Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755763AbaBGNBf (ORCPT ); Fri, 7 Feb 2014 08:01:35 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:41787 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754629AbaBGLtj (ORCPT ); Fri, 7 Feb 2014 06:49:39 -0500 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Peter Huewe , Luis Henriques Subject: [PATCH 3.11 082/233] tpm/tpm_i2c_stm_st33: Check return code of get_burstcount Date: Fri, 7 Feb 2014 11:45:01 +0000 Message-Id: <1391773652-25214-83-git-send-email-luis.henriques@canonical.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> References: <1391773652-25214-1-git-send-email-luis.henriques@canonical.com> X-Extended-Stable: 3.11 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.11.10.4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Peter Huewe commit 85c5e0d451125c6ddb78663972e40af810b83644 upstream. The 'get_burstcount' function can in some circumstances 'return -EBUSY' which in tpm_stm_i2c_send is stored in an 'u32 burstcnt' thus converting the signed value into an unsigned value, resulting in 'burstcnt' being huge. Changing the type to u32 only does not solve the problem as the signed value is converted to an unsigned in I2C_WRITE_DATA, resulting in the same effect. Thus -> Change type of burstcnt to u32 (the return type of get_burstcount) -> Add a check for the return value of 'get_burstcount' and propagate a potential error. This makes also sense in the 'I2C_READ_DATA' case, where the there is no signed/unsigned conversion. found by coverity Signed-off-by: Peter Huewe Signed-off-by: Luis Henriques --- drivers/char/tpm/tpm_i2c_stm_st33.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/char/tpm/tpm_i2c_stm_st33.c b/drivers/char/tpm/tpm_i2c_stm_st33.c index 5bb8e2d..156bd3c 100644 --- a/drivers/char/tpm/tpm_i2c_stm_st33.c +++ b/drivers/char/tpm/tpm_i2c_stm_st33.c @@ -410,6 +410,8 @@ static int recv_data(struct tpm_chip *chip, u8 *buf, size_t count) &chip->vendor.read_queue) == 0) { burstcnt = get_burstcount(chip); + if (burstcnt < 0) + return burstcnt; len = min_t(int, burstcnt, count - size); I2C_READ_DATA(client, TPM_DATA_FIFO, buf + size, len); size += len; @@ -451,7 +453,8 @@ static irqreturn_t tpm_ioserirq_handler(int irq, void *dev_id) static int tpm_stm_i2c_send(struct tpm_chip *chip, unsigned char *buf, size_t len) { - u32 status, burstcnt = 0, i, size; + u32 status, i, size; + int burstcnt = 0; int ret; u8 data; struct i2c_client *client; @@ -482,6 +485,8 @@ static int tpm_stm_i2c_send(struct tpm_chip *chip, unsigned char *buf, for (i = 0; i < len - 1;) { burstcnt = get_burstcount(chip); + if (burstcnt < 0) + return burstcnt; size = min_t(int, len - i - 1, burstcnt); ret = I2C_WRITE_DATA(client, TPM_DATA_FIFO, buf, size); if (ret < 0) -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/