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=-9.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 C76BEC43381 for ; Thu, 28 Feb 2019 15:32:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8E0A420C01 for ; Thu, 28 Feb 2019 15:32:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551367938; bh=33XJdYPXOXpKe8qlir1XCsIXPA+I3yWBBG5d6vjhHko=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=D1mVOfoIdmwgXt1aqiVg1fW+2GKjI6tnBzP3BrMRJVwsRUrT3HxbCUq4ldtAXXmya ChMKn4dgfDMaKB70UU7YVze9h3oQrDGL11O5V2AmZBXzaiihpg0LvuGU/n535dkcgr ptB7r7+5da0qy27W2tI4R8EtnUVokkzaaV5JBIMw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389162AbfB1PcQ (ORCPT ); Thu, 28 Feb 2019 10:32:16 -0500 Received: from mail.kernel.org ([198.145.29.99]:41444 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733307AbfB1PJB (ORCPT ); Thu, 28 Feb 2019 10:09:01 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 02C36218AE; Thu, 28 Feb 2019 15:08:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1551366539; bh=33XJdYPXOXpKe8qlir1XCsIXPA+I3yWBBG5d6vjhHko=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zu5BoJrs6sJZUmXfQ2NOswgkZddMiPrqj75O4WV3/28dxNAfvapUQqtUH/uJ9UYe5 BSbDUA+xeGzB8Shkg1pIaBZPkLLIPG7fsaaCvXx9d7ZDQbMRa+E8avH1Ufaarn2iu+ 94W3No0NUdOjF+vDzN//dMiYzRgop5sacQOnAlaA= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jakub Sitnicki , Daniel Borkmann , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.20 29/81] sk_msg: Always cancel strp work before freeing the psock Date: Thu, 28 Feb 2019 10:07:21 -0500 Message-Id: <20190228150813.10256-29-sashal@kernel.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20190228150813.10256-1-sashal@kernel.org> References: <20190228150813.10256-1-sashal@kernel.org> MIME-Version: 1.0 X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jakub Sitnicki [ Upstream commit 1d79895aef18fa05789995d86d523c9b2ee58a02 ] Despite having stopped the parser, we still need to deinitialize it by calling strp_done so that it cancels its work. Otherwise the worker thread can run after we have freed the parser, and attempt to access its workqueue resulting in a use-after-free: ================================================================== BUG: KASAN: use-after-free in pwq_activate_delayed_work+0x1b/0x1d0 Read of size 8 at addr ffff888069975240 by task kworker/u2:2/93 CPU: 0 PID: 93 Comm: kworker/u2:2 Not tainted 5.0.0-rc2-00335-g28f9d1a3d4fe-dirty #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 Workqueue: (null) (kstrp) Call Trace: print_address_description+0x6e/0x2b0 ? pwq_activate_delayed_work+0x1b/0x1d0 kasan_report+0xfd/0x177 ? pwq_activate_delayed_work+0x1b/0x1d0 ? pwq_activate_delayed_work+0x1b/0x1d0 pwq_activate_delayed_work+0x1b/0x1d0 ? process_one_work+0x4aa/0x660 pwq_dec_nr_in_flight+0x9b/0x100 worker_thread+0x82/0x680 ? process_one_work+0x660/0x660 kthread+0x1b9/0x1e0 ? __kthread_create_on_node+0x250/0x250 ret_from_fork+0x1f/0x30 Allocated by task 111: sk_psock_init+0x3c/0x1b0 sock_map_link.isra.2+0x103/0x4b0 sock_map_update_common+0x94/0x270 sock_map_update_elem+0x145/0x160 __se_sys_bpf+0x152e/0x1e10 do_syscall_64+0xb2/0x3e0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 112: kfree+0x7f/0x140 process_one_work+0x40b/0x660 worker_thread+0x82/0x680 kthread+0x1b9/0x1e0 ret_from_fork+0x1f/0x30 The buggy address belongs to the object at ffff888069975180 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 192 bytes inside of 512-byte region [ffff888069975180, ffff888069975380) The buggy address belongs to the page: page:ffffea0001a65d00 count:1 mapcount:0 mapping:ffff88806d401280 index:0x0 compound_mapcount: 0 flags: 0x4000000000010200(slab|head) raw: 4000000000010200 dead000000000100 dead000000000200 ffff88806d401280 raw: 0000000000000000 00000000800c000c 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888069975100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888069975180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888069975200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888069975280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888069975300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Reported-by: Marek Majkowski Signed-off-by: Jakub Sitnicki Link: https://lore.kernel.org/netdev/CAJPywTLwgXNEZ2dZVoa=udiZmtrWJ0q5SuBW64aYs0Y1khXX3A@mail.gmail.com Acked-by: Song Liu Signed-off-by: Daniel Borkmann Signed-off-by: Sasha Levin --- net/core/skmsg.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 54d8548076306..4932861d7b882 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -545,8 +545,7 @@ static void sk_psock_destroy_deferred(struct work_struct *gc) struct sk_psock *psock = container_of(gc, struct sk_psock, gc); /* No sk_callback_lock since already detached. */ - if (psock->parser.enabled) - strp_done(&psock->parser.strp); + strp_done(&psock->parser.strp); cancel_work_sync(&psock->work); -- 2.19.1