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=-3.7 required=3.0 tests=BAYES_00,FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no 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 EC72AC433FE for ; Fri, 17 Sep 2021 07:30:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C523C611C0 for ; Fri, 17 Sep 2021 07:30:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240515AbhIQHbp (ORCPT ); Fri, 17 Sep 2021 03:31:45 -0400 Received: from mail-io1-f71.google.com ([209.85.166.71]:33756 "EHLO mail-io1-f71.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230393AbhIQHbn (ORCPT ); Fri, 17 Sep 2021 03:31:43 -0400 Received: by mail-io1-f71.google.com with SMTP id g2-20020a6b7602000000b005be59530196so18898361iom.0 for ; Fri, 17 Sep 2021 00:30:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:date:message-id:subject:from:to; bh=m3nRbhKCaWxS8OkQmfuFA20q5t1TuojdS6u2lz7XyIg=; b=agzkLKla5Ei1sneQPKGzcXjm3tnsLTIdtTi0mJBeVqWc5EkOkXHYZur+454Z6V2zQF BVczltIrjAkqx8UDUSKxaatCCdcQOq/H6z5Mu8pEp4vawiztIzhGW1/fNHlGU42y2R7J gPAuofk4+Zn0nz+26K84hTcYL3m8QEJadBQlKRYqXYFRgC0J8nLJl2sGcXgDe/jsrqAw GyyyBsJcJtjxfGXPOMQJBdKUX34MiaN6TOtsfodD86slN1pyO/+SbMMBKivYD4j/aRbE Ew5Zjur7yOEEleIJNlDeY7f6ebBRKRx/EszbfOxitpbbNZQfrHpy8biquhvUQxNSyM/6 VQiA== X-Gm-Message-State: AOAM533MgK4NTY2lb8qeuHwIhjF93dOrnR58UcTL5tAiHQxGrJgipSoP OpnJgOU+CXQpJ89zQxy4jzqFb2XUlVwalEk+wihPLIdADewk X-Google-Smtp-Source: ABdhPJyeZuMqnpDFXxjm6O9W9SV4ZGifaV5hgG26+z2XjKRZ6Y6MYgNglhtAC3RvKn9D6zriNGPo/kRc5mu8i4LhGAboVLFM3xQN MIME-Version: 1.0 X-Received: by 2002:a05:6638:1909:: with SMTP id p9mr7767060jal.108.1631863822026; Fri, 17 Sep 2021 00:30:22 -0700 (PDT) Date: Fri, 17 Sep 2021 00:30:22 -0700 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <0000000000006f0bec05cc2be7dc@google.com> Subject: [syzbot] BUG: soft lockup in call_usermodehelper_exec_async From: syzbot To: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, syzbot found the following issue on: HEAD commit: 8cae8cd89f05 seq_file: disallow extremely large seq buffer.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=135dbd12300000 kernel config: https://syzkaller.appspot.com/x/.config?x=548fbb1e84c1808e dashboard link: https://syzkaller.appspot.com/bug?extid=c3963f4f025fa5dfb78b compiler: aarch64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1 userspace arch: arm Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+c3963f4f025fa5dfb78b@syzkaller.appspotmail.com watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [kworker/u4:5:21352] Modules linked in: irq event stamp: 196 hardirqs last enabled at (195): [] exit_to_kernel_mode+0x38/0x230 arch/arm64/kernel/entry-common.c:71 hardirqs last disabled at (196): [] enter_el1_irq_or_nmi+0x10/0x20 arch/arm64/kernel/entry-common.c:113 softirqs last enabled at (116): [] _stext+0x9a4/0x1050 softirqs last disabled at (51): [] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (51): [] invoke_softirq kernel/softirq.c:439 [inline] softirqs last disabled at (51): [] __irq_exit_rcu+0x470/0x520 kernel/softirq.c:636 CPU: 1 PID: 21352 Comm: kworker/u4:5 Not tainted 5.14.0-rc2-syzkaller-00001-g8cae8cd89f05 #0 Hardware name: linux,dummy-virt (DT) pstate: 00000005 (nzcv daif -PAN -UAO -TCO BTYPE=--) pc : clear_page+0x14/0x28 arch/arm64/lib/clear_page.S:23 lr : clear_highpage include/linux/highmem.h:184 [inline] lr : kernel_init_free_pages.part.0+0x6c/0x17c mm/page_alloc.c:1283 sp : ffff800018c67380 x29: ffff800018c67380 x28: 0000000000000000 x27: ffff00007fc11ec0 x26: ffff00000fe7aef8 x25: ffff600001fcf5df x24: 00000000000014b8 x23: ffff00000fe79a40 x22: fffffc0000171340 x21: ffff800015706c40 x20: dfff800000000000 x19: fffffc0000171300 x18: ffff00006aa70bc8 x17: ffff800055045000 x16: ffff800018598000 x15: ffff000010dd0600 x14: 1ffff0000318ce3a x13: 0000000000000014 x12: ffff7f800002e267 x11: 1fffff800002e266 x10: ffff7f800002e266 x9 : 0000000000000000 x8 : ffff600000b89a00 x7 : 0000000000000000 x6 : 000000000000003f x5 : 0000000000000040 x4 : 1ffff0000304db70 x3 : 1fffe00001fcf349 x2 : 0000000000000004 x1 : 0000000000000040 x0 : ffff000005c4ca40 Call trace: clear_page+0x14/0x28 arch/arm64/lib/clear_page.S:21 kernel_init_free_pages mm/page_alloc.c:1280 [inline] post_alloc_hook+0x1ac/0x25c mm/page_alloc.c:2423 prep_new_page mm/page_alloc.c:2433 [inline] get_page_from_freelist+0x1840/0x2310 mm/page_alloc.c:4166 __alloc_pages+0x1a8/0x2234 mm/page_alloc.c:5388 alloc_pages_vma+0xb4/0x4dc mm/mempolicy.c:2208 alloc_zeroed_user_highpage_movable+0x9c/0xd0 arch/arm64/mm/fault.c:939 do_anonymous_page mm/memory.c:3767 [inline] handle_pte_fault mm/memory.c:4547 [inline] __handle_mm_fault+0xcbc/0x25e4 mm/memory.c:4684 handle_mm_fault+0x1dc/0x4ec mm/memory.c:4782 faultin_page mm/gup.c:951 [inline] __get_user_pages+0x3e4/0x744 mm/gup.c:1173 __get_user_pages_locked mm/gup.c:1359 [inline] __get_user_pages_remote+0x10c/0x500 mm/gup.c:1865 get_user_pages_remote+0x28/0x40 mm/gup.c:1938 get_arg_page+0x9c/0x1bc fs/exec.c:220 copy_string_kernel+0x170/0x294 fs/exec.c:631 kernel_execve+0x1ac/0x380 fs/exec.c:1961 call_usermodehelper_exec_async+0x260/0x460 kernel/umh.c:112 ret_from_fork+0x10/0x18 arch/arm64/kernel/entry.S:782 --- This report 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 issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.