From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3BBB0342C80; Thu, 16 Jul 2026 01:59:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=60.244.123.138 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784167178; cv=none; b=nWggh6AxdwkON1V6bmbZD/vYPOOOnfbUwBILaiZ6Ft4YYKxXLcx2BWqW0QB0kcb6wIttOrmkp9b+gMNXJ9OOCdnIijAGa1UtKNeJV+rAB4yvxAYxjdKFi8jCtd8c2AstwhwhXwsOxYf7SwXahR0Ca4MFG/T8r2mGG0d0L74gvDU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784167178; c=relaxed/simple; bh=8mEEu0fofAd3LjQpobHKIIP/WCU/gXmoGNsGVUQipTA=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=bpAJIyEl35BYmCAdl/lJcImnJWRZliivFdc/6bBmuT51qHSf9Hj9ImzGu2a46msghaZeilKwNIfu1O3Xlh/jeJvSD3lkxbfuW99NMCeNL1UaIDXX5WSg3JcWIn5qo3nz4Mf9QX2EFMKX2lZPphmloW5GG9BxcIhAs1XdAGvQ0K8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com; spf=pass smtp.mailfrom=mediatek.com; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b=Xf/9GvgJ; arc=none smtp.client-ip=60.244.123.138 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mediatek.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="Xf/9GvgJ" X-UUID: f6806d2a80b911f1b1788b6acf885367-20260716 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=AorHqhtqwV15STsrkbRcHwPgCy7RSx0CoHKVd3m/ihM=; b=Xf/9GvgJbgajWOwws1Qg9NZzNHVBzlB/GkQmAn14AWewzS4yK2fTO7408d0aO9dMNaJfIlm0Suyc5q7mMtR2B0Fezo8v4dnPD4xrVzSl5SH7Jm0aJv4DR0TbjaMsgefG+08RyFAv4y8+G3h+AHwXpDjsY5EbhB3hqXknEPfdUWc=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.3.17,REQID:88e70b68-e863-4cf0-bc3e-0fa672a3953a,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:d497b38,CLOUDID:2e302d19-ab14-4403-9336-76696324c5a8,B ulkID:nil,BulkQuantity:0,SF:81|82|102|836|865|888|898,TC:-5,Content:0|15|5 0|99|200|213,EDM:-3,IP:nil,URL:0,File:130,RT:0,Bulk:nil,QS:nil,BEC:-1,COL: 0,OSI:0,OSA:0,AV:0,LES:1,SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0,ARC:0 X-CID-BVR: 2,SSN|SDN X-CID-BAS: 2,SSN|SDN,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR X-CID-RHF: D41D8CD98F00B204E9800998ECF8427E X-UUID: f6806d2a80b911f1b1788b6acf885367-20260716 Received: from mtkmbs14n1.mediatek.inc [(172.21.101.75)] by mailgw01.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 1510600586; Thu, 16 Jul 2026 09:59:21 +0800 Received: from mtkmbs13n1.mediatek.inc (172.21.101.193) by MTKMBS14N2.mediatek.inc (172.21.101.76) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.29; Thu, 16 Jul 2026 09:59:21 +0800 Received: from mtksitap99.mediatek.inc (10.233.130.16) by mtkmbs13n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.2562.29 via Frontend Transport; Thu, 16 Jul 2026 09:59:21 +0800 From: Chris Lu To: Marcel Holtmann , Johan Hedberg , Luiz Von Dentz CC: Sean Wang , Will Lee , SS Wu , Steve Lee , Paul Menzel , linux-bluetooth , linux-kernel , linux-mediatek , Chris Lu Subject: [PATCH v12 1/7] Bluetooth: btmtksdio: Fix DMA out-of-bounds access in TX path Date: Thu, 16 Jul 2026 09:59:13 +0800 Message-ID: <20260716015920.1886719-2-chris.lu@mediatek.com> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20260716015920.1886719-1-chris.lu@mediatek.com> References: <20260716015920.1886719-1-chris.lu@mediatek.com> Precedence: bulk X-Mailing-List: linux-bluetooth@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain btmtksdio_tx_packet() aligns transfer size to 256 bytes using round_up(), but does not ensure the skb buffer has sufficient space, causing DMA to read beyond the buffer. Fix by expanding skb tailroom if needed and zero-filling the padding. Fixes: 9aebfd4a2200 ("Bluetooth: mediatek: add support for MediaTek MT7663S and MT7668S SDIO devices") Signed-off-by: Chris Lu --- drivers/bluetooth/btmtksdio.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/drivers/bluetooth/btmtksdio.c b/drivers/bluetooth/btmtksdio.c index 5b0fab7b89b5..feda1ea8f256 100644 --- a/drivers/bluetooth/btmtksdio.c +++ b/drivers/bluetooth/btmtksdio.c @@ -272,6 +272,7 @@ static int btmtksdio_tx_packet(struct btmtksdio_dev *bdev, struct sk_buff *skb) { struct mtkbtsdio_hdr *sdio_hdr; + unsigned int padded_len, pad_len; int err; /* Make sure that there are enough rooms for SDIO header */ @@ -290,18 +291,42 @@ static int btmtksdio_tx_packet(struct btmtksdio_dev *bdev, sdio_hdr->reserved = cpu_to_le16(0); sdio_hdr->bt_type = hci_skb_pkt_type(skb); + /* Calculate padded length for block-aligned DMA transfer. + * SDIO requires transfers to be block-aligned (MTK_SDIO_BLOCK_SIZE). + * Pad with zeros to prevent DMA from reading beyond skb buffer. + */ + padded_len = round_up(skb->len, MTK_SDIO_BLOCK_SIZE); + pad_len = padded_len - skb->len; + + if (pad_len > 0) { + /* Ensure sufficient tailroom for padding */ + if (unlikely(skb_tailroom(skb) < pad_len)) { + err = pskb_expand_head(skb, 0, pad_len, GFP_ATOMIC); + if (err < 0) + goto err_skb_pull; + /* Reassign sdio_hdr after buffer reallocation */ + sdio_hdr = (void *)skb->data; + } + + /* Zero-fill padding to prevent information disclosure */ + skb_put_zero(skb, pad_len); + } + clear_bit(BTMTKSDIO_HW_TX_READY, &bdev->tx_state); - err = sdio_writesb(bdev->func, MTK_REG_CTDR, skb->data, - round_up(skb->len, MTK_SDIO_BLOCK_SIZE)); + err = sdio_writesb(bdev->func, MTK_REG_CTDR, skb->data, padded_len); if (err < 0) - goto err_skb_pull; + goto err_skb_trim; - bdev->hdev->stat.byte_tx += skb->len; + /* Record actual transmitted data (excluding padding) */ + bdev->hdev->stat.byte_tx += le16_to_cpu(sdio_hdr->len); kfree_skb(skb); return 0; +err_skb_trim: + if (pad_len > 0) + skb_trim(skb, skb->len - pad_len); err_skb_pull: skb_pull(skb, sizeof(*sdio_hdr)); -- 2.45.2