This is a note to let you know that I've just added the patch titled
hwmon: (amc6821) Fix possible race condition bug
to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
hwmon-amc6821-fix-possible-race-condition-bug.patch
and it can be found in the queue-3.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From cf44819c98db11163f58f08b822d626c7a8f5188 Mon Sep 17 00:00:00 2001
From: Axel Lin <axel.lin@xxxxxxxxxx>
Date: Thu, 31 Jul 2014 09:43:19 +0800
Subject: hwmon: (amc6821) Fix possible race condition bug
From: Axel Lin <axel.lin@xxxxxxxxxx>
commit cf44819c98db11163f58f08b822d626c7a8f5188 upstream.
Ensure mutex lock protects the read-modify-write period to prevent possible
race condition bug.
In additional, update data->valid should also be protected by the mutex lock.
Signed-off-by: Axel Lin <axel.lin@xxxxxxxxxx>
Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/hwmon/amc6821.c | 17 +++++++++++------
1 file changed, 11 insertions(+), 6 deletions(-)
--- a/drivers/hwmon/amc6821.c
+++ b/drivers/hwmon/amc6821.c
@@ -360,11 +360,13 @@ static ssize_t set_pwm1_enable(
if (config)
return config;
+ mutex_lock(&data->update_lock);
config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF1);
if (config < 0) {
dev_err(&client->dev,
"Error reading configuration register, aborting.\n");
- return config;
+ count = config;
+ goto unlock;
}
switch (val) {
@@ -381,14 +383,15 @@ static ssize_t set_pwm1_enable(
config |= AMC6821_CONF1_FDRC1;
break;
default:
- return -EINVAL;
+ count = -EINVAL;
+ goto unlock;
}
- mutex_lock(&data->update_lock);
if (i2c_smbus_write_byte_data(client, AMC6821_REG_CONF1, config)) {
dev_err(&client->dev,
"Configuration register write error, aborting.\n");
count = -EIO;
}
+unlock:
mutex_unlock(&data->update_lock);
return count;
}
@@ -493,8 +496,9 @@ static ssize_t set_temp_auto_point_temp(
return -EINVAL;
}
- data->valid = 0;
mutex_lock(&data->update_lock);
+ data->valid = 0;
+
switch (ix) {
case 0:
ptemp[0] = clamp_val(val / 1000, 0,
@@ -658,13 +662,14 @@ static ssize_t set_fan1_div(
if (config)
return config;
+ mutex_lock(&data->update_lock);
config = i2c_smbus_read_byte_data(client, AMC6821_REG_CONF4);
if (config < 0) {
dev_err(&client->dev,
"Error reading configuration register, aborting.\n");
- return config;
+ count = config;
+ goto EXIT;
}
- mutex_lock(&data->update_lock);
switch (val) {
case 2:
config &= ~AMC6821_CONF4_PSPR;
Patches currently in stable-queue which might be from axel.lin@xxxxxxxxxx are
queue-3.14/hwmon-sis5595-prevent-overflow-problem-when-writing-large-limits.patch
queue-3.14/hwmon-ads1015-fix-off-by-one-for-valid-channel-index-checking.patch
queue-3.14/hwmon-lm78-fix-overflow-problems-seen-when-writing-large-temperature-limits.patch
queue-3.14/hwmon-gpio-fan-prevent-overflow-problem-when-writing-large-limits.patch
queue-3.14/hwmon-amc6821-fix-possible-race-condition-bug.patch
queue-3.14/hwmon-ads1015-fix-out-of-bounds-array-access.patch
queue-3.14/hwmon-dme1737-prevent-overflow-problem-when-writing-large-limits.patch
queue-3.14/hwmon-lm85-fix-various-errors-on-attribute-writes.patch
--
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