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,URIBL_BLOCKED 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 90B31C2D0E8 for ; Fri, 3 Apr 2020 12:35:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7040020721 for ; Fri, 3 Apr 2020 12:35:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403977AbgDCMfQ (ORCPT ); Fri, 3 Apr 2020 08:35:16 -0400 Received: from mail-io1-f72.google.com ([209.85.166.72]:35684 "EHLO mail-io1-f72.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403965AbgDCMfO (ORCPT ); Fri, 3 Apr 2020 08:35:14 -0400 Received: by mail-io1-f72.google.com with SMTP id c10so5907968ioc.2 for ; Fri, 03 Apr 2020 05:35:13 -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=9i6KFf8WUAlZJA8NaxnAVF5EgcrymN6UAh6zvSpVWlU=; b=VlLULW3+MNtgQ+xQQEuGYWFGrQyPuLOm/gzkvqPi+4Z7pFj5eF/YxyYGjGM2Ka+5bO n76lto/WKiCC3c5QWNzcMwjV9dBlSCQLg2lwniHnLFR9Z++J2YphGzdeR9nthOSt9o4k aw15hd5vatsxOsNWPJIrwe1cjYgxWVb9EnvDx0VOWzgaHYXTA0OaCp3YZ7yYqAiCI6lR zgkZc3CkTwG3DLvSA2Iu9NknJ2kzosLNv4+c9oMiHMace7hiwZ3jr8rh8U5V4gZEOwdJ 8BKPu3yGRxyCE2FYMWGD94dsEWXFtTHPm5K3w9HaCiofRFPRtolix57QK0ClEx8jM3Dh 1zVw== X-Gm-Message-State: AGi0PuY5OTyji57+GTOElQgs0erxrAaTe2mV6ExhrYkpAKlKutYzNfbD sdYU6vRd4kw4sphFh43jpIh5xBivyPAkWZSQRWkBsuZbDVc3 X-Google-Smtp-Source: APiQypKXPAosbIPldoa5yp5n5oDNa/0NJcZ/JuFc+bCwocwk/C4fvhskYbi+ZTbJyJC4peWtusiAOlVC9sGWh8CnEB7ZfZ5M1JRF MIME-Version: 1.0 X-Received: by 2002:a5e:8a4d:: with SMTP id o13mr7561447iom.31.1585917312640; Fri, 03 Apr 2020 05:35:12 -0700 (PDT) Date: Fri, 03 Apr 2020 05:35:12 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000102ba005a2622624@google.com> Subject: KCSAN: data-race in binder_dec_node_nilocked / binder_state_show From: syzbot To: arve@android.com, christian@brauner.io, devel@driverdev.osuosl.org, elver@google.com, gregkh@linuxfoundation.org, joel@joelfernandes.org, linux-kernel@vger.kernel.org, maco@android.com, syzkaller-bugs@googlegroups.com, tkjos@android.com 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 Hello, syzbot found the following crash on: HEAD commit: 245a4300 Merge branch 'rcu/kcsan' into tip/locking/kcsan git tree: https://github.com/google/ktsan.git kcsan console output: https://syzkaller.appspot.com/x/log.txt?x=106b67f1e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=a4b9db179318d21f dashboard link: https://syzkaller.appspot.com/bug?extid=71f39766a98dddab97b5 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+71f39766a98dddab97b5@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in binder_dec_node_nilocked / binder_state_show write to 0xffff88809f276954 of 4 bytes by task 1408 on cpu 0: binder_state_show+0xd8/0x260 drivers/android/binder.c:5938 seq_read+0x350/0x9d0 fs/seq_file.c:229 full_proxy_read+0xbd/0x100 fs/debugfs/file.c:220 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x357/0x3d0 fs/read_write.c:935 vfs_readv+0x9c/0xf0 fs/read_write.c:997 do_preadv+0x131/0x1d0 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+0x61/0x80 fs/read_write.c:1134 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 read to 0xffff88809f276954 of 4 bytes by task 1416 on cpu 1: binder_dec_node_nilocked+0x382/0x610 drivers/android/binder.c:1261 binder_dec_node_tmpref+0xa3/0x120 drivers/android/binder.c:1379 binder_put_node drivers/android/binder.c:1387 [inline] binder_state_show+0x1aa/0x260 drivers/android/binder.c:5950 seq_read+0x350/0x9d0 fs/seq_file.c:229 full_proxy_read+0xbd/0x100 fs/debugfs/file.c:220 do_loop_readv_writev fs/read_write.c:714 [inline] do_loop_readv_writev fs/read_write.c:701 [inline] do_iter_read+0x357/0x3d0 fs/read_write.c:935 vfs_readv+0x9c/0xf0 fs/read_write.c:997 do_preadv+0x131/0x1d0 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+0x61/0x80 fs/read_write.c:1134 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1416 Comm: syz-executor.1 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ================================================================== --- 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.