From patchwork Sat Jan 11 09:49:08 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 234186 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 CDCD5C33CA4 for ; Sat, 11 Jan 2020 10:00:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A0DA32082E for ; Sat, 11 Jan 2020 10:00:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736828; bh=ymVgdOoEAFWU4jK0LXVfQteJ4Fzw/vFX8zfX+147bdE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MCypd3UI/uKgpu8jAr3dSMA4xZZWT8uuWNEyBRnTJmKWhie0T8XyN/PK54b6ER3Vq NFzsd/485SSI752qJkvzJp2VRfpjJaMfZNdz7xwQdxcRvFx7NRghcMU8ZVVJuS7uHy fmi1RwXsOoa8n7+DC8jrksMVcafOERZCehZEdbeE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729221AbgAKKA1 (ORCPT ); Sat, 11 Jan 2020 05:00:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:56590 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729185AbgAKKA0 (ORCPT ); Sat, 11 Jan 2020 05:00:26 -0500 Received: from localhost (unknown [62.119.166.9]) (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 C58662082E; Sat, 11 Jan 2020 10:00:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578736825; bh=ymVgdOoEAFWU4jK0LXVfQteJ4Fzw/vFX8zfX+147bdE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FANfavlqjckXgxNpukAy2A0NiAXaE38M6uNG8EQC+Rl269HicBV9p9sWVVvhl43My 2xuTfLBrbXVth1pI13MUTlYcWRL/WJmaOI2oiP3UTGAHQZVjHE1RQ6XZWqrEDkaWfm fDKwjAfJAVDS3OcmqRQ/BcE9sHVUVTv3S+ilI3pE= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+c732f8644185de340492@syzkaller.appspotmail.com, Brian Foster , "Darrick J. Wong" , Sasha Levin Subject: [PATCH 4.9 15/91] xfs: fix mount failure crash on invalid iclog memory access Date: Sat, 11 Jan 2020 10:49:08 +0100 Message-Id: <20200111094848.660860249@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200111094844.748507863@linuxfoundation.org> References: <20200111094844.748507863@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Brian Foster [ Upstream commit 798a9cada4694ca8d970259f216cec47e675bfd5 ] syzbot (via KASAN) reports a use-after-free in the error path of xlog_alloc_log(). Specifically, the iclog freeing loop doesn't handle the case of a fully initialized ->l_iclog linked list. Instead, it assumes that the list is partially constructed and NULL terminated. This bug manifested because there was no possible error scenario after iclog list setup when the original code was added. Subsequent code and associated error conditions were added some time later, while the original error handling code was never updated. Fix up the error loop to terminate either on a NULL iclog or reaching the end of the list. Reported-by: syzbot+c732f8644185de340492@syzkaller.appspotmail.com Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin --- fs/xfs/xfs_log.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c index 33c9a3aae948..7bfcd09d446b 100644 --- a/fs/xfs/xfs_log.c +++ b/fs/xfs/xfs_log.c @@ -1540,6 +1540,8 @@ xlog_alloc_log( if (iclog->ic_bp) xfs_buf_free(iclog->ic_bp); kmem_free(iclog); + if (prev_iclog == log->l_iclog) + break; } spinlock_destroy(&log->l_icloglock); xfs_buf_free(log->l_xbuf);