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=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 99EFECA9EA0 for ; Mon, 4 Nov 2019 11:30:10 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 661A1217F4 for ; Mon, 4 Nov 2019 11:30:10 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 661A1217F4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id F0ABC6B0007; Mon, 4 Nov 2019 06:30:09 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EBAE86B0008; Mon, 4 Nov 2019 06:30:09 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DD2B96B000A; Mon, 4 Nov 2019 06:30:09 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0212.hostedemail.com [216.40.44.212]) by kanga.kvack.org (Postfix) with ESMTP id C548F6B0007 for ; Mon, 4 Nov 2019 06:30:09 -0500 (EST) Received: from smtpin21.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with SMTP id 8A222181AEF1A for ; Mon, 4 Nov 2019 11:30:09 +0000 (UTC) X-FDA: 76118376138.21.boot54_14f7bacf693e X-HE-Tag: boot54_14f7bacf693e X-Filterd-Recvd-Size: 5942 Received: from mail-il1-f199.google.com (mail-il1-f199.google.com [209.85.166.199]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Mon, 4 Nov 2019 11:30:08 +0000 (UTC) Received: by mail-il1-f199.google.com with SMTP id n84so15217197ila.12 for ; Mon, 04 Nov 2019 03:30:08 -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=PGnkPBzgn5LmUkN96S1poOO8RfhEZz6HijmQ5U4KxFw=; b=gmDbSVieczqBnKwPRFIxiHQq+3IumHWFl7XUvGih7lCS+3Lt1uTaEOcL5C7vK2OhbI ma88U/uDDocjyegHfZoeU690rzRBPNkRvGKwJKcn/oy+HTrLhGtsgPXsVNcjc9k169T6 EQeSrQ07nzzjhmfDTY7vkM4C3D+Xy7kVgMcIow4zBbAfRWntVRhsjJ0G/vgKQmMbVtN6 Xh/bC2dX1jzBz4tUTfsQcZx1vZwWaairfrxuOMTjgAuMDyH3jwDwd85tpbwy/lDvWSPA XZc9cSdCPOAQ2LxbMBfZt+Nrej/LPYxnUgMSPNwZp/NCDkAxV9+D0PyGqIKTrg/ddtYJ JbRA== X-Gm-Message-State: APjAAAXrbqLOs8+3omr67pvGbcF6IXuWX7hWlKW993T2TMym5NoL/FpL PLiRWgyU+k6in7/hBEo/TBRGBidsVBCuJMYmYChfYU5eW7lp X-Google-Smtp-Source: APXvYqzu8uQP43ZnaMlWwe2TwTKUyzfmUm24k/yeAUsm4lu6yL/sgmawV98ygiq6sXibrPclby0QzvtGx8vRB2vV3rBBofsWprCB MIME-Version: 1.0 X-Received: by 2002:a92:d80e:: with SMTP id y14mr888463ilm.267.1572867007375; Mon, 04 Nov 2019 03:30:07 -0800 (PST) Date: Mon, 04 Nov 2019 03:30:07 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <000000000000411e4b059683a39c@google.com> Subject: KCSAN: data-race in __rcu_read_unlock / sync_rcu_exp_select_cpus From: syzbot To: akpm@linux-foundation.org, amir73il@gmail.com, darrick.wong@oracle.com, elver@google.com, hannes@cmpxchg.org, jack@suse.cz, josef@toxicpanda.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, songliubraving@fb.com, syzkaller-bugs@googlegroups.com, willy@infradead.org Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Hello, syzbot found the following crash on: HEAD commit: 05f22368 x86, kcsan: Enable KCSAN for x86 git tree: https://github.com/google/ktsan.git kcsan console output: https://syzkaller.appspot.com/x/log.txt?x=1296ff50e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=87d111955f40591f dashboard link: https://syzkaller.appspot.com/bug?extid=99f4ddade3c22ab0cf23 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+99f4ddade3c22ab0cf23@syzkaller.appspotmail.com ================================================================== BUG: KCSAN: data-race in __rcu_read_unlock / sync_rcu_exp_select_cpus read to 0xffffffff85a7d440 of 8 bytes by task 7624 on cpu 0: rcu_read_unlock_special kernel/rcu/tree_plugin.h:615 [inline] __rcu_read_unlock+0x381/0x3c0 kernel/rcu/tree_plugin.h:383 rcu_read_unlock include/linux/rcupdate.h:652 [inline] filemap_map_pages+0x5b3/0x990 mm/filemap.c:2687 do_fault_around mm/memory.c:3450 [inline] do_read_fault mm/memory.c:3484 [inline] do_fault mm/memory.c:3618 [inline] handle_pte_fault mm/memory.c:3849 [inline] __handle_mm_fault+0x2554/0x2cb0 mm/memory.c:3973 handle_mm_fault+0x21b/0x530 mm/memory.c:4010 do_user_addr_fault arch/x86/mm/fault.c:1441 [inline] __do_page_fault+0x3fb/0x9e0 arch/x86/mm/fault.c:1506 do_page_fault+0x54/0x233 arch/x86/mm/fault.c:1530 page_fault+0x34/0x40 arch/x86/entry/entry_64.S:1202 write to 0xffffffff85a7d440 of 8 bytes by task 7353 on cpu 1: sync_exp_reset_tree kernel/rcu/tree_exp.h:137 [inline] sync_rcu_exp_select_cpus+0xd5/0x590 kernel/rcu/tree_exp.h:427 rcu_exp_sel_wait_wake kernel/rcu/tree_exp.h:575 [inline] wait_rcu_exp_gp+0x25/0x40 kernel/rcu/tree_exp.h:589 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 7353 Comm: kworker/1:0 Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: rcu_gp wait_rcu_exp_gp ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 7353 Comm: kworker/1:0 Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: rcu_gp wait_rcu_exp_gp Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xf5/0x159 lib/dump_stack.c:113 panic+0x210/0x640 kernel/panic.c:221 kcsan_report.cold+0xc/0x10 kernel/kcsan/report.c:302 __kcsan_setup_watchpoint+0x32e/0x4a0 kernel/kcsan/core.c:411 __tsan_write8 kernel/kcsan/kcsan.c:36 [inline] __tsan_write8+0x32/0x40 kernel/kcsan/kcsan.c:36 sync_exp_reset_tree kernel/rcu/tree_exp.h:137 [inline] sync_rcu_exp_select_cpus+0xd5/0x590 kernel/rcu/tree_exp.h:427 rcu_exp_sel_wait_wake kernel/rcu/tree_exp.h:575 [inline] wait_rcu_exp_gp+0x25/0x40 kernel/rcu/tree_exp.h:589 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269 worker_thread+0xa0/0x800 kernel/workqueue.c:2415 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 Shutting down cpus with NMI Kernel Offset: disabled Rebooting in 86400 seconds.. --- 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.