From f7f49640bbb4339d71f8b713b04b8f401d5fc270 Mon Sep 17 00:00:00 2001 From: Benoît Ganne Date: Fri, 25 Oct 2019 15:26:27 +0200 Subject: ipsec: ipsec-input: check for too-short packets MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Make sure packet is big enough before processing it. Policy matching is done speculatively but is discarded if packet is too short. Type: fix Change-Id: I647db2c4e568b0d9bf2cfd5056e1b1c2e25132fe Signed-off-by: Benoît Ganne --- src/vnet/ipsec/ipsec_input.c | 37 +++++++++++++++++++++++++------------ 1 file changed, 25 insertions(+), 12 deletions(-) (limited to 'src/vnet/ipsec/ipsec_input.c') diff --git a/src/vnet/ipsec/ipsec_input.c b/src/vnet/ipsec/ipsec_input.c index 9fdbff5787f..61b10fb9db6 100644 --- a/src/vnet/ipsec/ipsec_input.c +++ b/src/vnet/ipsec/ipsec_input.c @@ -195,6 +195,7 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, ip4_ipsec_config_t *c0; ipsec_spd_t *spd0; ipsec_policy_t *p0 = 0; + u8 has_space0; bi0 = to_next[0] = from[0]; from += 1; @@ -230,8 +231,7 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, esp0 = (esp_header_t *) ((u8 *) esp0 + sizeof (udp_header_t)); } - /* FIXME TODO missing check whether there is enough data inside - * IP/UDP to contain ESP header & stuff ? */ + p0 = ipsec_input_protect_policy_match (spd0, clib_net_to_host_u32 (ip0->src_address. @@ -242,7 +242,12 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, clib_net_to_host_u32 (esp0->spi)); - if (PREDICT_TRUE (p0 != NULL)) + has_space0 = + vlib_buffer_has_space (b0, + (clib_address_t) (esp0 + 1) - + (clib_address_t) ip0); + + if (PREDICT_TRUE ((p0 != NULL) & (has_space0))) { ipsec_matched += 1; @@ -259,6 +264,7 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, } else { + p0 = 0; pi0 = ~0; }; @@ -271,10 +277,11 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, vlib_add_trace (vm, node, b0, sizeof (*tr)); tr->proto = ip0->protocol; - if (p0) - tr->sa_id = p0->sa_id; - tr->spi = clib_net_to_host_u32 (esp0->spi); - tr->seq = clib_net_to_host_u32 (esp0->seq); + tr->sa_id = p0 ? p0->sa_id : ~0; + tr->spi = + has_space0 ? clib_net_to_host_u32 (esp0->spi) : ~0; + tr->seq = + has_space0 ? clib_net_to_host_u32 (esp0->seq) : ~0; tr->spd = spd0->id; tr->policy_index = pi0; } @@ -292,7 +299,12 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, clib_net_to_host_u32 (ah0->spi)); - if (PREDICT_TRUE (p0 != 0)) + has_space0 = + vlib_buffer_has_space (b0, + (clib_address_t) (ah0 + 1) - + (clib_address_t) ip0); + + if (PREDICT_TRUE ((p0 != NULL) & (has_space0))) { ipsec_matched += 1; @@ -308,6 +320,7 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, } else { + p0 = 0; pi0 = ~0; } /* FIXME bypass and discard */ @@ -319,10 +332,10 @@ VLIB_NODE_FN (ipsec4_input_node) (vlib_main_t * vm, vlib_add_trace (vm, node, b0, sizeof (*tr)); tr->proto = ip0->protocol; - if (p0) - tr->sa_id = p0->sa_id; - tr->spi = clib_net_to_host_u32 (ah0->spi); - tr->seq = clib_net_to_host_u32 (ah0->seq_no); + tr->sa_id = p0 ? p0->sa_id : ~0; + tr->spi = has_space0 ? clib_net_to_host_u32 (ah0->spi) : ~0; + tr->seq = + has_space0 ? clib_net_to_host_u32 (ah0->seq_no) : ~0; tr->spd = spd0->id; tr->policy_index = pi0; } -- cgit 1.2.3-korg