From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 7002b526f4ff1f6da34356e67085caafa6be383a ]
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@oracle.com Link: https://lore.kernel.org/r/YMcoTPsCYlhh2TQo@mwanda Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 1eacf82d1bd0..8561f7fb53e9 100644 --- a/drivers/staging/gdm724x/gdm_lte.c +++ b/drivers/staging/gdm724x/gdm_lte.c @@ -624,10 +624,12 @@ 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); } }