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>

1 files changed, 3 insertions, 1 deletions

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;