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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id x2-20020a1709027c0200b0019472226769sm2088379pll.251.2023.02.03.14.32.55 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Feb 2023 14:32:55 -0800 (PST) From: Kees Cook To: Jean Delvare Cc: Kees Cook , Guenter Roeck , linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH v2] lm85: Bounds check to_sensor_dev_attr()->index usage Date: Fri, 3 Feb 2023 22:32:53 +0000 Message-Id: <20230203223250.gonna.713-kees@kernel.org> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=15718; h=from:subject:message-id; bh=ZouD4Z3Ww372Dpxgk/0f1RnmY3+v5/1iNPuY8rOBBR0=; b=owEBbQKS/ZANAwAKAYly9N/cbcAmAcsmYgBj3YuVotP5/5IGPMz5ZgGZU/d1fLrxdNIBezFeTOB+ luULk0yJAjMEAAEKAB0WIQSlw/aPIp3WD3I+bhOJcvTf3G3AJgUCY92LlQAKCRCJcvTf3G3AJshcEA CPIy2c428GTh2P9Vz8jfq8dyIALk5aDiFb+wtNTJ6/qpEzcMWHUQ/HCJp6w88pylvgdcNQgN/ijx5y 0kJMwEQ7lhUnV469ZeVIpM/xOPlRKqRCGKOD31jARiX3/b2Jcu0XUkac6RsRSpUgH3muSt6mFsz8L7 VBG18b0i+eZznEIjUo6GVv3jp8EH/mxG43pZZPLz2DO/vY77/X1WY0IGAvTP2MYRacp6EnmT+4RvXb /KufqyPEUd7eebvLBPRjnbQRdsnUSTDEsj9ZxxzmxjfHdXefodXxo32T13/sO0eoqEKm19bGHGWR/W /DNepx1/F3+TQ3ggDB4OtZEEt12SGXRpYxgSumI1U0pEY/lA8dc9s2TyJ4Xd9kitWoAxjQ6r23tvrI pdUv1qVggA2Hz3IYnzTf5sQSLEUeuBffBaAur3km+Du+2lbuvDXYtFa5FcP1zm7qQNzIVDm7f5vfyO 5gGS8P5+0g6fbJoMzCmQt4a3gxlXCs3GHmNDXVdh3TrV4ApR+4mo1qWnS2CXjZONKIQLet0Yv+lrCO WvgRUEu90KNy/n9SWSyEsLF6gCh10buMUjHNa2XHFHwv4Lzg20Err3Z3H6/cDWzJloFEF46I8NWI31 OMrdjNLGbJjSGA1tx+xWizTxwGkeoK/vKjqVelthIq9a/W9I0oOENC9P13WQ== X-Developer-Key: i=keescook@chromium.org; a=openpgp; fpr=A5C3F68F229DD60F723E6E138972F4DFDC6DC026 Precedence: bulk List-ID: X-Mailing-List: linux-hardening@vger.kernel.org The index into various register arrays was not bounds checked. Provide a simple wrapper to bounds check the index, adding robustness in the face of memory corruption, unexpected index manipulation, etc. Noticed under GCC 13 with -Warray-bounds: drivers/hwmon/lm85.c: In function 'pwm_auto_pwm_minctl_store': drivers/hwmon/lm85.c:1110:26: warning: array subscript [0, 31] is outside array bounds of 'struct lm85_autofan[3]' [-Warray-bounds=] 1110 | if (data->autofan[nr].min_off) | ~~~~~~~~~~~~~^~~~ drivers/hwmon/lm85.c:317:29: note: while referencing 'autofan' 317 | struct lm85_autofan autofan[3]; | ^~~~~~~ Additionally fix a comment indentation and a coding style issue of a missing space before the { in the struct sensor_device_attribute definition. Cc: Jean Delvare Cc: Guenter Roeck Cc: linux-hwmon@vger.kernel.org Signed-off-by: Kees Cook --- v2: create a common helper for bounds checking v1: https://lore.kernel.org/linux-hardening/20230127223744.never.113-kees@kernel.org/ --- drivers/hwmon/lm85.c | 77 +++++++++++++++++++++---------------- include/linux/hwmon-sysfs.h | 2 +- 2 files changed, 44 insertions(+), 35 deletions(-) diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c index 8d33c2484755..3cb04e4138b8 100644 --- a/drivers/hwmon/lm85.c +++ b/drivers/hwmon/lm85.c @@ -318,6 +318,15 @@ struct lm85_data { struct lm85_zone zone[3]; }; +#define get_sensor_index(attr, array) \ +({ \ + unsigned int _nr = to_sensor_dev_attr(attr)->index; \ + \ + if (WARN_ON_ONCE(_nr >= ARRAY_SIZE(array))) \ + _nr = 0; \ + _nr; \ +}) + static int lm85_read_value(struct i2c_client *client, u8 reg) { int res; @@ -552,16 +561,16 @@ static struct lm85_data *lm85_update_device(struct device *dev) static ssize_t fan_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->fan); return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[nr])); } static ssize_t fan_min_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->fan_min); return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan_min[nr])); } @@ -569,8 +578,8 @@ static ssize_t fan_min_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->fan_min); struct i2c_client *client = data->client; unsigned long val; int err; @@ -683,16 +692,16 @@ static SENSOR_DEVICE_ATTR_RO(fan4_alarm, alarm, 13); static ssize_t pwm_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->pwm); return sprintf(buf, "%d\n", PWM_FROM_REG(data->pwm[nr])); } static ssize_t pwm_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->pwm); struct i2c_client *client = data->client; unsigned long val; int err; @@ -711,8 +720,8 @@ static ssize_t pwm_store(struct device *dev, struct device_attribute *attr, static ssize_t pwm_enable_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); int pwm_zone, enable; pwm_zone = ZONE_FROM_REG(data->autofan[nr].config); @@ -734,8 +743,8 @@ static ssize_t pwm_enable_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); struct i2c_client *client = data->client; u8 config; unsigned long val; @@ -777,8 +786,8 @@ static ssize_t pwm_enable_store(struct device *dev, static ssize_t pwm_freq_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->pwm_freq); int freq; if (IS_ADT7468_HFPWM(data)) @@ -794,8 +803,8 @@ static ssize_t pwm_freq_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->pwm_freq); struct i2c_client *client = data->client; unsigned long val; int err; @@ -843,8 +852,8 @@ static SENSOR_DEVICE_ATTR_RW(pwm3_freq, pwm_freq, 2); static ssize_t in_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->in); return sprintf(buf, "%d\n", INSEXT_FROM_REG(nr, data->in[nr], data->in_ext[nr])); } @@ -852,16 +861,16 @@ static ssize_t in_show(struct device *dev, struct device_attribute *attr, static ssize_t in_min_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->in); return sprintf(buf, "%d\n", INS_FROM_REG(nr, data->in_min[nr])); } static ssize_t in_min_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->in_min); struct i2c_client *client = data->client; long val; int err; @@ -880,16 +889,16 @@ static ssize_t in_min_store(struct device *dev, struct device_attribute *attr, static ssize_t in_max_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->in_max); return sprintf(buf, "%d\n", INS_FROM_REG(nr, data->in_max[nr])); } static ssize_t in_max_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->in_max); struct i2c_client *client = data->client; long val; int err; @@ -935,8 +944,8 @@ static SENSOR_DEVICE_ATTR_RW(in7_max, in_max, 7); static ssize_t temp_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->temp); return sprintf(buf, "%d\n", TEMPEXT_FROM_REG(data->temp[nr], data->temp_ext[nr])); } @@ -944,8 +953,8 @@ static ssize_t temp_show(struct device *dev, struct device_attribute *attr, static ssize_t temp_min_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->temp_min); return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_min[nr])); } @@ -953,8 +962,8 @@ static ssize_t temp_min_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->temp_min); struct i2c_client *client = data->client; long val; int err; @@ -976,8 +985,8 @@ static ssize_t temp_min_store(struct device *dev, static ssize_t temp_max_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->temp_max); return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp_max[nr])); } @@ -985,8 +994,8 @@ static ssize_t temp_max_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->temp_max); struct i2c_client *client = data->client; long val; int err; @@ -1021,8 +1030,8 @@ static ssize_t pwm_auto_channels_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); return sprintf(buf, "%d\n", ZONE_FROM_REG(data->autofan[nr].config)); } @@ -1030,8 +1039,8 @@ static ssize_t pwm_auto_channels_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); struct i2c_client *client = data->client; long val; int err; @@ -1052,8 +1061,8 @@ static ssize_t pwm_auto_channels_store(struct device *dev, static ssize_t pwm_auto_pwm_min_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); return sprintf(buf, "%d\n", PWM_FROM_REG(data->autofan[nr].min_pwm)); } @@ -1061,8 +1070,8 @@ static ssize_t pwm_auto_pwm_min_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); struct i2c_client *client = data->client; unsigned long val; int err; @@ -1083,8 +1092,8 @@ static ssize_t pwm_auto_pwm_minctl_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); return sprintf(buf, "%d\n", data->autofan[nr].min_off); } @@ -1092,8 +1101,8 @@ static ssize_t pwm_auto_pwm_minctl_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->autofan); struct i2c_client *client = data->client; u8 tmp; long val; @@ -1130,8 +1139,8 @@ static ssize_t temp_auto_temp_off_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->zone); return sprintf(buf, "%d\n", TEMP_FROM_REG(data->zone[nr].limit) - HYST_FROM_REG(data->zone[nr].hyst)); } @@ -1140,8 +1149,8 @@ static ssize_t temp_auto_temp_off_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->zone); struct i2c_client *client = data->client; int min; long val; @@ -1170,8 +1179,8 @@ static ssize_t temp_auto_temp_min_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->zone); return sprintf(buf, "%d\n", TEMP_FROM_REG(data->zone[nr].limit)); } @@ -1179,8 +1188,8 @@ static ssize_t temp_auto_temp_min_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->zone); struct i2c_client *client = data->client; long val; int err; @@ -1194,7 +1203,7 @@ static ssize_t temp_auto_temp_min_store(struct device *dev, lm85_write_value(client, LM85_REG_AFAN_LIMIT(nr), data->zone[nr].limit); -/* Update temp_auto_max and temp_auto_range */ + /* Update temp_auto_max and temp_auto_range */ data->zone[nr].range = RANGE_TO_REG( TEMP_FROM_REG(data->zone[nr].max_desired) - TEMP_FROM_REG(data->zone[nr].limit)); @@ -1210,8 +1219,8 @@ static ssize_t temp_auto_temp_max_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->zone); return sprintf(buf, "%d\n", TEMP_FROM_REG(data->zone[nr].limit) + RANGE_FROM_REG(data->zone[nr].range)); } @@ -1220,8 +1229,8 @@ static ssize_t temp_auto_temp_max_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->zone); struct i2c_client *client = data->client; int min; long val; @@ -1247,8 +1256,8 @@ static ssize_t temp_auto_temp_crit_show(struct device *dev, struct device_attribute *attr, char *buf) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = lm85_update_device(dev); + unsigned int nr = get_sensor_index(attr, data->zone); return sprintf(buf, "%d\n", TEMP_FROM_REG(data->zone[nr].critical)); } @@ -1256,8 +1265,8 @@ static ssize_t temp_auto_temp_crit_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - int nr = to_sensor_dev_attr(attr)->index; struct lm85_data *data = dev_get_drvdata(dev); + unsigned int nr = get_sensor_index(attr, data->zone); struct i2c_client *client = data->client; long val; int err; diff --git a/include/linux/hwmon-sysfs.h b/include/linux/hwmon-sysfs.h index d896713359cd..f0505d10bfad 100644 --- a/include/linux/hwmon-sysfs.h +++ b/include/linux/hwmon-sysfs.h @@ -10,7 +10,7 @@ #include #include -struct sensor_device_attribute{ +struct sensor_device_attribute { struct device_attribute dev_attr; int index; };