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 post@mikaelkw.online Signed-off-by: Mikael Wessel post@mikaelkw.online Cc: stable@vger.kernel.org --- 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++)