ixgbe: cleanup ixgbe_get_drvinfo to be extra careful with buffer boundaries

Make the code in ixgbe_get_drvinfo more protected against buffer overflow
boundaries by using snprintf and sizeof with snprintf.

Signed-off-by: Don Skidmore <donald.c.skidmore@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 13 insertions, 10 deletions

diff --git a/drivers/net/ixgbe/ixgbe_ethtool.c b/drivers/net/ixgbe/ixgbe_ethtool.c
index dcebc82c6f4d..fb6d8e88eb05 100644
--- a/drivers/net/ixgbe/ixgbe_ethtool.c
+++ b/drivers/net/ixgbe/ixgbe_ethtool.c
@@ -820,16 +820,19 @@ static void ixgbe_get_drvinfo(struct net_device *netdev,
         struct ixgbe_adapter *adapter = netdev_priv(netdev);
         char firmware_version[32];
 
-        strncpy(drvinfo->driver, ixgbe_driver_name, 32);
-        strncpy(drvinfo->version, ixgbe_driver_version, 32);
-
-        sprintf(firmware_version, "%d.%d-%d",
-                (adapter->eeprom_version & 0xF000) >> 12,
-                (adapter->eeprom_version & 0x0FF0) >> 4,
-                adapter->eeprom_version & 0x000F);
-
-        strncpy(drvinfo->fw_version, firmware_version, 32);
-        strncpy(drvinfo->bus_info, pci_name(adapter->pdev), 32);
+        strncpy(drvinfo->driver, ixgbe_driver_name, sizeof(drvinfo->driver));
+        strncpy(drvinfo->version, ixgbe_driver_version,
+                sizeof(drvinfo->version));
+
+        snprintf(firmware_version, sizeof(firmware_version), "%d.%d-%d",
+                 (adapter->eeprom_version & 0xF000) >> 12,
+                 (adapter->eeprom_version & 0x0FF0) >> 4,
+                 adapter->eeprom_version & 0x000F);
+
+        strncpy(drvinfo->fw_version, firmware_version,
+                sizeof(drvinfo->fw_version));
+        strncpy(drvinfo->bus_info, pci_name(adapter->pdev),
+                sizeof(drvinfo->bus_info));
         drvinfo->n_stats = IXGBE_STATS_LEN;
         drvinfo->testinfo_len = IXGBE_TEST_LEN;
         drvinfo->regdump_len = ixgbe_get_regs_len(netdev);