From: Phil Sutter <phil@nwl.cc>
Date: Tue, 13 Nov 2018 12:39:04 +0000 (+0100)
Subject: ip-route: Fix nexthop encap parsing
X-Git-Tag: v4.20.0~67^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=05d978e0850a6a3bae1e6c5392d82f7b1496f86a;p=thirdparty%2Fiproute2.git

ip-route: Fix nexthop encap parsing

When parsing nexthop parameters, a buffer of 4k bytes is provided. Yet,
in lwt_parse_encap() and some functions called by it, buffer size was
assumed to be 1k despite the actual size was provided. This led to
spurious buffer size errors if the buffer was filled by previous nexthop
parameters to exceed that 1k boundary.

Fixes: 1e5293056a02c ("lwtunnel: Add encapsulation support to ip route")
Fixes: 5866bddd9aa9e ("ila: Add support for ILA lwtunnels")
Fixes: ed67f83806538 ("ila: Support for checksum neutral translation")
Fixes: 86905c8f057c0 ("ila: support for configuring identifier and hook types")
Fixes: b15f440e78373 ("lwt: BPF support for LWT")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---

diff --git a/ip/iproute_lwtunnel.c b/ip/iproute_lwtunnel.c
index 8f4970150..85ab13cb3 100644
--- a/ip/iproute_lwtunnel.c
+++ b/ip/iproute_lwtunnel.c
@@ -860,7 +860,7 @@ static int parse_encap_ila(struct rtattr *rta, size_t len,
 
 	argc--; argv++;
 
-	if (rta_addattr64(rta, 1024, ILA_ATTR_LOCATOR, locator))
+	if (rta_addattr64(rta, len, ILA_ATTR_LOCATOR, locator))
 		return -1;
 
 	while (argc > 0) {
@@ -874,7 +874,7 @@ static int parse_encap_ila(struct rtattr *rta, size_t len,
 				invarg("\"csum-mode\" value is invalid\n",
 				       *argv);
 
-			ret = rta_addattr8(rta, 1024, ILA_ATTR_CSUM_MODE,
+			ret = rta_addattr8(rta, len, ILA_ATTR_CSUM_MODE,
 					   (__u8)csum_mode);
 
 			argc--; argv++;
@@ -888,7 +888,7 @@ static int parse_encap_ila(struct rtattr *rta, size_t len,
 				invarg("\"ident-type\" value is invalid\n",
 				       *argv);
 
-			ret = rta_addattr8(rta, 1024, ILA_ATTR_IDENT_TYPE,
+			ret = rta_addattr8(rta, len, ILA_ATTR_IDENT_TYPE,
 					   (__u8)ident_type);
 
 			argc--; argv++;
@@ -902,7 +902,7 @@ static int parse_encap_ila(struct rtattr *rta, size_t len,
 				invarg("\"hook-type\" value is invalid\n",
 				       *argv);
 
-			ret = rta_addattr8(rta, 1024, ILA_ATTR_HOOK_TYPE,
+			ret = rta_addattr8(rta, len, ILA_ATTR_HOOK_TYPE,
 					   (__u8)hook_type);
 
 			argc--; argv++;
@@ -1034,7 +1034,7 @@ static int parse_encap_bpf(struct rtattr *rta, size_t len, int *argcp,
 			if (get_unsigned(&headroom, *argv, 0) || headroom == 0)
 				invarg("headroom is invalid\n", *argv);
 			if (!headroom_set)
-				rta_addattr32(rta, 1024, LWT_BPF_XMIT_HEADROOM,
+				rta_addattr32(rta, len, LWT_BPF_XMIT_HEADROOM,
 					      headroom);
 			headroom_set = 1;
 		} else if (strcmp(*argv, "help") == 0) {
@@ -1075,7 +1075,7 @@ int lwt_parse_encap(struct rtattr *rta, size_t len, int *argcp, char ***argvp)
 		exit(-1);
 	}
 
-	nest = rta_nest(rta, 1024, RTA_ENCAP);
+	nest = rta_nest(rta, len, RTA_ENCAP);
 	switch (type) {
 	case LWTUNNEL_ENCAP_MPLS:
 		ret = parse_encap_mpls(rta, len, &argc, &argv);
@@ -1108,7 +1108,7 @@ int lwt_parse_encap(struct rtattr *rta, size_t len, int *argcp, char ***argvp)
 
 	rta_nest_end(rta, nest);
 
-	ret = rta_addattr16(rta, 1024, RTA_ENCAP_TYPE, type);
+	ret = rta_addattr16(rta, len, RTA_ENCAP_TYPE, type);
 
 	*argcp = argc;
 	*argvp = argv;