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authorJesse Brandeburg <jesse.brandeburg@intel.com>2010-01-19 14:15:59 +0000
committerDavid S. Miller <davem@davemloft.net>2010-01-20 16:21:23 -0800
commitb94b50289622e816adc9f94111cfc2679c80177c (patch)
tree9545a229c7ef2dbdcdc8300fd4d84ff3cafc7808
parent40a14deaf411592b57cb0720f0e8004293ab9865 (diff)
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>
-rw-r--r--drivers/net/e1000e/e1000.h1
-rw-r--r--drivers/net/e1000e/netdev.c25
2 files changed, 22 insertions, 4 deletions
diff --git a/drivers/net/e1000e/e1000.h b/drivers/net/e1000e/e1000.h
index d6ee28f6ea0..d236efaf747 100644
--- a/drivers/net/e1000e/e1000.h
+++ b/drivers/net/e1000e/e1000.h
@@ -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]))
diff --git a/drivers/net/e1000e/netdev.c b/drivers/net/e1000e/netdev.c
index f91f247ed6a..1ea395b6c99 100644
--- a/drivers/net/e1000e/netdev.c
+++ b/drivers/net/e1000e/netdev.c
@@ -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);