`strncpy` is deprecated for use on NUL-terminated destination strings [1]. We should prefer more robust and less ambiguous string interfaces. `prop` is defined as this string literal with size 30 (including null): | #define SX9324_PROXRAW_DEF "semtech,ph01-proxraw-strength" | char prop[] = SX9324_PROXRAW_DEF; Each of the strncpy->strscpy replacements involve string literals with a size less than 30 which means there are no current problems with how strncpy is used. However, let's move away from using strncpy entirely. A suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Moreover, let's opt for the more conventional `sizeof()` as opposed to `ARRAY_SIZE` for these simple strings. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@xxxxxxxxxxxxxxx Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx> --- FWIW: It seems fragile to base future `prop` stores on the size of it's default string. Note: build-tested --- drivers/iio/proximity/sx9324.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/iio/proximity/sx9324.c b/drivers/iio/proximity/sx9324.c index 438f9c9aba6e..25ac2733bcef 100644 --- a/drivers/iio/proximity/sx9324.c +++ b/drivers/iio/proximity/sx9324.c @@ -937,11 +937,9 @@ 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)); + strscpy(prop, "semtech,ph01-resolution", sizeof(prop)); else - strncpy(prop, "semtech,ph23-resolution", - ARRAY_SIZE(prop)); + strscpy(prop, "semtech,ph23-resolution", sizeof(prop)); ret = device_property_read_u32(dev, prop, &raw); if (ret) @@ -1012,11 +1010,9 @@ 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)); + strscpy(prop, "semtech,ph01-proxraw-strength", sizeof(prop)); else - strncpy(prop, "semtech,ph23-proxraw-strength", - ARRAY_SIZE(prop)); + strscpy(prop, "semtech,ph23-proxraw-strength", sizeof(prop)); ret = device_property_read_u32(dev, prop, &raw); if (ret) break; --- base-commit: 2cf0f715623872823a72e451243bbf555d10d032 change-id: 20230921-strncpy-drivers-iio-proximity-sx9324-c-8c3437676039 Best regards, -- Justin Stitt <justinstitt@xxxxxxxxxx>
