpfNd60sHsYlP22ot7WG5XO7wd48ArrK1c9C7/fkwWt+qRAQAJM04p98GZKWj5kWSm83diMm6fGf4ADyiKh0AoMwYBvI+EsH MIME-Version: 1.0 X-Received: by 2002:a24:646:: with SMTP id 67-v6mr29033itv.54.1532042342476; Thu, 19 Jul 2018 16:19:02 -0700 (PDT) Date: Thu, 19 Jul 2018 16:19:02 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000009ab6cf0571626794@google.com> Subject: KASAN: use-after-free Read in _copy_from_iter 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"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 1c34981993da Add linux-next specific files for 20180719 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1658732c400000 kernel config: https://syzkaller.appspot.com/x/.config?x=7002497517b09aec dashboard link: https://syzkaller.appspot.com/bug?extid=467050c1ce275af2a5b8 compiler: gcc (GCC) 8.0.1 20180413 (experimental) syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=15983b68400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13dc4d1c400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+467050c1ce275af2a5b8@syzkaller.appspotmail.com random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) random: sshd: uninitialized urandom read (32 bytes read) ================================================================== BUG: KASAN: use-after-free in memcpy include/linux/string.h:345 [inline] BUG: KASAN: use-after-free in _copy_from_iter+0x9ea/0x1090 lib/iov_iter.c:701 Read of size 21 at addr ffff8801abd90360 by task kworker/0:2/2142 CPU: 0 PID: 2142 Comm: kworker/0:2 Not tainted 4.18.0-rc5-next-20180719+ #11 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events p9_write_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 memcpy+0x23/0x50 mm/kasan/kasan.c:302 memcpy include/linux/string.h:345 [inline] _copy_from_iter+0x9ea/0x1090 lib/iov_iter.c:701 copy_page_from_iter+0x576/0x890 lib/iov_iter.c:857 pipe_write+0x235/0xeb0 fs/pipe.c:429 call_write_iter include/linux/fs.h:1826 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6af/0x9d0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 kernel_write+0xab/0x120 fs/read_write.c:526 p9_fd_write net/9p/trans_fd.c:427 [inline] p9_write_work+0x6f1/0xd50 net/9p/trans_fd.c:476 process_one_work+0xc73/0x1ba0 kernel/workqueue.c:2153 worker_thread+0x189/0x13c0 kernel/workqueue.c:2296 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Allocated by task 4465: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553 __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x14e/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:518 [inline] p9_fcall_alloc+0x1e/0x90 net/9p/client.c:237 p9_tag_alloc net/9p/client.c:266 [inline] p9_client_prepare_req.part.8+0x107/0xa00 net/9p/client.c:640 p9_client_prepare_req net/9p/client.c:675 [inline] p9_client_rpc+0x242/0x1330 net/9p/client.c:675 p9_client_version net/9p/client.c:890 [inline] p9_client_create+0xca4/0x1537 net/9p/client.c:974 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135 legacy_get_tree+0x131/0x460 fs/fs_context.c:674 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1743 do_new_mount fs/namespace.c:2603 [inline] do_mount+0x6f2/0x1e20 fs/namespace.c:2927 ksys_mount+0x12d/0x140 fs/namespace.c:3143 __do_sys_mount fs/namespace.c:3157 [inline] __se_sys_mount fs/namespace.c:3154 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3154 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 4465: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xd9/0x260 mm/slab.c:3813 p9_free_req+0xb5/0x120 net/9p/client.c:338 p9_client_rpc+0xa8e/0x1330 net/9p/client.c:739 p9_client_version net/9p/client.c:890 [inline] p9_client_create+0xca4/0x1537 net/9p/client.c:974 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135 legacy_get_tree+0x131/0x460 fs/fs_context.c:674 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1743 do_new_mount fs/namespace.c:2603 [inline] do_mount+0x6f2/0x1e20 fs/namespace.c:2927 ksys_mount+0x12d/0x140 fs/namespace.c:3143 __do_sys_mount fs/namespace.c:3157 [inline] __se_sys_mount fs/namespace.c:3154 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3154 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801abd90340 which belongs to the cache kmalloc-16384 of size 16384 The buggy address is located 32 bytes inside of 16384-byte region [ffff8801abd90340, ffff8801abd94340) The buggy address belongs to the page: page:ffffea0006af6400 count:1 mapcount:0 mapping:ffff8801da802200 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0006c75e08 ffffea0006afaa08 ffff8801da802200 raw: 0000000000000000 ffff8801abd90340 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801abd90200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801abd90280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8801abd90300: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8801abd90380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801abd90400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- 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#bug-status-tracking for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches