The ETHTOOL_SETEEPROM ioctl copies user data into a kmalloc'ed buffer
without validating eeprom->len and eeprom->offset.  A CAP_NET_ADMIN
user can overflow the heap and crash the kernel or gain code execution.

Validate length and offset before memcpy().

Fixes: bc7f75fa9788 ("[E1000E]: New pci-express e1000 driver (currently for 
ICH9 devices only)")
Reported-by: Mikael Wessel <[email protected]>
Signed-off-by: Mikael Wessel <[email protected]>
Cc: [email protected]
---
 drivers/net/ethernet/intel/e1000e/ethtool.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/e1000e/ethtool.c 
b/drivers/net/ethernet/intel/e1000e/ethtool.c
index 9364bc2b4eb1..98e541e39730 100644
--- a/drivers/net/ethernet/intel/e1000e/ethtool.c
+++ b/drivers/net/ethernet/intel/e1000e/ethtool.c
@@ -596,6 +596,9 @@ static int e1000_set_eeprom(struct net_device *netdev,
        for (i = 0; i < last_word - first_word + 1; i++)
                le16_to_cpus(&eeprom_buff[i]);
 
+        if (eeprom->len > max_len ||
+            eeprom->offset > max_len - eeprom->len)
+                return -EINVAL;
        memcpy(ptr, bytes, eeprom->len);
 
        for (i = 0; i < last_word - first_word + 1; i++)
-- 
2.48.1

Reply via email to