net/ncsi: handle overflow when incrementing mac address
Previously BMC's MAC address is calculated by simply adding 1 to the
last byte of network controller's MAC address, and it produces incorrect
result when network controller's MAC address ends with 0xFF.
The problem can be fixed by calling eth_addr_inc() function to increment
MAC address; besides, the MAC address is also validated before assigning
to BMC.
Fixes: cb10c7c0dfd9 ("net/ncsi: Add NCSI Broadcom OEM command")
Signed-off-by: Tao Ren <taoren@fb.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Samuel Mendoza-Jonas <sam@mendozajonas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ncsi/ncsi-rsp.c b/net/ncsi/ncsi-rsp.c
index dc07fcc..802db01 100644
--- a/net/ncsi/ncsi-rsp.c
+++ b/net/ncsi/ncsi-rsp.c
@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <net/ncsi.h>
@@ -667,7 +668,10 @@ static int ncsi_rsp_handler_oem_bcm_gma(struct ncsi_request *nr)
ndev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
memcpy(saddr.sa_data, &rsp->data[BCM_MAC_ADDR_OFFSET], ETH_ALEN);
/* Increase mac address by 1 for BMC's address */
- saddr.sa_data[ETH_ALEN - 1]++;
+ eth_addr_inc((u8 *)saddr.sa_data);
+ if (!is_valid_ether_addr((const u8 *)saddr.sa_data))
+ return -ENXIO;
+
ret = ops->ndo_set_mac_address(ndev, &saddr);
if (ret < 0)
netdev_warn(ndev, "NCSI: 'Writing mac address to device failed\n");