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=-9.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 846CBC282CE for ; Wed, 24 Apr 2019 17:16:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56AB721905 for ; Wed, 24 Apr 2019 17:16:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126195; bh=+Sn4IrvSKhmu3fZAMwLOBwq+ken40Fc3YS78of/tdVk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=F5Zf/3yVx+ZvD+C5E0u5R7IlfVDL33KPqhkP2ZhTS93km+THxcJ7ZpyVhnRXAS+gu npwLHiIOQkEX9LV07sCD5rBCQM7L4ZBdCCt4kMStsvlXEUGkmGYaLgfatt1FGOuCnU kglOGYjXuI9CgtCA1D0wsa+PNbZOpCSmd12XilOU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388434AbfDXRQe (ORCPT ); Wed, 24 Apr 2019 13:16:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:41094 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388415AbfDXRQa (ORCPT ); Wed, 24 Apr 2019 13:16:30 -0400 Received: from localhost (62-193-50-229.as16211.net [62.193.50.229]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3671021903; Wed, 24 Apr 2019 17:16:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1556126189; bh=+Sn4IrvSKhmu3fZAMwLOBwq+ken40Fc3YS78of/tdVk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nsXJjwoqn/0nrqnHQDQXDhrZforCauGM+mvR8YIxMK7tHE+ENneKlgWtgIzshOmiu vlfXfVmZK3/+Q0NSE9oCZ9lX0TsJIbnZamzZp8j+Jg9aqvBN+W+VZfKTdk3+xBtep9 W0dsu7FZ+SPt7GyAqKTJMkOQtk7eWr7fGMFJCD7A= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Richard Zhang , Andrew Morton , Al Viro , Linus Torvalds , Sasha Levin Subject: [PATCH 4.4 022/168] fs/file.c: initialize init_files.resize_wait Date: Wed, 24 Apr 2019 19:07:46 +0200 Message-Id: <20190424170924.910645087@linuxfoundation.org> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190424170923.452349382@linuxfoundation.org> References: <20190424170923.452349382@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 5704a06810682683355624923547b41540e2801a ] (Taken from https://bugzilla.kernel.org/show_bug.cgi?id=200647) 'get_unused_fd_flags' in kthread cause kernel crash. It works fine on 4.1, but causes crash after get 64 fds. It also cause crash on ubuntu1404/1604/1804, centos7.5, and the crash messages are almost the same. The crash message on centos7.5 shows below: start fd 61 start fd 62 start fd 63 BUG: unable to handle kernel NULL pointer dereference at (null) IP: __wake_up_common+0x2e/0x90 PGD 0 Oops: 0000 [#1] SMP Modules linked in: test(OE) xt_CHECKSUM iptable_mangle ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge stp llc ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter devlink sunrpc kvm_intel kvm irqbypass crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd sg ppdev pcspkr virtio_balloon parport_pc parport i2c_piix4 joydev ip_tables xfs libcrc32c sr_mod cdrom sd_mod crc_t10dif crct10dif_generic ata_generic pata_acpi virtio_scsi virtio_console virtio_net cirrus drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops ttm crct10dif_pclmul crct10dif_common crc32c_intel drm ata_piix serio_raw libata virtio_pci virtio_ring i2c_core virtio floppy dm_mirror dm_region_hash dm_log dm_mod CPU: 2 PID: 1820 Comm: test_fd Kdump: loaded Tainted: G OE ------------ 3.10.0-862.3.3.el7.x86_64 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 task: ffff8e92b9431fa0 ti: ffff8e94247a0000 task.ti: ffff8e94247a0000 RIP: 0010:__wake_up_common+0x2e/0x90 RSP: 0018:ffff8e94247a2d18 EFLAGS: 00010086 RAX: 0000000000000000 RBX: ffffffff9d09daa0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000003 RDI: ffffffff9d09daa0 RBP: ffff8e94247a2d50 R08: 0000000000000000 R09: ffff8e92b95dfda8 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9d09daa8 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000003 FS: 0000000000000000(0000) GS:ffff8e9434e80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000017c686000 CR4: 00000000000207e0 Call Trace: __wake_up+0x39/0x50 expand_files+0x131/0x250 __alloc_fd+0x47/0x170 get_unused_fd_flags+0x30/0x40 test_fd+0x12a/0x1c0 [test] kthread+0xd1/0xe0 ret_from_fork_nospec_begin+0x21/0x21 Code: 66 90 55 48 89 e5 41 57 41 89 f7 41 56 41 89 ce 41 55 41 54 49 89 fc 49 83 c4 08 53 48 83 ec 10 48 8b 47 08 89 55 cc 4c 89 45 d0 <48> 8b 08 49 39 c4 48 8d 78 e8 4c 8d 69 e8 75 08 eb 3b 4c 89 ef RIP __wake_up_common+0x2e/0x90 RSP CR2: 0000000000000000 This issue exists since CentOS 7.5 3.10.0-862 and CentOS 7.4 (3.10.0-693.21.1 ) is ok. Root cause: the item 'resize_wait' is not initialized before being used. Reported-by: Richard Zhang Reviewed-by: Andrew Morton Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/file.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/file.c b/fs/file.c index 39f8f15921da..7e9eb65a2912 100644 --- a/fs/file.c +++ b/fs/file.c @@ -474,6 +474,7 @@ struct files_struct init_files = { .full_fds_bits = init_files.full_fds_bits_init, }, .file_lock = __SPIN_LOCK_UNLOCKED(init_files.file_lock), + .resize_wait = __WAIT_QUEUE_HEAD_INITIALIZER(init_files.resize_wait), }; static unsigned long find_next_fd(struct fdtable *fdt, unsigned long start) -- 2.19.1