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 kmalloc() to avoid leaking eeprom_buff.
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 | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/ethtool.c
b/drivers/net/ethernet/intel/e1000e/ethtool.c
index 98e541e39730..d04e59528619 100644
--- a/drivers/net/ethernet/intel/e1000e/ethtool.c
+++ b/drivers/net/ethernet/intel/e1000e/ethtool.c
@@ -561,7 +561,7 @@ static int e1000_set_eeprom(struct net_device *netdev,
return -EOPNOTSUPP;
if (eeprom->magic !=
- (adapter->pdev->vendor | (adapter->pdev->device << 16)))
+ (adapter->pdev->vendor | (adapter->pdev->device << 16)))
return -EFAULT;
if (adapter->flags & FLAG_READ_ONLY_NVM)
@@ -569,6 +569,10 @@ static int e1000_set_eeprom(struct net_device *netdev,
max_len = hw->nvm.word_size * 2;
+ /* bounds check: offset + len must not exceed EEPROM size */
+ if (eeprom->offset + eeprom->len > max_len)
+ return -EINVAL;
+
first_word = eeprom->offset >> 1;
last_word = (eeprom->offset + eeprom->len - 1) >> 1;
eeprom_buff = kmalloc(max_len, GFP_KERNEL);
@@ -596,9 +600,6 @@ 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
