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authorPeter Huewe <PeterHuewe@gmx.de>2013-10-30 00:54:20 +0100
committerPeter Huewe <peterhuewe@gmx.de>2014-01-06 14:37:24 +0100
commit85c5e0d451125c6ddb78663972e40af810b83644 (patch)
treef3f18600d88694e7fd9d38b8aaf810a551b53685 /drivers/char
parent238b1eaa59e6a8e2993af0db9ec2255bfa53927b (diff)
downloadlinux-linaro-stable-85c5e0d451125c6ddb78663972e40af810b83644.tar.gz
tpm/tpm_i2c_stm_st33: Check return code of get_burstcount
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 Cc: stable@vger.kernel.org Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Diffstat (limited to 'drivers/char')
-rw-r--r--drivers/char/tpm/tpm_i2c_stm_st33.c7
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/char/tpm/tpm_i2c_stm_st33.c b/drivers/char/tpm/tpm_i2c_stm_st33.c
index a0d6ceb5d005..cf6840385483 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)