nvmem providers have restrictions on register strides, so return error when users attempt to read/write buffers with sizes which are less than word size.
Without this patch the userspace would continue to try as it does not get any error from the nvmem core, resulting in a hang or endless loop in userspace. Reported-by: Ariel D'Alessandro <[email protected]> Signed-off-by: Srinivas Kandagatla <[email protected]> --- drivers/nvmem/core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 6fd4e5a..9d11d98 100644 --- a/drivers/nvmem/core.c +++ b/drivers/nvmem/core.c @@ -70,6 +70,9 @@ static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj, if (pos >= nvmem->size) return 0; + if (count < nvmem->word_size) + return -EINVAL; + if (pos + count > nvmem->size) count = nvmem->size - pos; @@ -95,6 +98,9 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj, if (pos >= nvmem->size) return 0; + if (count < nvmem->word_size) + return -EINVAL; + if (pos + count > nvmem->size) count = nvmem->size - pos; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
