linux/net/ipv4/raw.c

1032 lines
24 KiB

AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl (v2) Augment raw_send_hdrinc to correct for incorrect ip header length values A series of oopses was reported to me recently. Apparently when using AF_RAW sockets to send data to peers that were reachable via ipsec encapsulation, people could panic or BUG halt their systems. I've tracked the problem down to user space sending an invalid ip header over an AF_RAW socket with IP_HDRINCL set to 1. Basically what happens is that userspace sends down an ip frame that includes only the header (no data), but sets the ip header ihl value to a large number, one that is larger than the total amount of data passed to the sendmsg call. In raw_send_hdrincl, we allocate an skb based on the size of the data in the msghdr that was passed in, but assume the data is all valid. Later during ipsec encapsulation, xfrm4_tranport_output moves the entire frame back in the skbuff to provide headroom for the ipsec headers. During this operation, the skb->transport_header is repointed to a spot computed by skb->network_header + the ip header length (ihl). Since so little data was passed in relative to the value of ihl provided by the raw socket, we point transport header to an unknown location, resulting in various crashes. This fix for this is pretty straightforward, simply validate the value of of iph->ihl when sending over a raw socket. If (iph->ihl*4U) > user data buffer size, drop the frame and return -EINVAL. I just confirmed this fixes the reported crashes. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-28 08:59:47 +00:00
AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl (v2) Augment raw_send_hdrinc to correct for incorrect ip header length values A series of oopses was reported to me recently. Apparently when using AF_RAW sockets to send data to peers that were reachable via ipsec encapsulation, people could panic or BUG halt their systems. I've tracked the problem down to user space sending an invalid ip header over an AF_RAW socket with IP_HDRINCL set to 1. Basically what happens is that userspace sends down an ip frame that includes only the header (no data), but sets the ip header ihl value to a large number, one that is larger than the total amount of data passed to the sendmsg call. In raw_send_hdrincl, we allocate an skb based on the size of the data in the msghdr that was passed in, but assume the data is all valid. Later during ipsec encapsulation, xfrm4_tranport_output moves the entire frame back in the skbuff to provide headroom for the ipsec headers. During this operation, the skb->transport_header is repointed to a spot computed by skb->network_header + the ip header length (ihl). Since so little data was passed in relative to the value of ihl provided by the raw socket, we point transport header to an unknown location, resulting in various crashes. This fix for this is pretty straightforward, simply validate the value of of iph->ihl when sending over a raw socket. If (iph->ihl*4U) > user data buffer size, drop the frame and return -EINVAL. I just confirmed this fixes the reported crashes. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-28 08:59:47 +00:00
AF_RAW: Augment raw_send_hdrinc to expand skb to fit iphdr->ihl (v2) Augment raw_send_hdrinc to correct for incorrect ip header length values A series of oopses was reported to me recently. Apparently when using AF_RAW sockets to send data to peers that were reachable via ipsec encapsulation, people could panic or BUG halt their systems. I've tracked the problem down to user space sending an invalid ip header over an AF_RAW socket with IP_HDRINCL set to 1. Basically what happens is that userspace sends down an ip frame that includes only the header (no data), but sets the ip header ihl value to a large number, one that is larger than the total amount of data passed to the sendmsg call. In raw_send_hdrincl, we allocate an skb based on the size of the data in the msghdr that was passed in, but assume the data is all valid. Later during ipsec encapsulation, xfrm4_tranport_output moves the entire frame back in the skbuff to provide headroom for the ipsec headers. During this operation, the skb->transport_header is repointed to a spot computed by skb->network_header + the ip header length (ihl). Since so little data was passed in relative to the value of ihl provided by the raw socket, we point transport header to an unknown location, resulting in various crashes. This fix for this is pretty straightforward, simply validate the value of of iph->ihl when sending over a raw socket. If (iph->ihl*4U) > user data buffer size, drop the frame and return -EINVAL. I just confirmed this fixes the reported crashes. Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-28 08:59:47 +00:00
net: Generalize socket rx gap / receive queue overflow cmsg Create a new socket level option to report number of queue overflows Recently I augmented the AF_PACKET protocol to report the number of frames lost on the socket receive queue between any two enqueued frames. This value was exported via a SOL_PACKET level cmsg. AFter I completed that work it was requested that this feature be generalized so that any datagram oriented socket could make use of this option. As such I've created this patch, It creates a new SOL_SOCKET level option called SO_RXQ_OVFL, which when enabled exports a SOL_SOCKET level cmsg that reports the nubmer of times the sk_receive_queue overflowed between any two given frames. It also augments the AF_PACKET protocol to take advantage of this new feature (as it previously did not touch sk->sk_drops, which this patch uses to record the overflow count). Tested successfully by me. Notes: 1) Unlike my previous patch, this patch simply records the sk_drops value, which is not a number of drops between packets, but rather a total number of drops. Deltas must be computed in user space. 2) While this patch currently works with datagram oriented protocols, it will also be accepted by non-datagram oriented protocols. I'm not sure if thats agreeable to everyone, but my argument in favor of doing so is that, for those protocols which aren't applicable to this option, sk_drops will always be zero, and reporting no drops on a receive queue that isn't used for those non-participating protocols seems reasonable to me. This also saves us having to code in a per-protocol opt in mechanism. 3) This applies cleanly to net-next assuming that commit 977750076d98c7ff6cbda51858bb5a5894a9d9ab (my af packet cmsg patch) is reverted Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2009-10-12 13:26:31 -07:00