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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A4749C4332F for ; Sun, 18 Dec 2022 16:34:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232179AbiLRQed (ORCPT ); Sun, 18 Dec 2022 11:34:33 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53834 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232147AbiLRQdX (ORCPT ); Sun, 18 Dec 2022 11:33:23 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED637DF70; Sun, 18 Dec 2022 08:12:21 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 82CFE60DCF; Sun, 18 Dec 2022 16:12:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 146CFC43396; Sun, 18 Dec 2022 16:12:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1671379940; bh=wS2CJozuBVaCyuHPiu85yFQAGc/LKO2AOVr+rCZej9Q=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MggUNE67K8/ttM60EbXvl6gO2lUckJPsfSIKUR/VD7mYIws3zzW/pplKlmai5VrY1 1CleHS6ws6jOJ3vZmfcogVIrRKCWUoBx8dVwaDgQuM7DbkTD1bInBiDry/a2BiB3Ag mF5OW7sZUT0zYSeyU2DOkxDV7Wnzi/M0rWqIOyOZhkjwpQya+bzmEgNU8S1lV4er6b 78wnjHab5kJ6Ndyuw/CXpwJOw8Z2Wmg/nkveQiUd1qdalOSPdhtwt3VySmQLinx2VT YHQA4ipAs2vKsk4iVe1LtLN6VSKn5U+EHqwZ5JDw9fcv/Vg2vWyep6KLGNR7t2TXzq pOaTXQg9QnkLg== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hawkins Jiawei , Jeff Layton , Trond Myklebust , Sasha Levin , anna@kernel.org, linux-nfs@vger.kernel.org Subject: [PATCH AUTOSEL 6.0 64/73] nfs: fix possible null-ptr-deref when parsing param Date: Sun, 18 Dec 2022 11:07:32 -0500 Message-Id: <20221218160741.927862-64-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20221218160741.927862-1-sashal@kernel.org> References: <20221218160741.927862-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Hawkins Jiawei [ Upstream commit 5559405df652008e56eee88872126fe4c451da67 ] According to commit "vfs: parse: deal with zero length string value", kernel will set the param->string to null pointer in vfs_parse_fs_string() if fs string has zero length. Yet the problem is that, nfs_fs_context_parse_param() will dereferences the param->string, without checking whether it is a null pointer, which may trigger a null-ptr-deref bug. This patch solves it by adding sanity check on param->string in nfs_fs_context_parse_param(). Signed-off-by: Hawkins Jiawei Reviewed-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/fs_context.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c index 4da701fd1424..0c330bc13ef2 100644 --- a/fs/nfs/fs_context.c +++ b/fs/nfs/fs_context.c @@ -684,6 +684,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc, return ret; break; case Opt_vers: + if (!param->string) + goto out_invalid_value; trace_nfs_mount_assign(param->key, param->string); ret = nfs_parse_version_string(fc, param->string); if (ret < 0) @@ -696,6 +698,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc, break; case Opt_proto: + if (!param->string) + goto out_invalid_value; trace_nfs_mount_assign(param->key, param->string); protofamily = AF_INET; switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) { @@ -732,6 +736,8 @@ static int nfs_fs_context_parse_param(struct fs_context *fc, break; case Opt_mountproto: + if (!param->string) + goto out_invalid_value; trace_nfs_mount_assign(param->key, param->string); mountfamily = AF_INET; switch (lookup_constant(nfs_xprt_protocol_tokens, param->string, -1)) { -- 2.35.1