From 9528f6656f459de10fc0c036932804d9eddcf8e5 Mon Sep 17 00:00:00 2001 From: Steffen Klassert Date: Wed, 1 Aug 2018 13:45:11 +0200 Subject: [PATCH] xfrm: Validate address prefix lengths in the xfrm selector. commit 07bf7908950a8b14e81aa1807e3c667eab39287a upstream. We don't validate the address prefix lengths in the xfrm selector we got from userspace. This can lead to undefined behaviour in the address matching functions if the prefix is too big for the given address family. Fix this by checking the prefixes and refuse SA/policy insertation when a prefix is invalid. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Air Icy Signed-off-by: Steffen Klassert Signed-off-by: Ben Hutchings --- net/xfrm/xfrm_user.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 25dc962431d4..62fbbdc58566 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -150,10 +150,16 @@ static int verify_newsa_info(struct xfrm_usersa_info *p, err = -EINVAL; switch (p->family) { case AF_INET: + if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32) + goto out; + break; case AF_INET6: #if IS_ENABLED(CONFIG_IPV6) + if (p->sel.prefixlen_d > 128 || p->sel.prefixlen_s > 128) + goto out; + break; #else err = -EAFNOSUPPORT; @@ -1227,10 +1233,16 @@ static int verify_newpolicy_info(struct xfrm_userpolicy_info *p) switch (p->sel.family) { case AF_INET: + if (p->sel.prefixlen_d > 32 || p->sel.prefixlen_s > 32) + return -EINVAL; + break; case AF_INET6: #if IS_ENABLED(CONFIG_IPV6) + if (p->sel.prefixlen_d > 128 || p->sel.prefixlen_s > 128) + return -EINVAL; + break; #else return -EAFNOSUPPORT;