From patchwork Wed Jul 12 13:02:19 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Chris Lu X-Patchwork-Id: 13310356 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 96F9FEB64D9 for ; Wed, 12 Jul 2023 13:03:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233482AbjGLNDu (ORCPT ); Wed, 12 Jul 2023 09:03:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39914 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233478AbjGLND2 (ORCPT ); Wed, 12 Jul 2023 09:03:28 -0400 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1BF461BFD; Wed, 12 Jul 2023 06:03:22 -0700 (PDT) X-UUID: 7815dfbe20b411ee9cb5633481061a41-20230712 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:MIME-Version:Message-ID:Date:Subject:CC:To:From; bh=G1HHJBk/sQvVbiomYqcZlgk1NLXE+A6QfL373AvC8Vo=; b=VoYwL7RMiyz/1jncyQ4wWRS+Ueq3h/g5vL9ZdvrXIWaZlD9LU+Ruge2dcgShe2lWebCsmDgGbAjwJBwh95qM+5Hi2Ql+synKKs2EPfBqklREsncTIrmhxe7XMKWmZG1heF4jHUGjmMMCdt2zn3gtihgbXZqbHbTMYFaokjR+4E8=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.28,REQID:98e51d2a-2e82-4c3c-86e0-b1f2dc874cc2,IP:0,U RL:0,TC:0,Content:0,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTION: release,TS:0 X-CID-META: VersionHash:176cd25,CLOUDID:5693270e-c22b-45ab-8a43-3004e9216b56,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:11|1,File:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1,SPR: NO,DKR:0,DKP:0 X-CID-BVR: 0,NGT X-CID-BAS: 0,NGT,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_ULN X-UUID: 7815dfbe20b411ee9cb5633481061a41-20230712 Received: from mtkmbs10n2.mediatek.inc [(172.21.101.183)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 401310188; Wed, 12 Jul 2023 21:03:17 +0800 Received: from mtkmbs11n1.mediatek.inc (172.21.101.185) by mtkmbs10n2.mediatek.inc (172.21.101.183) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Wed, 12 Jul 2023 21:03:16 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkmbs11n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Wed, 12 Jul 2023 21:03:16 +0800 From: Chris Lu To: Marcel Holtmann , Johan Hedberg , Luiz Von Dentz CC: Sean Wang , Aaron Hou , Steve Lee , linux-bluetooth , linux-kernel , linux-mediatek , Chris Lu Subject: [PATCH v4] Bluetooth: btmtk: Fix null pointer when processing coredump Date: Wed, 12 Jul 2023 21:02:19 +0800 Message-ID: <20230712130218.376-1-chris.lu@mediatek.com> X-Mailer: git-send-email 2.18.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-bluetooth@vger.kernel.org There may be a potential null pointer risk if offset value is less than 0 when doing memcmp in btmtk_process_coredump(). Check offset is valid before doing memcmp. Signed-off-by: Chris Lu Co-developed-by: Sean Wang Signed-off-by: Sean Wang --- v2: fix typo v3: fix bot checking error v4: reduce variable 'offset' declaration in v3 --- drivers/bluetooth/btmtk.c | 12 ++++++------ drivers/bluetooth/btmtk.h | 1 + 2 files changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/bluetooth/btmtk.c b/drivers/bluetooth/btmtk.c index 786f775196ae..9cc789272ab7 100644 --- a/drivers/bluetooth/btmtk.c +++ b/drivers/bluetooth/btmtk.c @@ -395,12 +395,12 @@ int btmtk_process_coredump(struct hci_dev *hdev, struct sk_buff *skb) /* Mediatek coredump data would be more than MTK_COREDUMP_NUM */ if (data->cd_info.cnt > MTK_COREDUMP_NUM && - skb->len > sizeof(MTK_COREDUMP_END) && - !memcmp((char *)&skb->data[skb->len - sizeof(MTK_COREDUMP_END)], - MTK_COREDUMP_END, sizeof(MTK_COREDUMP_END) - 1)) { - bt_dev_info(hdev, "Mediatek coredump end"); - hci_devcd_complete(hdev); - } + skb->len > MTK_COREDUMP_END_LEN) + if (!memcmp((char *)&skb->data[skb->len - MTK_COREDUMP_END_LEN], + MTK_COREDUMP_END, MTK_COREDUMP_END_LEN - 1)) { + bt_dev_info(hdev, "Mediatek coredump end"); + hci_devcd_complete(hdev); + } break; } diff --git a/drivers/bluetooth/btmtk.h b/drivers/bluetooth/btmtk.h index 68309dfe076a..56f5502baadf 100644 --- a/drivers/bluetooth/btmtk.h +++ b/drivers/bluetooth/btmtk.h @@ -24,6 +24,7 @@ #define MTK_COREDUMP_SIZE (1024 * 1000) #define MTK_COREDUMP_END "coredump end" +#define MTK_COREDUMP_END_LEN (sizeof(MTK_COREDUMP_END)) #define MTK_COREDUMP_NUM 255 enum {