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authorSrinivas Kandagatla <srinivas.kandagatla@linaro.org>2015-12-14 10:42:38 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2016-02-08 08:09:13 +0100
commit2f9ba5b2f8420e0e5712080dafc773f7dd47c3df (patch)
tree3d63d41c671776a86dd02b4d7eca0011f158a091
parentmei: validate request value in client notify request ioctl (diff)
downloadlinux-2f9ba5b2f8420e0e5712080dafc773f7dd47c3df.tar.xz
linux-2f9ba5b2f8420e0e5712080dafc773f7dd47c3df.zip
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 <ariel@vanguardiasur.com.ar> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/nvmem/core.c6
1 files changed, 6 insertions, 0 deletions
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;