linux-kernel - [PATCH 3.16.y-ckt 080/254] mmc: rtsx_usb_sdmmc: fix incorrect last byte in R2 response

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1416912004-5928-81-git-send-email-luis.henriques@canonical.com>
Date:	Tue, 25 Nov 2014 10:37:10 +0000
From:	Luis Henriques <luis.henriques@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Roger Tseng <rogerable@...ltek.com>,
	Ulf Hansson <ulf.hansson@...aro.org>,
	Luis Henriques <luis.henriques@...onical.com>
Subject: [PATCH 3.16.y-ckt 080/254] mmc: rtsx_usb_sdmmc: fix incorrect last byte in R2 response

3.16.7-ckt2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Roger Tseng <rogerable@...ltek.com>

commit 6f67cc6fd1cf339a0f19b9d4a998ec3c0123b1b6 upstream.

Current code erroneously fill the last byte of R2 response with an undefined
value. In addition, the controller actually 'offloads' the last byte
(CRC7, end bit) while receiving R2 response and thus it's impossible to get the
actual value. This could cause mmc stack to obtain inconsistent CID from the
same card after resume and misidentify it as a different card.

Fix by assigning dummy CRC and end bit: {7'b0, 1} = 0x1 to the last byte of R2.

Fixes: c7f6558d84af ("mmc: Add realtek USB sdmmc host driver")
Signed-off-by: Roger Tseng <rogerable@...ltek.com>
Signed-off-by: Ulf Hansson <ulf.hansson@...aro.org>
Signed-off-by: Luis Henriques <luis.henriques@...onical.com>
---
 drivers/mmc/host/rtsx_usb_sdmmc.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c
index 5d3766e792f0..d9153a7d160d 100644
--- a/drivers/mmc/host/rtsx_usb_sdmmc.c
+++ b/drivers/mmc/host/rtsx_usb_sdmmc.c
@@ -435,6 +435,13 @@ static void sd_send_cmd_get_rsp(struct rtsx_usb_sdmmc *host,
 	}
 
 	if (rsp_type == SD_RSP_TYPE_R2) {
+		/*
+		 * The controller offloads the last byte {CRC-7, end bit 1'b1}
+		 * of response type R2. Assign dummy CRC, 0, and end bit to the
+		 * byte(ptr[16], goes into the LSB of resp[3] later).
+		 */
+		ptr[16] = 1;
+
 		for (i = 0; i < 4; i++) {
 			cmd->resp[i] = get_unaligned_be32(ptr + 1 + i * 4);
 			dev_dbg(sdmmc_dev(host), "cmd->resp[%d] = 0x%08x\n",
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/