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=-5.4 required=3.0 tests=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 E4308C432C0 for ; Mon, 2 Dec 2019 18:45:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA79320718 for ; Mon, 2 Dec 2019 18:45:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727917AbfLBSpJ (ORCPT ); Mon, 2 Dec 2019 13:45:09 -0500 Received: from mail-il1-f200.google.com ([209.85.166.200]:48359 "EHLO mail-il1-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727549AbfLBSpJ (ORCPT ); Mon, 2 Dec 2019 13:45:09 -0500 Received: by mail-il1-f200.google.com with SMTP id 4so469251ill.15 for ; Mon, 02 Dec 2019 10:45:08 -0800 (PST) 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=itCABTGD8qdhBDl50zMwwE7VeQ2i5Gc0+NOJZoEJkF0=; b=rUEry1nR+hvaEKWvRr7KvTSUBmCFsV69R5HjDGrJ/Lf3nIZp9xYTMnhu7gsyEZStJB 7er7LzEa6xXmv1Xt+HVW/SakAt0t3QE4uqACP+yu0Kv5ewszIm6uKpQc6BjeN+phI/Pp My5fPMRGPp8qxCUy3Ih4s8cfccJiuf8dCnvj6VuavFvuY2QuL5FJIK3RKLdYkJTnuGKh OnopKMrM6zvpPj8VvQ0d5/+tLs3LenxnMrtbZMQYr22fdcQS5PpMgXVl659fL2fI5+5I gXEpFxozXi2i0Yy5zafS/8MRrp9agGQQuB2NvtcCmzWbaEPXvponAyjeb1m44Ul3jwAL 8U0Q== X-Gm-Message-State: APjAAAV9Dc+kncSyuHUvucQPc6ChMGxfeilY2DeoGBObUYKXGLuPK9pb 7PW6R2qs1aUfc4ATruzZ8q37OxjvbnT1a0hEFfJdpcTb97iY X-Google-Smtp-Source: APXvYqwIH2+SSVQbUDLmK8P9Y83JayLZp6b4GBVssznSDKXNoVUicLrHRqAEb07CLWNmjC8DqTLUFG4uRqm0DT2C93n7ioURFCvt MIME-Version: 1.0 X-Received: by 2002:a02:40ca:: with SMTP id n193mr1028204jaa.71.1575312308038; Mon, 02 Dec 2019 10:45:08 -0800 (PST) Date: Mon, 02 Dec 2019 10:45:08 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000880dcc0598bcfac9@google.com> Subject: possible deadlock in process_measurement (2) From: syzbot To: dmitry.kasatkin@gmail.com, jmorris@namei.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, serge@hallyn.com, syzkaller-bugs@googlegroups.com, zohar@linux.ibm.com 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: 81b6b964 Merge branch 'master' of git://git.kernel.org/pub.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17019696e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=333b76551307b2a0 dashboard link: https://syzkaller.appspot.com/bug?extid=18a1619cceea30ed45af compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+18a1619cceea30ed45af@syzkaller.appspotmail.com ====================================================== WARNING: possible circular locking dependency detected 5.4.0-syzkaller #0 Not tainted ------------------------------------------------------ syz-executor.2/596 is trying to acquire lock: ffff88802b0761a0 (&ovl_i_mutex_key[depth]){+.+.}, at: inode_lock include/linux/fs.h:791 [inline] ffff88802b0761a0 (&ovl_i_mutex_key[depth]){+.+.}, at: process_measurement+0x6f4/0x1810 security/integrity/ima/ima_main.c:230 but task is already holding lock: ffff8880547b07d0 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1409 [inline] ffff8880547b07d0 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x376/0x22b0 fs/exec.c:1754 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&sig->cred_guard_mutex){+.+.}: __mutex_lock_common kernel/locking/mutex.c:959 [inline] __mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1106 mutex_lock_killable_nested+0x16/0x20 kernel/locking/mutex.c:1136 lock_trace+0x4a/0xe0 fs/proc/base.c:406 proc_pid_personality+0x1c/0xd0 fs/proc/base.c:2961 proc_single_show+0xfd/0x1c0 fs/proc/base.c:756 seq_read+0x4ca/0x1110 fs/seq_file.c:229 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x4a4/0x660 fs/read_write.c:935 vfs_readv+0xf0/0x160 fs/read_write.c:997 do_preadv+0x1c4/0x280 fs/read_write.c:1089 __do_sys_preadv fs/read_write.c:1139 [inline] __se_sys_preadv fs/read_write.c:1134 [inline] __x64_sys_preadv+0x9a/0xf0 fs/read_write.c:1134 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #2 (&p->lock){+.+.}: __mutex_lock_common kernel/locking/mutex.c:959 [inline] __mutex_lock+0x156/0x13c0 kernel/locking/mutex.c:1106 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1121 seq_read+0x71/0x1110 fs/seq_file.c:161 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x4a4/0x660 fs/read_write.c:935 vfs_readv+0xf0/0x160 fs/read_write.c:997 kernel_readv fs/splice.c:359 [inline] default_file_splice_read+0x482/0x980 fs/splice.c:414 do_splice_to+0x127/0x180 fs/splice.c:877 splice_direct_to_actor+0x2d2/0x970 fs/splice.c:954 do_splice_direct+0x1da/0x2a0 fs/splice.c:1063 do_sendfile+0x597/0xd00 fs/read_write.c:1464 __do_sys_sendfile64 fs/read_write.c:1525 [inline] __se_sys_sendfile64 fs/read_write.c:1511 [inline] __x64_sys_sendfile64+0x1dd/0x220 fs/read_write.c:1511 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (sb_writers#3){.+.+}: percpu_down_read include/linux/percpu-rwsem.h:40 [inline] __sb_start_write+0x241/0x460 fs/super.c:1672 sb_start_write include/linux/fs.h:1650 [inline] mnt_want_write+0x3f/0xc0 fs/namespace.c:354 ovl_want_write+0x76/0xa0 fs/overlayfs/util.c:21 ovl_setattr+0xdd/0x8b0 fs/overlayfs/inode.c:27 notify_change+0xad7/0xfb0 fs/attr.c:337 do_truncate+0x158/0x220 fs/open.c:64 handle_truncate fs/namei.c:2998 [inline] do_last fs/namei.c:3414 [inline] path_openat+0x2d63/0x46d0 fs/namei.c:3525 do_filp_open+0x1a1/0x280 fs/namei.c:3555 do_sys_open+0x3fe/0x5d0 fs/open.c:1097 ksys_open include/linux/syscalls.h:1385 [inline] __do_sys_creat fs/open.c:1155 [inline] __se_sys_creat fs/open.c:1153 [inline] __x64_sys_creat+0x61/0x80 fs/open.c:1153 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #0 (&ovl_i_mutex_key[depth]){+.+.}: check_prev_add kernel/locking/lockdep.c:2476 [inline] check_prevs_add kernel/locking/lockdep.c:2581 [inline] validate_chain kernel/locking/lockdep.c:2971 [inline] __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3955 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 down_write+0x93/0x150 kernel/locking/rwsem.c:1534 inode_lock include/linux/fs.h:791 [inline] process_measurement+0x6f4/0x1810 security/integrity/ima/ima_main.c:230 ima_file_check+0xc5/0x110 security/integrity/ima/ima_main.c:438 do_last fs/namei.c:3412 [inline] path_openat+0x113d/0x46d0 fs/namei.c:3525 do_filp_open+0x1a1/0x280 fs/namei.c:3555 do_open_execat+0x137/0x690 fs/exec.c:857 __do_execve_file.isra.0+0x1702/0x22b0 fs/exec.c:1762 do_execveat_common fs/exec.c:1868 [inline] do_execve fs/exec.c:1885 [inline] __do_sys_execve fs/exec.c:1961 [inline] __se_sys_execve fs/exec.c:1956 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1956 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe other info that might help us debug this: Chain exists of: &ovl_i_mutex_key[depth] --> &p->lock --> &sig->cred_guard_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&sig->cred_guard_mutex); lock(&p->lock); lock(&sig->cred_guard_mutex); lock(&ovl_i_mutex_key[depth]); *** DEADLOCK *** 1 lock held by syz-executor.2/596: #0: ffff8880547b07d0 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds fs/exec.c:1409 [inline] #0: ffff8880547b07d0 (&sig->cred_guard_mutex){+.+.}, at: __do_execve_file.isra.0+0x376/0x22b0 fs/exec.c:1754 stack backtrace: CPU: 1 PID: 596 Comm: syz-executor.2 Not tainted 5.4.0-syzkaller #0 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+0x197/0x210 lib/dump_stack.c:118 print_circular_bug.isra.0.cold+0x163/0x172 kernel/locking/lockdep.c:1685 check_noncircular+0x32e/0x3e0 kernel/locking/lockdep.c:1809 check_prev_add kernel/locking/lockdep.c:2476 [inline] check_prevs_add kernel/locking/lockdep.c:2581 [inline] validate_chain kernel/locking/lockdep.c:2971 [inline] __lock_acquire+0x2596/0x4a00 kernel/locking/lockdep.c:3955 lock_acquire+0x190/0x410 kernel/locking/lockdep.c:4485 down_write+0x93/0x150 kernel/locking/rwsem.c:1534 inode_lock include/linux/fs.h:791 [inline] process_measurement+0x6f4/0x1810 security/integrity/ima/ima_main.c:230 ima_file_check+0xc5/0x110 security/integrity/ima/ima_main.c:438 do_last fs/namei.c:3412 [inline] path_openat+0x113d/0x46d0 fs/namei.c:3525 do_filp_open+0x1a1/0x280 fs/namei.c:3555 do_open_execat+0x137/0x690 fs/exec.c:857 __do_execve_file.isra.0+0x1702/0x22b0 fs/exec.c:1762 do_execveat_common fs/exec.c:1868 [inline] do_execve fs/exec.c:1885 [inline] __do_sys_execve fs/exec.c:1961 [inline] __se_sys_execve fs/exec.c:1956 [inline] __x64_sys_execve+0x8f/0xc0 fs/exec.c:1956 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a679 Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffbf4072c78 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000040 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffbf40736d4 R13: 00000000004c0fcd R14: 00000000004d41f0 R15: 00000000ffffffff --- 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.