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=-13.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED,USER_IN_DEF_DKIM_WL 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 404F9C04EB8 for ; Thu, 6 Dec 2018 08:40:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE03A2146D for ; Thu, 6 Dec 2018 08:40:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="K0hZLrJr" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE03A2146D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.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 S1728992AbeLFIkL (ORCPT ); Thu, 6 Dec 2018 03:40:11 -0500 Received: from mail-it1-f193.google.com ([209.85.166.193]:54739 "EHLO mail-it1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727832AbeLFIkL (ORCPT ); Thu, 6 Dec 2018 03:40:11 -0500 Received: by mail-it1-f193.google.com with SMTP id i145so107356ita.4 for ; Thu, 06 Dec 2018 00:40:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RmJuDqle0NJZjskUi5A0LUTcAvYadgzmzFEXbgK3TiY=; b=K0hZLrJrjaFRHeftkaXb3dCA5XUW47BAFC/UAFzTxdGaUTE0jrPL1DyWMkAGJ/I2jo tSoY8OtsX9XviIxaiuc7oRQXEblPp+B/2iUQxOh13VZmBP/biH4nPpTHg9FnyJnUMQNC HQll5q3/vQXYmSBn+ESsvK48CCzmA/vMMMAqaPGx4ZCt2qB3aZ5R7wrvM+THUwh8+mpW 1D/xdKg3dWapMder3sGxpqXj1kt8m+Xnk2337g6JREmpMFLIZujsfXOe/rZ4ApIIkprF VD0BAnUm883nY47O/vO/ZdX5mxo+i91jMyXaL5vUNYNnd9jiMiCrrwqLvu8cNl/jKw9m Je4w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RmJuDqle0NJZjskUi5A0LUTcAvYadgzmzFEXbgK3TiY=; b=fBx5a5E7T5tWJ0qAtl3J72FrrCQeqj/+4PgSYZuvIpGIP14HZgjWHLXt4554egMJQy emk7IaMwSF9UDF5w3WKDEGw/85ak/CbQY/sZUzgcIaI0FTfUgeAPczwIFDhLl0SvH0bv 8v52jZke4diMJQQhUzB0QUj2vTdCh6n/V5UCoNeezxvgCMfc/rt7unWAU4Wl0tTdRMvB Oe9aRHs//H9HLw0DUk0ELGyxu43n3muIgIXrwl8QOBVwGsgZPBj35bfoJGqiJC4eO40H +ELfuYNPP3Nr2ffshB4nEYK80wKlhtFtyT1cqz9RetRGNLbh71FccTH/CdE7sGOBkxSO fmLA== X-Gm-Message-State: AA+aEWaSqcbHE81Z66QcokZjWRgWqx0LQU5htSyOPCa32/eG2PsxNHM+ l8ZVnguRLcYyH2gYsgzm6FMS+5+mkM6tNnp9Hhc9xA== X-Google-Smtp-Source: AFSGD/WzQAX7VZcKMzHy0BvBShHVAkXS+ctzmYKLkaw7wJU18WQcHEwz25jGWId9iBfkKq06fu63vqBCS+NwygOjlHs= X-Received: by 2002:a24:b20e:: with SMTP id u14mr18251522ite.12.1544085609594; Thu, 06 Dec 2018 00:40:09 -0800 (PST) MIME-Version: 1.0 References: <000000000000b98a67057ad7158a@google.com> <0000000000002f45c5057c4a990d@google.com> In-Reply-To: From: Dmitry Vyukov Date: Thu, 6 Dec 2018 09:39:58 +0100 Message-ID: Subject: Re: KASAN: use-after-free Read in __lock_sock To: Xin Long Cc: syzbot+9276d76e83e3bcde6c99@syzkaller.appspotmail.com, David Miller , LKML , linux-sctp@vger.kernel.org, Marcelo Ricardo Leitner , netdev , Neil Horman , syzkaller-bugs , Vladislav Yasevich , Alexander Potapenko Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 6, 2018 at 8:21 AM Xin Long wrote: > > On Thu, Dec 6, 2018 at 3:32 AM syzbot > wrote: > > > > syzbot has found a reproducer for the following crash on: > > > > HEAD commit: 0072a0c14d5b Merge tag 'media/v4.20-4' of git://git.kernel.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=16abfdeb400000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=b9cc5a440391cbfd > How did you build the kernel with CONFIG_KMSAN? > It showed this error in my env: > scripts/Makefile.kmsan:8: Cannot use CONFIG_KMSAN: > -fsanitize=kernel-memory is not supported by compiler. > > My gcc version is: gcc (GCC) 7.1.0 Just to make sure: this bug is not detected with KMSAN and the config does not include KMSAN. You can find KMSAN instructions here: https://github.com/google/kmsan/ And you can download a prebuilt clang from here: https://github.com/google/syzkaller/blob/master/docs/syzbot.md#crash-does-not-reproduce > > dashboard link: https://syzkaller.appspot.com/bug?extid=9276d76e83e3bcde6c99 > > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12b80cfb400000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+9276d76e83e3bcde6c99@syzkaller.appspotmail.com > > > > 8021q: adding VLAN 0 to HW filter on device team0 > > 8021q: adding VLAN 0 to HW filter on device team0 > > audit: type=1400 audit(1544033924.799:39): avc: denied { associate } for > > pid=6234 comm="syz-executor3" name="syz3" > > scontext=unconfined_u:object_r:unlabeled_t:s0 > > tcontext=system_u:object_r:unlabeled_t:s0 tclass=filesystem permissive=1 > > hrtimer: interrupt took 36373 ns > > ================================================================== > > BUG: KASAN: use-after-free in __lock_acquire+0x36d9/0x4c20 > > kernel/locking/lockdep.c:3218 > > Read of size 8 at addr ffff8881b0f54820 by task syz-executor2/7909 > > > > CPU: 0 PID: 7909 Comm: syz-executor2 Not tainted 4.20.0-rc5+ #142 > > 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+0x244/0x39d lib/dump_stack.c:113 > > print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 > > kasan_report_error mm/kasan/report.c:354 [inline] > > kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 > > __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 > > __lock_acquire+0x36d9/0x4c20 kernel/locking/lockdep.c:3218 > > lock_acquire+0x1ed/0x520 kernel/locking/lockdep.c:3844 > > __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline] > > _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:168 > > spin_lock_bh include/linux/spinlock.h:334 [inline] > > __lock_sock+0x203/0x350 net/core/sock.c:2253 > > lock_sock_nested+0xfe/0x120 net/core/sock.c:2774 > > lock_sock include/net/sock.h:1492 [inline] > > sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:324 > > sctp_for_each_transport+0x2b5/0x370 net/sctp/socket.c:5075 > > sctp_diag_dump+0x3ac/0x660 net/sctp/diag.c:527 > > __inet_diag_dump+0xa8/0x140 net/ipv4/inet_diag.c:1049 > > inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1065 > > netlink_dump+0x606/0x1080 net/netlink/af_netlink.c:2244 > > __netlink_dump_start+0x59a/0x7c0 net/netlink/af_netlink.c:2352 > > netlink_dump_start include/linux/netlink.h:216 [inline] > > inet_diag_handler_cmd+0x2ce/0x3f0 net/ipv4/inet_diag.c:1170 > > __sock_diag_cmd net/core/sock_diag.c:232 [inline] > > sock_diag_rcv_msg+0x31d/0x410 net/core/sock_diag.c:263 > > netlink_rcv_skb+0x172/0x440 net/netlink/af_netlink.c:2477 > > sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:274 > > netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline] > > netlink_unicast+0x5a5/0x760 net/netlink/af_netlink.c:1336 > > netlink_sendmsg+0xa18/0xfc0 net/netlink/af_netlink.c:1917 > > sock_sendmsg_nosec net/socket.c:621 [inline] > > sock_sendmsg+0xd5/0x120 net/socket.c:631 > > sock_write_iter+0x35e/0x5c0 net/socket.c:900 > > call_write_iter include/linux/fs.h:1857 [inline] > > do_iter_readv_writev+0x8b0/0xa80 fs/read_write.c:680 > > do_iter_write+0x185/0x5f0 fs/read_write.c:959 > > vfs_writev+0x1f1/0x360 fs/read_write.c:1004 > > do_writev+0x11a/0x310 fs/read_write.c:1039 > > __do_sys_writev fs/read_write.c:1112 [inline] > > __se_sys_writev fs/read_write.c:1109 [inline] > > __x64_sys_writev+0x75/0xb0 fs/read_write.c:1109 > > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > RIP: 0033:0x457569 > > Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 > > 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff > > ff 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 > > RSP: 002b:00007f75b80d7c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 > > RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569 > > RDX: 0000000000000001 RSI: 000000002051c000 RDI: 000000000000000a > > RBP: 000000000072c0e0 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f75b80d86d4 > > R13: 00000000004c3807 R14: 00000000004d9f50 R15: 00000000ffffffff > > > > Allocated by task 7881: > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > set_track mm/kasan/kasan.c:460 [inline] > > kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 > > kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 > > kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 > > sk_prot_alloc+0x69/0x2e0 net/core/sock.c:1463 > > sk_alloc+0x10d/0x1690 net/core/sock.c:1523 > > inet_create+0x509/0x1070 net/ipv4/af_inet.c:321 > > __sock_create+0x536/0x930 net/socket.c:1277 > > sock_create net/socket.c:1317 [inline] > > __sys_socket+0x106/0x260 net/socket.c:1347 > > __do_sys_socket net/socket.c:1356 [inline] > > __se_sys_socket net/socket.c:1354 [inline] > > __x64_sys_socket+0x73/0xb0 net/socket.c:1354 > > do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > Freed by task 7908: > > save_stack+0x43/0xd0 mm/kasan/kasan.c:448 > > set_track mm/kasan/kasan.c:460 [inline] > > __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 > > kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 > > __cache_free mm/slab.c:3498 [inline] > > kmem_cache_free+0x83/0x290 mm/slab.c:3760 > > sk_prot_free net/core/sock.c:1504 [inline] > > __sk_destruct+0x728/0xa80 net/core/sock.c:1588 > > sk_destruct+0x78/0x90 net/core/sock.c:1596 > > __sk_free+0xcf/0x300 net/core/sock.c:1607 > > sk_free+0x42/0x50 net/core/sock.c:1618 > > sock_put include/net/sock.h:1693 [inline] > > sctp_close+0x8d4/0xad0 net/sctp/socket.c:1569 > > inet_release+0x104/0x1f0 net/ipv4/af_inet.c:428 > > __sock_release+0xd7/0x250 net/socket.c:579 > > sock_close+0x19/0x20 net/socket.c:1141 > > __fput+0x385/0xa30 fs/file_table.c:278 > > ____fput+0x15/0x20 fs/file_table.c:309 > > task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 > > get_signal+0x1558/0x1980 kernel/signal.c:2347 > > do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816 > > exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162 > > prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] > > syscall_return_slowpath arch/x86/entry/common.c:268 [inline] > > do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 > > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > > > The buggy address belongs to the object at ffff8881b0f54780 > > which belongs to the cache SCTP(33:syz2) of size 1776 > > The buggy address is located 160 bytes inside of > > 1776-byte region [ffff8881b0f54780, ffff8881b0f54e70) > > The buggy address belongs to the page: > > page:ffffea0006c3d500 count:1 mapcount:0 mapping:ffff8881d9391e40 index:0x0 > > flags: 0x2fffc0000000200(slab) > > raw: 02fffc0000000200 ffffea0007310108 ffff8881cc327148 ffff8881d9391e40 > > raw: 0000000000000000 ffff8881b0f54000 0000000100000002 ffff8881c0f20580 > > page dumped because: kasan: bad access detected > > page->mem_cgroup:ffff8881c0f20580 > > > > Memory state around the buggy address: > > ffff8881b0f54700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff8881b0f54780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > > ffff8881b0f54800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > > ffff8881b0f54880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff8881b0f54900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > > > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to 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