From patchwork Tue Jun 8 18:25:39 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 457585 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=-18.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 021E2C48BCF for ; Tue, 8 Jun 2021 19:09:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5B8E610A1 for ; Tue, 8 Jun 2021 19:09:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236634AbhFHTLK (ORCPT ); Tue, 8 Jun 2021 15:11:10 -0400 Received: from mail.kernel.org ([198.145.29.99]:44698 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235970AbhFHTHg (ORCPT ); Tue, 8 Jun 2021 15:07:36 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id DF53761935; Tue, 8 Jun 2021 18:47:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623178035; bh=jdRzOxJhc7bDRmRfhJGpruhglj34+7u7uf+BVQ4T7+I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1lpshCsR5Y9s3SPym+pfC5U6/GcdLzdRxJrsY/DIHznTsTMQ//ZijoJ0h1TiiAsG/ QTJg0wuRTbIDswr61++XllRegdfkP6DoiwIad74fKHQQYWfPntBgMUMzQ7u51nhWeA yoUak50cMoi/wHpV7wDjqPt1j8SYNF26Cq8fgDSU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Ard Biesheuvel , Sasha Levin Subject: [PATCH 5.12 009/161] efi/libstub: prevent read overflow in find_file_option() Date: Tue, 8 Jun 2021 20:25:39 +0200 Message-Id: <20210608175945.784755801@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210608175945.476074951@linuxfoundation.org> References: <20210608175945.476074951@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter [ Upstream commit c4039b29fe9637e1135912813f830994af4c867f ] If the buffer has slashes up to the end then this will read past the end of the array. I don't anticipate that this is an issue for many people in real life, but it's the right thing to do and it makes static checkers happy. Fixes: 7a88a6227dc7 ("efi/libstub: Fix path separator regression") Signed-off-by: Dan Carpenter Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin --- drivers/firmware/efi/libstub/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/firmware/efi/libstub/file.c b/drivers/firmware/efi/libstub/file.c index 4e81c6077188..dd95f330fe6e 100644 --- a/drivers/firmware/efi/libstub/file.c +++ b/drivers/firmware/efi/libstub/file.c @@ -103,7 +103,7 @@ static int find_file_option(const efi_char16_t *cmdline, int cmdline_len, return 0; /* Skip any leading slashes */ - while (cmdline[i] == L'/' || cmdline[i] == L'\\') + while (i < cmdline_len && (cmdline[i] == L'/' || cmdline[i] == L'\\')) i++; while (--result_len > 0 && i < cmdline_len) {