From 313a72ff983cc2e00ac4dcb791d40ebf2f9d5718 Mon Sep 17 00:00:00 2001 From: Srinivas Kandagatla Date: Tue, 17 Nov 2015 09:12:41 +0000 Subject: [PATCH] nvmem: core: return error for non word aligned access 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 Signed-off-by: Srinivas Kandagatla Signed-off-by: Greg Kroah-Hartman --- drivers/nvmem/core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c index 6fd4e5a5ef4a..9d11d9837312 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; -- 2.20.1