afs: cell: Remove unnecessary code in afs_lookup_cell

[mirror_ubuntu-bionic-kernel.git] / lib / nlattr.c

diff --git a/lib/nlattr.c b/lib/nlattr.c
index 3d8295c8550532cea0a6a50409deed23c8a2026b..8bf78b4b78f0a286e40941344ecd4b504738cc01 100644 (file)
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -15,19 +15,23 @@
 #include <linux/types.h>
 #include <net/netlink.h>
 
-static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
+/* for these data types attribute length must be exactly given size */
+static const u8 nla_attr_len[NLA_TYPE_MAX+1] = {
        [NLA_U8]        = sizeof(u8),
        [NLA_U16]       = sizeof(u16),
        [NLA_U32]       = sizeof(u32),
        [NLA_U64]       = sizeof(u64),
-       [NLA_MSECS]     = sizeof(u64),
-       [NLA_NESTED]    = NLA_HDRLEN,
        [NLA_S8]        = sizeof(s8),
        [NLA_S16]       = sizeof(s16),
        [NLA_S32]       = sizeof(s32),
        [NLA_S64]       = sizeof(s64),
 };
 
+static const u8 nla_attr_minlen[NLA_TYPE_MAX+1] = {
+       [NLA_MSECS]     = sizeof(u64),
+       [NLA_NESTED]    = NLA_HDRLEN,
+};
+
 static int validate_nla_bitfield32(const struct nlattr *nla,
                                   u32 *valid_flags_allowed)
 {
@@ -65,6 +69,13 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
 
        BUG_ON(pt->type > NLA_TYPE_MAX);
 
+       /* for data types NLA_U* and NLA_S* require exact length */
+       if (nla_attr_len[pt->type]) {
+               if (attrlen != nla_attr_len[pt->type])
+                       return -ERANGE;
+               return 0;
+       }
+
        switch (pt->type) {
        case NLA_FLAG:
                if (attrlen > 0)
@@ -191,6 +202,8 @@ nla_policy_len(const struct nla_policy *p, int n)
        for (i = 0; i < n; i++, p++) {
                if (p->len)
                        len += nla_total_size(p->len);
+               else if (nla_attr_len[p->type])
+                       len += nla_total_size(nla_attr_len[p->type]);
                else if (nla_attr_minlen[p->type])
                        len += nla_total_size(nla_attr_minlen[p->type]);
        }