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=-5.7 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=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 D7CAEC28CC5 for ; Wed, 5 Jun 2019 18:42:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AA88020872 for ; Wed, 5 Jun 2019 18:42:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726541AbfFESmI (ORCPT ); Wed, 5 Jun 2019 14:42:08 -0400 Received: from mail-it1-f199.google.com ([209.85.166.199]:56864 "EHLO mail-it1-f199.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with 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1.0 X-Received: by 2002:a02:c80d:: with SMTP id p13mr1552204jao.59.1559760127080; Wed, 05 Jun 2019 11:42:07 -0700 (PDT) Date: Wed, 05 Jun 2019 11:42:07 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000004f43fa058a97f4d3@google.com> Subject: KASAN: use-after-free Read in tomoyo_realpath_from_path From: syzbot To: jmorris@namei.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, penguin-kernel@I-love.SAKURA.ne.jp, serge@hallyn.com, syzkaller-bugs@googlegroups.com, takedakn@nttdata.co.jp Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: Hello, syzbot found the following crash on: HEAD commit: 788a0249 Merge tag 'arc-5.2-rc4' of git://git.kernel.org/p.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=179848d4a00000 kernel config: https://syzkaller.appspot.com/x/.config?x=60564cb52ab29d5b dashboard link: https://syzkaller.appspot.com/bug?extid=0341f6a4d729d4e0acf1 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13ac35baa00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+0341f6a4d729d4e0acf1@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in tomoyo_get_socket_name security/tomoyo/realpath.c:238 [inline] BUG: KASAN: use-after-free in tomoyo_realpath_from_path+0x722/0x7a0 security/tomoyo/realpath.c:284 Read of size 2 at addr ffff8880a91276d0 by task syz-executor.3/17397 CPU: 0 PID: 17397 Comm: syz-executor.3 Not tainted 5.2.0-rc3+ #12 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+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:188 __kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317 kasan_report+0x12/0x20 mm/kasan/common.c:614 __asan_report_load2_noabort+0x14/0x20 mm/kasan/generic_report.c:130 tomoyo_get_socket_name security/tomoyo/realpath.c:238 [inline] tomoyo_realpath_from_path+0x722/0x7a0 security/tomoyo/realpath.c:284 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_check_open_permission+0x2a8/0x3f0 security/tomoyo/file.c:771 tomoyo_file_open security/tomoyo/tomoyo.c:319 [inline] tomoyo_file_open+0xa9/0xd0 security/tomoyo/tomoyo.c:314 security_file_open+0x71/0x300 security/security.c:1454 do_dentry_open+0x373/0x1250 fs/open.c:765 vfs_open+0xa0/0xd0 fs/open.c:887 do_last fs/namei.c:3416 [inline] path_openat+0x10e9/0x46d0 fs/namei.c:3533 do_filp_open+0x1a1/0x280 fs/namei.c:3563 do_sys_open+0x3fe/0x5d0 fs/open.c:1070 __do_sys_open fs/open.c:1088 [inline] __se_sys_open fs/open.c:1083 [inline] __x64_sys_open+0x7e/0xc0 fs/open.c:1083 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413161 Code: 75 14 b8 02 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 19 00 00 c3 48 83 ec 08 e8 0a fa ff ff 48 89 04 24 b8 02 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007f65230f8bb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000002 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000413161 RDX: fffffffffffffffa RSI: 0000000000000000 RDI: 00007f65230f8bd0 RBP: 000000000075c060 R08: 0000000000000050 R09: 000000000000000f R10: 0000000000000004 R11: 0000000000000293 R12: 00007f65230f96d4 R13: 00000000004c83f6 R14: 00000000004dea40 R15: 00000000ffffffff Allocated by task 17373: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_kmalloc mm/kasan/common.c:489 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:462 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:503 __do_kmalloc mm/slab.c:3660 [inline] __kmalloc+0x15c/0x740 mm/slab.c:3669 kmalloc include/linux/slab.h:552 [inline] sk_prot_alloc+0x19c/0x2e0 net/core/sock.c:1602 sk_alloc+0x39/0xf70 net/core/sock.c:1656 base_sock_create drivers/isdn/mISDN/socket.c:758 [inline] mISDN_sock_create+0xb4/0x3a0 drivers/isdn/mISDN/socket.c:780 __sock_create+0x3d8/0x730 net/socket.c:1424 sock_create net/socket.c:1475 [inline] __sys_socket+0x103/0x220 net/socket.c:1517 __do_sys_socket net/socket.c:1526 [inline] __se_sys_socket net/socket.c:1524 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1524 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 17371: save_stack+0x23/0x90 mm/kasan/common.c:71 set_track mm/kasan/common.c:79 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:451 kasan_slab_free+0xe/0x10 mm/kasan/common.c:459 __cache_free mm/slab.c:3432 [inline] kfree+0xcf/0x220 mm/slab.c:3755 sk_prot_free net/core/sock.c:1639 [inline] __sk_destruct+0x4f7/0x6e0 net/core/sock.c:1725 sk_destruct+0x7b/0x90 net/core/sock.c:1733 __sk_free+0xce/0x300 net/core/sock.c:1744 sk_free+0x42/0x50 net/core/sock.c:1755 sock_put include/net/sock.h:1723 [inline] base_sock_release+0x269/0x279 drivers/isdn/mISDN/socket.c:628 __sock_release+0xce/0x2a0 net/socket.c:601 sock_close+0x1b/0x30 net/socket.c:1273 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:185 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:168 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8880a91276c0 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 16 bytes inside of 2048-byte region [ffff8880a91276c0, ffff8880a9127ec0) The buggy address belongs to the page: page:ffffea0002a44980 refcount:1 mapcount:0 mapping:ffff8880aa400c40 index:0x0 compound_mapcount: 0 flags: 0x1fffc0000010200(slab|head) raw: 01fffc0000010200 ffffea00022c9f88 ffffea0002234408 ffff8880aa400c40 raw: 0000000000000000 ffff8880a91265c0 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a9127580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a9127600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff8880a9127680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ^ ffff8880a9127700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880a9127780: 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#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches