From 71638a456852a18a4578f52d51926ba1d223053b Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Mon, 3 Aug 2026 11:40:50 -0700 Subject: [PATCH 01/11] hwmon: (pmbus/core) Avoid race condition during probe pmbus_write_smbalert_mask() is not guarded, which can cause race conditions with concurrent sysfs attribute accesses. Similar, PMBus accesses in pmbus_init_debugfs() are not guarded, also resulting in potential race conditions. Add guards to both functions to prevent the races. Reported-by: Sashiko Fixes: 221819ca4c36e ("hwmon: (pmbus/core) Add interrupt support") Fixes: 1e069dfd96dfe ("hwmon: (pmbus) Add debugfs for status registers") Signed-off-by: Guenter Roeck --- drivers/hwmon/pmbus/pmbus_core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index 5567d37f13fe..095e128709af 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -3427,6 +3427,8 @@ static int pmbus_write_smbalert_mask(struct i2c_client *client, u8 page, u8 reg, { int ret; + guard(pmbus_lock)(client); + ret = _pmbus_write_word_data(client, page, PMBUS_SMBALERT_MASK, reg | (val << 8)); /* @@ -3662,6 +3664,8 @@ static void pmbus_init_debugfs(struct i2c_client *client, if (!entries) return; + guard(pmbus_lock)(client); + /* * Add device-specific entries. * Please note that the PMBUS standard allows all registers to be From 59bd68ab05a8f9c9a60b6ec44682084184803ff4 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 23 Jul 2026 10:57:35 -0700 Subject: [PATCH 02/11] hwmon: (pmbus) Fix type confusion in notification logic Sashiko reports: At the start of the loop in pmbus_notify(), the code unconditionally casts every attribute to a struct sensor_device_attribute: drivers/hwmon/pmbus/pmbus_core.c:pmbus_notify() { for (i = 0; i < data->num_attributes; i++) { struct device_attribute *da = to_dev_attr(data->group.attrs[i]); struct sensor_device_attribute *attr = to_sensor_dev_attr(da); int index = attr->index; ... } However, data->group.attrs can contain other types like struct pmbus_samples_reg or struct pmbus_sensor, which only embed a base struct device_attribute. If da is a struct pmbus_samples_reg, dev_attr is the last member. Casting it to struct sensor_device_attribute and reading the index field appears to access memory past the end of the allocation, which might trigger a slab-out-of-bounds read. Additionally, if da is a struct pmbus_sensor, casting it causes the index field to overlap with the page, phase, and reg fields. Could this produce a garbage mask on little-endian systems that spuriously matches the target reg, page, and flags during an alert? Fix the problem by using struct sensor_device_attr in struct pmbus_sensor and struct pmbus_label. Since those attributes never trigger a notification, set the value of attr->index to -1 for them. Use this value to distinguish from boolean attributes which _can_ trigger a notification and use the index field to encode mask, page, and register values. Fixes: f469bde9afd1 ("hwmon: (pmbus/core) Notify hwmon events") Cc: Vincent Jardin Tested-by: Vincent Jardin Signed-off-by: Guenter Roeck --- drivers/hwmon/pmbus/pmbus_core.c | 61 +++++++++++++++++++------------- 1 file changed, 37 insertions(+), 24 deletions(-) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index 095e128709af..3b219ed5386f 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -45,7 +45,7 @@ module_param(wp, int, 0444); struct pmbus_sensor { struct pmbus_sensor *next; char name[PMBUS_NAME_SIZE]; /* sysfs sensor name */ - struct device_attribute attribute; + struct sensor_device_attribute attribute; u8 page; /* page number */ u8 phase; /* phase number, 0xff for all phases */ u16 reg; /* register */ @@ -68,7 +68,7 @@ struct pmbus_boolean { struct pmbus_label { char name[PMBUS_NAME_SIZE]; /* sysfs label name */ - struct device_attribute attribute; + struct sensor_device_attribute attribute; char label[PMBUS_NAME_SIZE]; /* label */ }; #define to_pmbus_label(_attr) \ @@ -1241,7 +1241,8 @@ static ssize_t pmbus_show_sensor(struct device *dev, struct device_attribute *devattr, char *buf) { struct i2c_client *client = to_i2c_client(dev->parent); - struct pmbus_sensor *sensor = to_pmbus_sensor(devattr); + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); + struct pmbus_sensor *sensor = to_pmbus_sensor(attr); struct pmbus_data *data = i2c_get_clientdata(client); s64 val; @@ -1261,7 +1262,8 @@ static ssize_t pmbus_set_sensor(struct device *dev, { struct i2c_client *client = to_i2c_client(dev->parent); struct pmbus_data *data = i2c_get_clientdata(client); - struct pmbus_sensor *sensor = to_pmbus_sensor(devattr); + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); + struct pmbus_sensor *sensor = to_pmbus_sensor(attr); s64 val; int ret; u16 regval; @@ -1283,7 +1285,8 @@ static ssize_t pmbus_set_sensor(struct device *dev, static ssize_t pmbus_show_label(struct device *dev, struct device_attribute *da, char *buf) { - struct pmbus_label *label = to_pmbus_label(da); + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); + struct pmbus_label *label = to_pmbus_label(attr); return sysfs_emit(buf, "%s\n", label->label); } @@ -1436,8 +1439,8 @@ static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data, bool update, bool readonly, bool writeonly, bool convert) { + struct sensor_device_attribute *a; struct pmbus_sensor *sensor; - struct device_attribute *a; sensor = devm_kzalloc(data->dev, sizeof(*sensor), GFP_KERNEL); if (!sensor) @@ -1461,12 +1464,11 @@ static struct pmbus_sensor *pmbus_add_sensor(struct pmbus_data *data, sensor->update = update; sensor->convert = convert; sensor->data = -ENODATA; - pmbus_dev_attr_init(a, sensor->name, - readonly ? 0444 : 0644, - writeonly ? pmbus_show_zero : pmbus_show_sensor, - pmbus_set_sensor); + pmbus_attr_init(a, sensor->name, readonly ? 0444 : 0644, + writeonly ? pmbus_show_zero : pmbus_show_sensor, + pmbus_set_sensor, -1); - if (pmbus_add_attribute(data, &a->attr)) + if (pmbus_add_attribute(data, &a->dev_attr.attr)) return NULL; sensor->next = data->sensors; @@ -1483,8 +1485,8 @@ static int pmbus_add_label(struct pmbus_data *data, const char *name, int seq, const char *lstring, int index, int phase) { + struct sensor_device_attribute *a; struct pmbus_label *label; - struct device_attribute *a; label = devm_kzalloc(data->dev, sizeof(*label), GFP_KERNEL); if (!label) @@ -1508,8 +1510,8 @@ static int pmbus_add_label(struct pmbus_data *data, lstring, index, phase); } - pmbus_dev_attr_init(a, label->name, 0444, pmbus_show_label, NULL); - return pmbus_add_attribute(data, &a->attr); + pmbus_attr_init(a, label->name, 0444, pmbus_show_label, NULL, -1); + return pmbus_add_attribute(data, &a->dev_attr.attr); } /* @@ -2397,7 +2399,7 @@ struct pmbus_samples_attr { struct pmbus_samples_reg { int page; struct pmbus_samples_attr *attr; - struct device_attribute dev_attr; + struct sensor_device_attribute attribute; }; static struct pmbus_samples_attr pmbus_samples_registers[] = { @@ -2419,14 +2421,15 @@ static struct pmbus_samples_attr pmbus_samples_registers[] = { } }; -#define to_samples_reg(x) container_of(x, struct pmbus_samples_reg, dev_attr) +#define to_samples_reg(x) container_of(x, struct pmbus_samples_reg, attribute) static ssize_t pmbus_show_samples(struct device *dev, struct device_attribute *devattr, char *buf) { int val; struct i2c_client *client = to_i2c_client(dev->parent); - struct pmbus_samples_reg *reg = to_samples_reg(devattr); + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); + struct pmbus_samples_reg *reg = to_samples_reg(attr); scoped_guard(pmbus_lock, client) { val = _pmbus_read_word_data(client, reg->page, 0xff, reg->attr->reg); @@ -2444,7 +2447,8 @@ static ssize_t pmbus_set_samples(struct device *dev, int ret; long val; struct i2c_client *client = to_i2c_client(dev->parent); - struct pmbus_samples_reg *reg = to_samples_reg(devattr); + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); + struct pmbus_samples_reg *reg = to_samples_reg(attr); if (kstrtol(buf, 0, &val) < 0) return -EINVAL; @@ -2459,6 +2463,7 @@ static ssize_t pmbus_set_samples(struct device *dev, static int pmbus_add_samples_attr(struct pmbus_data *data, int page, struct pmbus_samples_attr *attr) { + struct sensor_device_attribute *a; struct pmbus_samples_reg *reg; reg = devm_kzalloc(data->dev, sizeof(*reg), GFP_KERNEL); @@ -2468,10 +2473,12 @@ static int pmbus_add_samples_attr(struct pmbus_data *data, int page, reg->attr = attr; reg->page = page; - pmbus_dev_attr_init(®->dev_attr, attr->name, 0644, - pmbus_show_samples, pmbus_set_samples); + a = ®->attribute; - return pmbus_add_attribute(data, ®->dev_attr.attr); + pmbus_attr_init(a, attr->name, 0644, + pmbus_show_samples, pmbus_set_samples, -1); + + return pmbus_add_attribute(data, &a->dev_attr.attr); } static int pmbus_add_samples_attributes(struct i2c_client *client, @@ -2979,9 +2986,15 @@ static void pmbus_notify(struct pmbus_data *data, int page, int reg, int flags) struct device_attribute *da = to_dev_attr(data->group.attrs[i]); struct sensor_device_attribute *attr = to_sensor_dev_attr(da); int index = attr->index; - u16 smask = pb_index_to_mask(index); - u8 spage = pb_index_to_page(index); - u16 sreg = pb_index_to_reg(index); + u16 smask, sreg; + u8 spage; + + if (index == -1) + continue; + + smask = pb_index_to_mask(index); + spage = pb_index_to_page(index); + sreg = pb_index_to_reg(index); if (reg == sreg && page == spage && (smask & flags)) { dev_dbg(data->dev, "sysfs notify: %s", da->attr.name); From d533882ce1060866a590257f2c77ee23eabef5b8 Mon Sep 17 00:00:00 2001 From: Qingshuang Fu Date: Tue, 4 Aug 2026 15:48:42 +0800 Subject: [PATCH 03/11] hwmon: (nzxt-smart2) Check return value of init_device() in probe The init_device() call in nzxt_smart2_hid_probe() can fail because it sends HID output reports to the hardware to detect fans and set the update interval. If the hardware is not responding or the HID reports fail, init_device() returns a negative error code. However, the return value was ignored, causing the probe to continue and register an hwmon device even though the device was never properly initialized. This leads to an inconsistent state where the driver reports stale data or blocks on wait queues that will never be woken. The same function's return value is already checked in the reset_resume() handler, confirming the author's intent that errors should be propagated. Note that this fix was not possible before commit 59d104b54b0b ("hwmon: (nzxt-smart2) Stop device IO before calling hid_hw_stop") because the out_hw_close error path was missing hid_device_io_stop(), which would have opened a use-after-free risk window. Fixes: 53e68c20aeb1 ("hwmon: add driver for NZXT RGB&Fan Controller/Smart Device v2.") Signed-off-by: Qingshuang Fu Link: https://lore.kernel.org/r/20260804074842.505923-1-fffsqian@163.com Signed-off-by: Guenter Roeck --- drivers/hwmon/nzxt-smart2.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/nzxt-smart2.c b/drivers/hwmon/nzxt-smart2.c index ff0c0bee0e83..efc78a8f58c8 100644 --- a/drivers/hwmon/nzxt-smart2.c +++ b/drivers/hwmon/nzxt-smart2.c @@ -754,7 +754,11 @@ static int nzxt_smart2_hid_probe(struct hid_device *hdev, hid_device_io_start(hdev); - init_device(drvdata, UPDATE_INTERVAL_DEFAULT_MS); + ret = init_device(drvdata, UPDATE_INTERVAL_DEFAULT_MS); + if (ret) { + dev_err(&hdev->dev, "init_device failed: %d\n", ret); + goto out_hw_close; + } drvdata->hwmon = hwmon_device_register_with_info(&hdev->dev, "nzxtsmart2", drvdata, From 0dabe8a56f772f0ece46d2597799f412c277d874 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 4 Aug 2026 14:12:31 -0700 Subject: [PATCH 04/11] hwmon: (pmbus/lm25066) Fix PMBus coefficient calculations In lm25066_probe(), the PMBus coefficients for current and power are scaled based on the shunt resistor value. The calculation evaluates the multiplication using 32-bit arithmetic because info->m is an int and shunt is a u32: static int lm25066_probe(struct i2c_client *client) { ... info->m[PSC_CURRENT_IN] = info->m[PSC_CURRENT_IN] * shunt / 1000; info->m[PSC_POWER] = info->m[PSC_POWER] * shunt / 1000; ... } For large coefficients like 26882 (LM25056) or 15076 (LM5066i), a device tree shunt-resistor-micro-ohms value exceeding approximately 159,000 (159 mOhm, which is physically valid for low-current applications) causes the intermediate product to exceed UINT_MAX (4,294,967,295). This results in a silent wraparound before the division by 1000. Furthermore, if the wrapped value has the most significant bit set, converting it back to the signed int info->m results in negative coefficients. This logic error leads to drastically corrupted current and power readings, which can cause erratic thermal or power management behavior in the system. Fix the problem by using 64-bit operations for the multiply/divide operations. This can still overflow, but only for unreasonably large shunt resistor values. Reported-by: Sashiko Fixes: 94ee5fcc240fe ("hwmon: (pmbus/lm25066) Support configurable sense resistor values") Signed-off-by: Guenter Roeck --- drivers/hwmon/pmbus/lm25066.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/pmbus/lm25066.c b/drivers/hwmon/pmbus/lm25066.c index 2be50cf1bbde..c797e2e8258f 100644 --- a/drivers/hwmon/pmbus/lm25066.c +++ b/drivers/hwmon/pmbus/lm25066.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include "pmbus.h" @@ -542,8 +543,8 @@ static int lm25066_probe(struct i2c_client *client) if (of_property_read_u32(client->dev.of_node, "shunt-resistor-micro-ohms", &shunt)) shunt = 1000; - info->m[PSC_CURRENT_IN] = info->m[PSC_CURRENT_IN] * shunt / 1000; - info->m[PSC_POWER] = info->m[PSC_POWER] * shunt / 1000; + info->m[PSC_CURRENT_IN] = DIV_ROUND_CLOSEST_ULL((u64)info->m[PSC_CURRENT_IN] * shunt, 1000); + info->m[PSC_POWER] = DIV_ROUND_CLOSEST_ULL((u64)info->m[PSC_POWER] * shunt, 1000); #if IS_ENABLED(CONFIG_SENSORS_LM25066_REGULATOR) /* LM25056 doesn't support OPERATION */ From 36c4d73ce05d1d8896c2669eb0730d35a02a2ec1 Mon Sep 17 00:00:00 2001 From: Wilken Gottwalt Date: Wed, 5 Aug 2026 07:19:20 +0000 Subject: [PATCH 05/11] hwmon: (corsair-psu) fix possible out-of-bounds access on missing string termination In theory it could be possible that the REPLY_SIZE sized buffers for holding the vendor and product strings could be end up missing the null termination (for example by malicious hardware built on purpose) required by the seq_printf() call. That limits the debugfs printf calls to a maximum string length of REPLY_SIZE. Fixes: d115b51e0e567 ("hwmon: add Corsair PSU HID controller driver") Signed-off-by: Wilken Gottwalt Link: https://lore.kernel.org/r/anLj9gPWRoRDbQBV@monster.localdomain Signed-off-by: Guenter Roeck --- drivers/hwmon/corsair-psu.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/hwmon/corsair-psu.c b/drivers/hwmon/corsair-psu.c index ce958cdaef58..3c01ae3fc4af 100644 --- a/drivers/hwmon/corsair-psu.c +++ b/drivers/hwmon/corsair-psu.c @@ -701,7 +701,7 @@ static int vendor_show(struct seq_file *seqf, void *unused) { struct corsairpsu_data *priv = seqf->private; - seq_printf(seqf, "%s\n", priv->vendor); + seq_printf(seqf, "%.*s\n", REPLY_SIZE, priv->vendor); return 0; } @@ -711,7 +711,7 @@ static int product_show(struct seq_file *seqf, void *unused) { struct corsairpsu_data *priv = seqf->private; - seq_printf(seqf, "%s\n", priv->product); + seq_printf(seqf, "%.*s\n", REPLY_SIZE, priv->product); return 0; } From fddb5ceaf901b050ed2a1a7deeecbf97e003435a Mon Sep 17 00:00:00 2001 From: Qingshuang Fu Date: Wed, 5 Aug 2026 14:16:45 +0800 Subject: [PATCH 06/11] hwmon: (ads7828) Fix external VREF regulator handling The driver currently has two issues with the external VREF regulator handling in ads7828_probe(): 1. All errors from devm_regulator_get_optional() are ignored, causing the driver to incorrectly fall back to internal VREF even for transient errors like -EPROBE_DEFER or genuine failures like -ENOMEM. 2. The external regulator is never enabled. The driver calls regulator_get_voltage() without first calling regulator_enable(), so the VREF pin may remain unpowered if the regulator is not configured as always-on. Fix both issues by switching to devm_regulator_get_enable_read_voltage(), which handles regulator get, enable, and voltage read in one call. Only -ENODEV (no regulator specified in device tree) should trigger the fallback to internal VREF. All other errors are propagated to the caller. Fixes: a8ddfea09566 ("hwmon: (ads7828) Accept optional parameters from device tree") Signed-off-by: Qingshuang Fu Link: https://lore.kernel.org/r/20260805061645.1331652-1-fffsqian@163.com Signed-off-by: Guenter Roeck --- drivers/hwmon/ads7828.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c index 149cfcec78dc..f8f2f621dfea 100644 --- a/drivers/hwmon/ads7828.c +++ b/drivers/hwmon/ads7828.c @@ -106,12 +106,11 @@ static int ads7828_probe(struct i2c_client *client) struct ads7828_data *data; struct device *hwmon_dev; unsigned int vref_mv = ADS7828_INT_VREF_MV; - unsigned int vref_uv; + int vref_uv; bool diff_input = false; bool ext_vref = false; unsigned int regval; enum ads7828_chips chip; - struct regulator *reg; data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL); if (!data) @@ -125,9 +124,11 @@ static int ads7828_probe(struct i2c_client *client) } else if (dev->of_node) { diff_input = of_property_read_bool(dev->of_node, "ti,differential-input"); - reg = devm_regulator_get_optional(dev, "vref"); - if (!IS_ERR(reg)) { - vref_uv = regulator_get_voltage(reg); + vref_uv = devm_regulator_get_enable_read_voltage(dev, "vref"); + if (vref_uv < 0) { + if (vref_uv != -ENODEV) + return vref_uv; + } else { vref_mv = DIV_ROUND_CLOSEST(vref_uv, 1000); if (vref_mv < ADS7828_EXT_VREF_MV_MIN || vref_mv > ADS7828_EXT_VREF_MV_MAX) From edd11a94335747423569500a194c6eaa915f2963 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 4 Aug 2026 15:42:42 -0700 Subject: [PATCH 07/11] hwmon: (ltc4282) Avoid overflow in maximum power calculation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit During device initialization in ltc4282_set_max_limits(), the calculation of the maximum power limit can suffer from a 32-bit integer overflow. static int ltc4282_set_max_limits(struct ltc4282_state *st) { ... st->power_max = DIV_ROUND_CLOSEST(st->vsense_max * DECA * MILLI, st->rsense) * st->vfs_out; ... } The result of DIV_ROUND_CLOSEST() evaluates to a 32-bit unsigned integer on 32-bit architectures. This result is then multiplied by st->vfs_out, which is a 16-bit unsigned integer. According to C promotion rules, since both operands are 32-bit or smaller, the multiplication is performed in 32-bit precision. If the device is configured with a low sense resistor value via the device tree (for example, 100 nano-ohms, resulting in st->rsense = 1) and the voltage is high, the division result can reach 343,750,000 and st->vfs_out can be 33,280. The product of these values is approximately 11.44 trillion, which exceeds the maximum capacity of a 32-bit integer and overflows before being stored in st->power_max. This overflow causes a truncated value to be assigned to st->power_max and written to the hardware limit register. An incorrect maximum power limit can trigger spurious power-bad faults or alarms, which may lead to the shutdown of the monitored power rail. Avoid the problem by calculating and storing the maximum power using 64-bit variables. Reported-by: Sashiko Fixes: cbc29538dbf7d ("hwmon: Add driver for LTC4282") Cc: Nuno Sa Reviewed-by: Nuno Sá Signed-off-by: Guenter Roeck --- drivers/hwmon/ltc4282.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/drivers/hwmon/ltc4282.c b/drivers/hwmon/ltc4282.c index cc698803f8bf..bb7f6727c44d 100644 --- a/drivers/hwmon/ltc4282.c +++ b/drivers/hwmon/ltc4282.c @@ -137,7 +137,7 @@ struct ltc4282_state { */ struct ltc4282_cache in0_1_cache[LTC4282_CHAN_VGPIO]; u32 vsense_max; - long power_max; + s64 power_max; u32 rsense; u16 vdd; u16 vfs_out; @@ -613,13 +613,12 @@ static int ltc4282_read(struct device *dev, enum hwmon_sensor_types type, } static int ltc4282_write_power_byte(const struct ltc4282_state *st, u32 reg, - long val) + s64 val) { u32 power; u64 temp; - if (val > st->power_max) - val = st->power_max; + val = clamp(val, 0, st->power_max); temp = val * int_pow(U8_MAX, 2) * st->rsense; power = DIV64_U64_ROUND_CLOSEST(temp, @@ -629,7 +628,7 @@ static int ltc4282_write_power_byte(const struct ltc4282_state *st, u32 reg, } static int ltc4282_write_power_word(const struct ltc4282_state *st, u32 reg, - long val) + u64 val) { u64 temp = int_pow(U16_MAX, 2) * st->rsense, temp_2; __be16 __raw; @@ -1222,7 +1221,8 @@ static int ltc4282_set_max_limits(struct ltc4282_state *st) return ret; /* Power is given by ISENSE * Vout. */ - st->power_max = DIV_ROUND_CLOSEST(st->vsense_max * DECA * MILLI, st->rsense) * st->vfs_out; + st->power_max = DIV_ROUND_CLOSEST_ULL((u64)st->vsense_max * DECA * MILLI, + st->rsense) * st->vfs_out; ret = ltc4282_write_power_byte(st, LTC4282_POWER_MAX, st->power_max); if (ret) return ret; From e253dd5f9f6d875a317895bf43ec9534ed7523cb Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 4 Aug 2026 16:26:05 -0700 Subject: [PATCH 08/11] hwmon: (ltc4282) Clamp negative current limits MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When a negative value is passed to ltc4282_write_curr(), the signed long val is cast directly to u64: drivers/hwmon/ltc4282.c:ltc4282_write_curr() { /* need to pass it in millivolt */ u32 in = DIV_ROUND_CLOSEST_ULL((u64)val * st->rsense, DECA * MICRO); ... } This cast converts negative inputs into large positive values. The subsequent division result overflows the u32 in variable, truncating to a pseudo-random positive value. When this is passed to ltc4282_write_voltage_byte(), it is clamped to the maximum limit instead of zero. Clamp val to 0 and to the maximum supported upper limit before the cast and assign the result to a 64-bit temporary variable before the division to avoid the underflow and an also possible overflow. Reported-by: Sashiko Fixes: cbc29538dbf7d ("hwmon: Add driver for LTC4282") Cc: Nuno Sa Reviewed-by: Nuno Sá Signed-off-by: Guenter Roeck --- drivers/hwmon/ltc4282.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/ltc4282.c b/drivers/hwmon/ltc4282.c index bb7f6727c44d..bb1bcb369016 100644 --- a/drivers/hwmon/ltc4282.c +++ b/drivers/hwmon/ltc4282.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include #include @@ -929,8 +930,11 @@ static int ltc4282_curr_reset_hist(struct ltc4282_state *st) static int ltc4282_write_curr(struct ltc4282_state *st, u32 attr, long val) { + s32 ulimit = min_t(u64, INT_MAX, + div_u64((u64)INT_MAX * DECA * MICRO, st->rsense)); + u64 val64 = clamp(val, 0, ulimit); /* need to pass it in millivolt */ - u32 in = DIV_ROUND_CLOSEST_ULL((u64)val * st->rsense, DECA * MICRO); + u32 in = DIV_ROUND_CLOSEST_ULL(val64 * st->rsense, DECA * MICRO); switch (attr) { case hwmon_curr_max: From 335698fd7f60b6707b21fda725f97f35fa956b07 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Tue, 4 Aug 2026 17:30:42 -0700 Subject: [PATCH 09/11] hwmon: (ltc4282) Fix parsing adi,current-limit-sense-microvolt MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ltc4282_parse_dt() evaluates the wrong variable when parsing the current limit. When the adi,current-limit-sense-microvolt property is parsed into st->vsense_max, the subsequent switch statement evaluates the unrelated val variable instead of st->vsense_max: drivers/hwmon/ltc4282.c:ltc4282_parse_dt() { ... ret = device_property_read_u32(dev, "adi,current-limit-sense-microvolt", &st->vsense_max); if (!ret) { int reg_val; switch (val) { case 12500: reg_val = 0; break; ... } Because val holds a small integer representing vin_mode (from 0 to 3), it never matches any of the valid current limit cases. This causes it to always fall through to the default error case, return -EINVAL, and aborts probe initialization for any device tree using this property. Validate st->vsense_max instead to fix the problem. Reported-by: Sashiko Fixes: cbc29538dbf7d ("hwmon: Add driver for LTC4282") Cc: Nuno Sa Reviewed-by: Nuno Sá Signed-off-by: Guenter Roeck --- drivers/hwmon/ltc4282.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/hwmon/ltc4282.c b/drivers/hwmon/ltc4282.c index bb1bcb369016..b1675dc5b3c7 100644 --- a/drivers/hwmon/ltc4282.c +++ b/drivers/hwmon/ltc4282.c @@ -1394,7 +1394,7 @@ static int ltc4282_setup(struct ltc4282_state *st, struct device *dev) if (!ret) { int reg_val; - switch (val) { + switch (st->vsense_max) { case 12500: reg_val = 0; break; From 2da6050809d437a805e7a3aa22398a15073b0234 Mon Sep 17 00:00:00 2001 From: Ali Ahmet Memis Date: Thu, 6 Aug 2026 14:21:39 +0000 Subject: [PATCH 10/11] hwmon: (corsair-psu) serialize debugfs access against hwmon corsairpsu_request() sends a rail select command and then the actual read as two separate transfers, both going through the single shared cmd_buffer and wait_completion in corsairpsu_usb_cmd(). The hwmon core serializes its own callers, but the debugfs files call corsairpsu_get_value() directly and never take that lock, so a debugfs read can land between another reader's rail select and its value read. The result is a value from the wrong rail reported as the right one, because corsairpsu_usb_cmd() only checks the command echo and both transfers echo the command it expects. It can also make a caller consume the reply meant for the other one, since raw_event() writes into the shared buffer and completes whoever happens to be waiting. Locking was dropped in commit 4207069edbf0 ("hwmon: (corsair-psu) Rely on subsystem locking") on the grounds that the subsystem serializes for us, which holds for sysfs but not for these files. Take the same lock in the debugfs paths that issue commands, using the guard added in commit d1e720c7328e ("hwmon: Support guard() and scoped_guard for subsystem locks"). The lock cannot go into corsairpsu_request() itself: the hwmon core already holds it across ->read, so every sysfs read would deadlock. vendor_show() and product_show() only print strings cached during probe and issue no command, and corsairpsu_get_criticals() and corsairpsu_check_cmd_support() run before either interface is registered, so none of them need it. Fixes: 4207069edbf0 ("hwmon: (corsair-psu) Rely on subsystem locking") Signed-off-by: Ali Ahmet Memis Tested-by: Wilken Gottwalt Link: https://lore.kernel.org/r/20260806142139.168611-1-ali@iusegentoo.com Signed-off-by: Guenter Roeck --- drivers/hwmon/corsair-psu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hwmon/corsair-psu.c b/drivers/hwmon/corsair-psu.c index 3c01ae3fc4af..ebcaddf337d8 100644 --- a/drivers/hwmon/corsair-psu.c +++ b/drivers/hwmon/corsair-psu.c @@ -664,6 +664,8 @@ static void print_uptime(struct seq_file *seqf, u8 cmd) long val; int ret; + guard(hwmon_lock)(priv->hwmon_dev); + ret = corsairpsu_get_value(priv, cmd, 0, &val); if (ret < 0) { seq_puts(seqf, "N/A\n"); @@ -723,6 +725,8 @@ static int ocpmode_show(struct seq_file *seqf, void *unused) long val; int ret; + guard(hwmon_lock)(priv->hwmon_dev); + /* * The rail mode is switchable on the fly. The RAW interface can be used for this. But it * will not be included here, because I consider it somewhat dangerous for the health of the From c6c4234928d2eb4f61fecb61067e612d9bdbd2ff Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Mon, 3 Aug 2026 20:48:11 -0700 Subject: [PATCH 11/11] hwmon: (corsair-psu) Fix linear11 calculation In corsairpsu_linear11_to_int(), the mantissa is extracted using bitwise operations and cast to s16 before being shifted left: static int corsairpsu_linear11_to_int(const u16 val, const int scale) { ... const int mant = (((s16)(val & 0x7ff)) << 5) >> 5; ... } Due to C integer promotion rules, the masked value (which is always positive) is promoted to a 32-bit integer before the left shift. As a result, the sign bit is never extended to bit 31 of the promoted integer. When the device hardware reports a negative temperature in Linear11 format (such as an ambient temperature probe reporting sub-zero), the negative mantissa is parsed incorrectly as a massive positive value. For example, -1 becomes 2047, which scales to 2047 degrees Celsius. Fix the problem by type casting the result of the left shift operation to s16. Another problem is left-shifting of negative values. In C, the result of left-shifting negative values is undefined. Use a multiplication instead to avoid the problem. Also use a local s64 variable to store temporary results, change the return value type from int to long, and clamp the final value to LONG_MIN and LONG_MAX to avoid under- and overflow issues while retaining as much information as possible. Reported-by: Sashiko Cc: Wilken Gottwalt Signed-off-by: Guenter Roeck Tested-by: Wilken Gottwalt Link: https://lore.kernel.org/r/20260804034811.2385506-1-linux@roeck-us.net Signed-off-by: Guenter Roeck --- drivers/hwmon/corsair-psu.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/drivers/hwmon/corsair-psu.c b/drivers/hwmon/corsair-psu.c index ebcaddf337d8..0cf072f86acb 100644 --- a/drivers/hwmon/corsair-psu.c +++ b/drivers/hwmon/corsair-psu.c @@ -137,13 +137,18 @@ struct corsairpsu_data { }; /* some values are SMBus LINEAR11 data which need a conversion */ -static int corsairpsu_linear11_to_int(const u16 val, const int scale) +static long corsairpsu_linear11_to_long(const u16 val, const int scale) { const int exp = ((s16)val) >> 11; - const int mant = (((s16)(val & 0x7ff)) << 5) >> 5; - const int result = mant * scale; + const int mant = ((s16)((val & 0x7ff) << 5)) >> 5; + s64 result = mant * scale; - return (exp >= 0) ? (result << exp) : (result >> -exp); + if (exp >= 0) + result *= (int)(1UL << exp); + else + result >>= -exp; + + return clamp(result, LONG_MIN, LONG_MAX); } /* the micro-controller uses percentage values to control pwm */ @@ -263,13 +268,13 @@ static int corsairpsu_get_value(struct corsairpsu_data *priv, u8 cmd, u8 rail, l case PSU_CMD_RAIL_AMPS: case PSU_CMD_TEMP0: case PSU_CMD_TEMP1: - *val = corsairpsu_linear11_to_int(tmp & 0xFFFF, 1000); + *val = corsairpsu_linear11_to_long(tmp & 0xFFFF, 1000); break; case PSU_CMD_FAN: - *val = corsairpsu_linear11_to_int(tmp & 0xFFFF, 1); + *val = corsairpsu_linear11_to_long(tmp & 0xFFFF, 1); break; case PSU_CMD_FAN_PWM_ENABLE: - *val = corsairpsu_linear11_to_int(tmp & 0xFFFF, 1); + *val = corsairpsu_linear11_to_long(tmp & 0xFFFF, 1); /* * 0 = automatic mode, means the micro-controller controls the fan using a plan * which can be modified, but changing this plan is not supported by this @@ -283,12 +288,12 @@ static int corsairpsu_get_value(struct corsairpsu_data *priv, u8 cmd, u8 rail, l *val = 2; break; case PSU_CMD_FAN_PWM: - *val = corsairpsu_linear11_to_int(tmp & 0xFFFF, 1); + *val = corsairpsu_linear11_to_long(tmp & 0xFFFF, 1); *val = corsairpsu_dutycycle_to_pwm(*val); break; case PSU_CMD_RAIL_WATTS: case PSU_CMD_TOTAL_WATTS: - *val = corsairpsu_linear11_to_int(tmp & 0xFFFF, 1000000); + *val = corsairpsu_linear11_to_long(tmp & 0xFFFF, 1000000); break; case PSU_CMD_TOTAL_UPTIME: case PSU_CMD_UPTIME: