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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 5FDD9C433E4 for ; Mon, 17 Aug 2020 16:38:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2AB95207D3 for ; Mon, 17 Aug 2020 16:38:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597682330; bh=KtlD/dHbQX6e0yXtT9SBli8K4ds5ERxe2N5v+WXJC4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=azjbK/VNDxhjDMh5MUxHQDqAXAUfgwJ7CtBC22oVmPdiSZNufooC3PlJVGAkGm7Gn DeFeOwjxhmIKdS6gM8rbURy0AArppMxl0B7XSDYDR78U5BU8+i0jHMoNR6sW+ux5Ab HIP/FnDSsy9j7HLx5GF8CU0kGRYyCLAjymNf+pxg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388875AbgHQQiq (ORCPT ); Mon, 17 Aug 2020 12:38:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:44516 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388089AbgHQP4y (ORCPT ); Mon, 17 Aug 2020 11:56:54 -0400 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 E16DA207DA; Mon, 17 Aug 2020 15:56:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597679812; bh=KtlD/dHbQX6e0yXtT9SBli8K4ds5ERxe2N5v+WXJC4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nCOVb+mEbBz9gltE6Y2r/hZjvrVKxZYgsq4C/b4yJMTXw4WPpgbK3lf9MWEQaA1ZU W2s61SFYal1ea6/iIVsmQyG7ceq60m4hIP3NuYkfTAggyPH5N1NEBZTWeIvksvsP3G Ok4sARJPncV8gk5XPuKpaIinewFDOPF79yItk+zg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tom Rix , Herbert Xu Subject: [PATCH 5.7 342/393] crypto: qat - fix double free in qat_uclo_create_batch_init_list Date: Mon, 17 Aug 2020 17:16:32 +0200 Message-Id: <20200817143836.187159293@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200817143819.579311991@linuxfoundation.org> References: <20200817143819.579311991@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: Tom Rix commit c06c76602e03bde24ee69a2022a829127e504202 upstream. clang static analysis flags this error qat_uclo.c:297:3: warning: Attempt to free released memory [unix.Malloc] kfree(*init_tab_base); ^~~~~~~~~~~~~~~~~~~~~ When input *init_tab_base is null, the function allocates memory for the head of the list. When there is problem allocating other list elements the list is unwound and freed. Then a check is made if the list head was allocated and is also freed. Keeping track of the what may need to be freed is the variable 'tail_old'. The unwinding/freeing block is while (tail_old) { mem_init = tail_old->next; kfree(tail_old); tail_old = mem_init; } The problem is that the first element of tail_old is also what was allocated for the list head init_header = kzalloc(sizeof(*init_header), GFP_KERNEL); ... *init_tab_base = init_header; flag = 1; } tail_old = init_header; So *init_tab_base/init_header are freed twice. There is another problem. When the input *init_tab_base is non null the tail_old is calculated by traveling down the list to first non null entry. tail_old = init_header; while (tail_old->next) tail_old = tail_old->next; When the unwinding free happens, the last entry of the input list will be freed. So the freeing needs a general changed. If locally allocated the first element of tail_old is freed, else it is skipped. As a bit of cleanup, reset *init_tab_base if it came in as null. Fixes: b4b7e67c917f ("crypto: qat - Intel(R) QAT ucode part of fw loader") Cc: Signed-off-by: Tom Rix Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- drivers/crypto/qat/qat_common/qat_uclo.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) --- a/drivers/crypto/qat/qat_common/qat_uclo.c +++ b/drivers/crypto/qat/qat_common/qat_uclo.c @@ -332,13 +332,18 @@ static int qat_uclo_create_batch_init_li } return 0; out_err: + /* Do not free the list head unless we allocated it. */ + tail_old = tail_old->next; + if (flag) { + kfree(*init_tab_base); + *init_tab_base = NULL; + } + while (tail_old) { mem_init = tail_old->next; kfree(tail_old); tail_old = mem_init; } - if (flag) - kfree(*init_tab_base); return -ENOMEM; }