beceem: don't overrun user buffer on read

Serious bug in original code, if app reads 10 bytes but 20 byte msg
received memory would get overwritten.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
This commit is contained in:
Stephen Hemminger 2010-11-01 13:59:01 -04:00
parent 5cf084f44a
commit 9c5d77009d

View file

@ -139,7 +139,7 @@ static ssize_t bcm_char_read(struct file *filp, char __user *buf, size_t size, l
if(Packet)
{
PktLen = Packet->len;
if(copy_to_user(buf, Packet->data, PktLen))
if(copy_to_user(buf, Packet->data, min_t(size_t, PktLen, size)))
{
dev_kfree_skb(Packet);
BCM_DEBUG_PRINT(Adapter,DBG_TYPE_PRINTK, 0, 0, "\nReturning from copy to user failure \n");