This code assumes that "len" is at least 62 bytes, but we need a check
to prevent a read overflow.
Fixes: 61e121047645 ("staging: gdm7240: adding LTE USB driver")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
There is a different place that does:
ip_version = buf[0] >> 4;
Which assumes that "len" is one. I think that should be checked in the
caller... I didn't add a check here because I think it's the wrong
place but then I didn't add a check in the caller because I wasn't able
to test it. I'm not really that worried about reading one element
beyond the end of the buffer. If we get extremely unlucky it could
result in a crash... Hopefully we will remember to look at this again
before moving this code out of staging.
#TODO:
drivers/staging/gdm724x/gdm_lte.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/staging/gdm724x/gdm_lte.c b/drivers/staging/gdm724x/gdm_lte.c
index a41af7aa74ec..bd5f87433404 100644
--- a/drivers/staging/gdm724x/gdm_lte.c
+++ b/drivers/staging/gdm724x/gdm_lte.c
@@ -611,10 +611,12 @@ static void gdm_lte_netif_rx(struct net_device *dev, char *buf,
* bytes (99,130,83,99 dec)
*/
} __packed;
- void *addr = buf + sizeof(struct iphdr) +
- sizeof(struct udphdr) +
- offsetof(struct dhcp_packet, chaddr);
- ether_addr_copy(nic->dest_mac_addr, addr);
+ int offset = sizeof(struct iphdr) +
+ sizeof(struct udphdr) +
+ offsetof(struct dhcp_packet, chaddr);
+ if (offset + ETH_ALEN > len)
+ return;
+ ether_addr_copy(nic->dest_mac_addr, buf + offset);
}
}
--
2.30.2
