From fa6dd8a2c89861d05621ce7e2880e485bec22fba Mon Sep 17 00:00:00 2001
From: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Date: Tue, 11 Jan 2011 08:04:12 +0000
Subject: [PATCH] xfrm: check trunc_len in XFRMA_ALG_AUTH_TRUNC

Maximum trunc length is defined by MAX_AH_AUTH_LEN (in bytes)
and need to be checked when this value is set (in bits) by
the user. In ah4.c and ah6.c a BUG_ON() checks this condiftion.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/xfrm/xfrm_user.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index 6a8da81ff66f..d5e1e0b08890 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -26,6 +26,7 @@
 #include <net/sock.h>
 #include <net/xfrm.h>
 #include <net/netlink.h>
+#include <net/ah.h>
 #include <asm/uaccess.h>
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 #include <linux/in6.h>
@@ -302,7 +303,8 @@ static int attach_auth_trunc(struct xfrm_algo_auth **algpp, u8 *props,
 	algo = xfrm_aalg_get_byname(ualg->alg_name, 1);
 	if (!algo)
 		return -ENOSYS;
-	if (ualg->alg_trunc_len > algo->uinfo.auth.icv_fullbits)
+	if ((ualg->alg_trunc_len / 8) > MAX_AH_AUTH_LEN ||
+	    ualg->alg_trunc_len > algo->uinfo.auth.icv_fullbits)
 		return -EINVAL;
 	*props = algo->desc.sadb_alg_id;
 
-- 
2.39.2