diff options
| author | Anssi Hannula <anssi.hannula@bitwise.fi> | 2017-02-14 20:11:44 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-02-15 20:18:33 +0300 |
| commit | cd224553641848dd17800fe559e4ff5d208553e8 (patch) | |
| tree | e0c82bf644515f25f6a4f1e612b706ca7388dc76 | |
| parent | 5463b3d043826ff8ef487edbd1ef1bfffb677437 (diff) | |
| download | linux-cd224553641848dd17800fe559e4ff5d208553e8.tar.xz | |
net: xilinx_emaclite: fix receive buffer overflow
xilinx_emaclite looks at the received data to try to determine the
Ethernet packet length but does not properly clamp it if
proto_type == ETH_P_IP or 1500 < proto_type <= 1518, causing a buffer
overflow and a panic via skb_panic() as the length exceeds the allocated
skb size.
Fix those cases.
Also add an additional unconditional check with WARN_ON() at the end.
Signed-off-by: Anssi Hannula <anssi.hannula@bitwise.fi>
Fixes: bb81b2ddfa19 ("net: add Xilinx emac lite device driver")
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/xilinx/xilinx_emaclite.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/drivers/net/ethernet/xilinx/xilinx_emaclite.c b/drivers/net/ethernet/xilinx/xilinx_emaclite.c index 93dc10b10c09..455774e4741a 100644 --- a/drivers/net/ethernet/xilinx/xilinx_emaclite.c +++ b/drivers/net/ethernet/xilinx/xilinx_emaclite.c @@ -369,7 +369,7 @@ static int xemaclite_send_data(struct net_local *drvdata, u8 *data, * * Return: Total number of bytes received */ -static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data) +static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data, int maxlen) { void __iomem *addr; u16 length, proto_type; @@ -409,7 +409,7 @@ static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data) /* Check if received ethernet frame is a raw ethernet frame * or an IP packet or an ARP packet */ - if (proto_type > (ETH_FRAME_LEN + ETH_FCS_LEN)) { + if (proto_type > ETH_DATA_LEN) { if (proto_type == ETH_P_IP) { length = ((ntohl(__raw_readl(addr + @@ -417,6 +417,7 @@ static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data) XEL_RXBUFF_OFFSET)) >> XEL_HEADER_SHIFT) & XEL_RPLR_LENGTH_MASK); + length = min_t(u16, length, ETH_DATA_LEN); length += ETH_HLEN + ETH_FCS_LEN; } else if (proto_type == ETH_P_ARP) @@ -429,6 +430,9 @@ static u16 xemaclite_recv_data(struct net_local *drvdata, u8 *data) /* Use the length in the frame, plus the header and trailer */ length = proto_type + ETH_HLEN + ETH_FCS_LEN; + if (WARN_ON(length > maxlen)) + length = maxlen; + /* Read from the EmacLite device */ xemaclite_aligned_read((u32 __force *) (addr + XEL_RXBUFF_OFFSET), data, length); @@ -603,7 +607,7 @@ static void xemaclite_rx_handler(struct net_device *dev) skb_reserve(skb, 2); - len = xemaclite_recv_data(lp, (u8 *) skb->data); + len = xemaclite_recv_data(lp, (u8 *) skb->data, len); if (!len) { dev->stats.rx_errors++; |