We're doing some needless string copies when trying to assign the proper `prop` string. We can make `prop` a const char* and simply assign to string literals. For the case where a format string is used, let's allocate some memory via kasprintf() and point prop to it. This also cleans up some deprecated strncpy() uses [1]. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@xxxxxxxxxxxxxxx Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> --- Changes in v2: - make prop a const char* and do simple assignments (thanks Jonathan) - rebase onto 3a568e3a961ba330 - Link to v1: https://lore.kernel.org/r/20230921-strncpy-drivers-iio-proximity-sx9324-c-v1-1-4e8d28fd1e7c@xxxxxxxxxx --- Note: build-tested --- drivers/iio/proximity/sx9324.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/drivers/iio/proximity/sx9324.c b/drivers/iio/proximity/sx9324.c index 438f9c9aba6e..c8547035cb47 100644 --- a/drivers/iio/proximity/sx9324.c +++ b/drivers/iio/proximity/sx9324.c @@ -885,7 +885,7 @@ sx9324_get_default_reg(struct device *dev, int idx, #define SX9324_RESOLUTION_DEF "semtech,ph01-resolution" #define SX9324_PROXRAW_DEF "semtech,ph01-proxraw-strength" unsigned int pin_defs[SX9324_NUM_PINS]; - char prop[] = SX9324_PROXRAW_DEF; + const char *prop = SX9324_PROXRAW_DEF; u32 start = 0, raw = 0, pos = 0; int ret, count, ph, pin; const char *res; @@ -899,7 +899,7 @@ sx9324_get_default_reg(struct device *dev, int idx, case SX9324_REG_AFE_PH2: case SX9324_REG_AFE_PH3: ph = reg_def->reg - SX9324_REG_AFE_PH0; - snprintf(prop, ARRAY_SIZE(prop), "semtech,ph%d-pin", ph); + prop = kasprintf(GFP_KERNEL, "semtech,ph%d-pin", ph); count = device_property_count_u32(dev, prop); if (count != ARRAY_SIZE(pin_defs)) @@ -913,6 +913,7 @@ sx9324_get_default_reg(struct device *dev, int idx, raw |= (pin_defs[pin] << (2 * pin)) & SX9324_REG_AFE_PH0_PIN_MASK(pin); reg_def->def = raw; + kfree(prop); break; case SX9324_REG_AFE_CTRL0: ret = device_property_read_string(dev, @@ -937,11 +938,9 @@ sx9324_get_default_reg(struct device *dev, int idx, case SX9324_REG_AFE_CTRL4: case SX9324_REG_AFE_CTRL7: if (reg_def->reg == SX9324_REG_AFE_CTRL4) - strncpy(prop, "semtech,ph01-resolution", - ARRAY_SIZE(prop)); + prop = "semtech,ph01-resolution"; else - strncpy(prop, "semtech,ph23-resolution", - ARRAY_SIZE(prop)); + prop = "semtech,ph23-resolution"; ret = device_property_read_u32(dev, prop, &raw); if (ret) @@ -1012,11 +1011,9 @@ sx9324_get_default_reg(struct device *dev, int idx, case SX9324_REG_PROX_CTRL0: case SX9324_REG_PROX_CTRL1: if (reg_def->reg == SX9324_REG_PROX_CTRL0) - strncpy(prop, "semtech,ph01-proxraw-strength", - ARRAY_SIZE(prop)); + prop = "semtech,ph01-proxraw-strength"; else - strncpy(prop, "semtech,ph23-proxraw-strength", - ARRAY_SIZE(prop)); + prop = "semtech,ph23-proxraw-strength"; ret = device_property_read_u32(dev, prop, &raw); if (ret) break; --- base-commit: 3a568e3a961ba330091cd031647e4c303fa0badb change-id: 20230921-strncpy-drivers-iio-proximity-sx9324-c-8c3437676039 Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
