From 6307208c806f9b968eca178931b3d77c4ed83c54 Mon Sep 17 00:00:00 2001

From: Petr Mensik <pemensik@redhat.com>

Date: Fri, 6 Mar 2020 15:37:23 +0100

Subject: [PATCH] Correct range check of dhcp-host prefix

It incorrectly works with 32 bit integer only when counting number of

addresses in range. It works correctly only between prefixlen 96 and

128. Use 64bit shift to work with well with numbers higher than 64.

Fixes commit 79aba0f10ad0157fb4f48afbbcb03f094caff97a error.

---

 src/option.c  | 2 +-

 src/rfc3315.c | 2 +-

 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/option.c b/src/option.c

index 88cd2ab..79122df 100644

--- a/src/option.c

+++ b/src/option.c

@@ -3247,7 +3247,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma

 			if (!atoi_check(pref, &new_addr->prefixlen) ||

 			    new_addr->prefixlen > 128 ||

-			    (((1<<(128-new_addr->prefixlen))-1) & addrpart) != 0)

+			    ((((u64)1<<(128-new_addr->prefixlen))-1) & addrpart) != 0)

 			  {

 			    dhcp_config_free(new);

 			    ret_err(_("bad IPv6 prefix"));

diff --git a/src/rfc3315.c b/src/rfc3315.c

index a0067e9..f59aedc 100644

--- a/src/rfc3315.c

+++ b/src/rfc3315.c

@@ -1798,7 +1798,7 @@ static int config_valid(struct dhcp_config *config, struct dhcp_context *context

       addresses = 1;

       if (addr_list->flags & ADDRLIST_PREFIX)

-	addresses = 1<<(128-addr_list->prefixlen);

+	addresses = (u64)1<<(128-addr_list->prefixlen);

       if ((addr_list->flags & ADDRLIST_WILDCARD))

 	{

-- 

2.21.1