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=-9.8 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,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 122F3C43603 for ; Wed, 11 Dec 2019 15:23:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CE5C0208C3 for ; Wed, 11 Dec 2019 15:23:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576077789; bh=3aXXUP6CSHv5npCS0f3X5zHZNaBwI9CZNedUZywSiRg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=wDiXkIe35Nbd611Y5SViRGyPWdySQJT1y1P2S6HGjIcNrLQgB1wsZwXLsVpkxX7Dj ind00ZfNAY1LEDLXH0PaIsRjJ8JlkHg0XaXA48kyezRAwh8nz9KH64bXDYUIlO4bGN +lSQ62cHvBjCnvkCYxHzMuxmCFlPQlQ57cuVaLZU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732676AbfLKPXI (ORCPT ); Wed, 11 Dec 2019 10:23:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:53898 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732184AbfLKPXF (ORCPT ); Wed, 11 Dec 2019 10:23:05 -0500 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 A9AD0208C3; Wed, 11 Dec 2019 15:23:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1576077784; bh=3aXXUP6CSHv5npCS0f3X5zHZNaBwI9CZNedUZywSiRg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=BmgFo2DH4Kt4jERr7/Cfv7Ynh/cFGM0g95M/+MceK3NWdebHW2koh8EeReCkYoVpR Dj1LMdJFvJg8z965uynS46zf9GoQbrVn7YRqsMcTL/isPDjGj1wbIEwwMkpQmMjRYq WzLbpKc4AERf/jEr7sVtNQDyVM/a5BCp2fXqz338= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , "Joel Fernandes (Google)" , Kees Cook , Sasha Levin Subject: [PATCH 4.19 169/243] pstore/ram: Avoid NULL deref in ftrace merging failure path Date: Wed, 11 Dec 2019 16:05:31 +0100 Message-Id: <20191211150350.589883633@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191211150339.185439726@linuxfoundation.org> References: <20191211150339.185439726@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 From: Kees Cook [ Upstream commit 8665569e97dd52920713b95675409648986b5b0d ] Given corruption in the ftrace records, it might be possible to allocate tmp_prz without assigning prz to it, but still marking it as needing to be freed, which would cause at least a NULL dereference. smatch warnings: fs/pstore/ram.c:340 ramoops_pstore_read() error: we previously assumed 'prz' could be null (see line 255) https://lists.01.org/pipermail/kbuild-all/2018-December/055528.html Reported-by: Dan Carpenter Fixes: 2fbea82bbb89 ("pstore: Merge per-CPU ftrace records into one") Cc: "Joel Fernandes (Google)" Signed-off-by: Kees Cook Signed-off-by: Sasha Levin --- fs/pstore/ram.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 015d74ee31a03..631ae057ab537 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -301,6 +301,7 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) GFP_KERNEL); if (!tmp_prz) return -ENOMEM; + prz = tmp_prz; free_prz = true; while (cxt->ftrace_read_cnt < cxt->max_ftrace_cnt) { @@ -323,7 +324,6 @@ static ssize_t ramoops_pstore_read(struct pstore_record *record) goto out; } record->id = 0; - prz = tmp_prz; } } -- 2.20.1