MAC addresses can be written without leading zeros. A popular
example is libc's ether_ntoa_r function which creates such
MAC addresses.
Example:
00:14:3d:0f:ff:fe can be written as 0:14:3d:f:ff:fe
Additionally, get_ether_addr potentially parsed past the end
of the user provided string. Use the opportunity and fix the
function to never parse beyond the end of the string while
allowing MAC addresses with and without leading zeros.
Signed-off-by: Stefan Agner <stefan@xxxxxxxx>
---
drivers/usb/gadget/function/u_ether.c | 41 +++++++++++++++++++++--------------
1 file changed, 25 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
index f1fd777..9994645 100644
--- a/drivers/usb/gadget/function/u_ether.c
+++ b/drivers/usb/gadget/function/u_ether.c
@@ -705,23 +705,27 @@ static int eth_stop(struct net_device *net)
static int get_ether_addr(const char *str, u8 *dev_addr)
{
- if (str) {
- unsigned i;
+ int num, i = 0;
+ char c = *str;
- for (i = 0; i < 6; i++) {
- unsigned char num;
-
- if ((*str == '.') || (*str == ':'))
- str++;
- num = hex_to_bin(*str++) << 4;
- num |= hex_to_bin(*str++);
- dev_addr [i] = num;
+ dev_addr[i] = 0;
+ while (c && i < ETH_ALEN) {
+ if (c == '.' || c == ':') {
+ dev_addr[++i] = 0;
+ } else {
+ num = hex_to_bin(c);
+ if (num < 0)
+ break;
+ dev_addr[i] <<= 4;
+ dev_addr[i] |= num;
}
- if (is_valid_ether_addr(dev_addr))
- return 0;
+ c = *++str;
}
- eth_random_addr(dev_addr);
- return 1;
+
+ if ((i + 1) != ETH_ALEN || !is_valid_ether_addr(dev_addr))
+ return -EINVAL;
+
+ return 0;
}
static int get_ether_addr_str(u8 dev_addr[ETH_ALEN], char *str, int len)
@@ -786,12 +790,17 @@ struct eth_dev *gether_setup_name(struct usb_gadget *g,
dev->qmult = qmult;
snprintf(net->name, sizeof(net->name), "%s%%d", netname);
- if (get_ether_addr(dev_addr, net->dev_addr))
+ if (get_ether_addr(dev_addr, net->dev_addr)) {
+ eth_random_addr(net->dev_addr);
dev_warn(&g->dev,
"using random %s ethernet address\n", "self");
- if (get_ether_addr(host_addr, dev->host_mac))
+ }
+
+ if (get_ether_addr(host_addr, dev->host_mac)) {
+ eth_random_addr(dev->host_mac);
dev_warn(&g->dev,
"using random %s ethernet address\n", "host");
+ }
if (ethaddr)
memcpy(ethaddr, dev->host_mac, ETH_ALEN);
--
2.3.6
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