e1000e: enhance frame fragment detection

Originally patched by Neil Horman <nhorman@tuxdriver.com>

e1000e could with a jumbo frame enabled interface, and packet split disabled,
receive a packet that would overflow a single rx buffer.  While in practice
very hard to craft a packet that could abuse this, it is possible.

this is related to CVE-2009-4538

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Jesse Brandeburg 2010-01-19 14:15:59 +00:00 committed by David S. Miller
parent 40a14deaf4
commit b94b502896
2 changed files with 22 additions and 4 deletions

View file

@ -421,6 +421,7 @@ struct e1000_info {
/* CRC Stripping defines */
#define FLAG2_CRC_STRIPPING (1 << 0)
#define FLAG2_HAS_PHY_WAKEUP (1 << 1)
#define FLAG2_IS_DISCARDING (1 << 2)
#define E1000_RX_DESC_PS(R, i) \
(&(((union e1000_rx_desc_packet_split *)((R).desc))[i]))

View file

@ -450,13 +450,23 @@ static bool e1000_clean_rx_irq(struct e1000_adapter *adapter,
length = le16_to_cpu(rx_desc->length);
/* !EOP means multiple descriptors were used to store a single
* packet, also make sure the frame isn't just CRC only */
if (!(status & E1000_RXD_STAT_EOP) || (length <= 4)) {
/*
* !EOP means multiple descriptors were used to store a single
* packet, if that's the case we need to toss it. In fact, we
* need to toss every packet with the EOP bit clear and the
* next frame that _does_ have the EOP bit set, as it is by
* definition only a frame fragment
*/
if (unlikely(!(status & E1000_RXD_STAT_EOP)))
adapter->flags2 |= FLAG2_IS_DISCARDING;
if (adapter->flags2 & FLAG2_IS_DISCARDING) {
/* All receives must fit into a single buffer */
e_dbg("Receive packet consumed multiple buffers\n");
/* recycle */
buffer_info->skb = skb;
if (status & E1000_RXD_STAT_EOP)
adapter->flags2 &= ~FLAG2_IS_DISCARDING;
goto next_desc;
}
@ -745,10 +755,16 @@ static bool e1000_clean_rx_irq_ps(struct e1000_adapter *adapter,
PCI_DMA_FROMDEVICE);
buffer_info->dma = 0;
if (!(staterr & E1000_RXD_STAT_EOP)) {
/* see !EOP comment in other rx routine */
if (!(staterr & E1000_RXD_STAT_EOP))
adapter->flags2 |= FLAG2_IS_DISCARDING;
if (adapter->flags2 & FLAG2_IS_DISCARDING) {
e_dbg("Packet Split buffers didn't pick up the full "
"packet\n");
dev_kfree_skb_irq(skb);
if (staterr & E1000_RXD_STAT_EOP)
adapter->flags2 &= ~FLAG2_IS_DISCARDING;
goto next_desc;
}
@ -1118,6 +1134,7 @@ static void e1000_clean_rx_ring(struct e1000_adapter *adapter)
rx_ring->next_to_clean = 0;
rx_ring->next_to_use = 0;
adapter->flags2 &= ~FLAG2_IS_DISCARDING;
writel(0, adapter->hw.hw_addr + rx_ring->head);
writel(0, adapter->hw.hw_addr + rx_ring->tail);