Partially revert "kfifo: fix kfifo_alloc() and kfifo_init()"

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

diff --git a/lib/nlattr.c b/lib/nlattr.c
index 3d8295c8550532cea0a6a50409deed23c8a2026b..dfa55c873c1318643fdbcbe916b9c18a54edc4c9 100644 (file)
--- a/lib/nlattr.c
+++ b/lib/nlattr.c
@@ -15,6 +15,22 @@
 #include <linux/types.h>
 #include <net/netlink.h>
 
+/* For these data types, attribute length should be exactly the given
+ * size. However, to maintain compatibility with broken commands, if the
+ * attribute length does not match the expected size a warning is emitted
+ * to the user that the command is sending invalid data and needs to be fixed.
+ */
+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_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_U8]        = sizeof(u8),
        [NLA_U16]       = sizeof(u16),
@@ -65,6 +81,11 @@ static int validate_nla(const struct nlattr *nla, int maxtype,
 
        BUG_ON(pt->type > NLA_TYPE_MAX);
 
+       if (nla_attr_len[pt->type] && attrlen != nla_attr_len[pt->type]) {
+               pr_warn_ratelimited("netlink: '%s': attribute type %d has an invalid length.\n",
+                                   current->comm, type);
+       }
+
        switch (pt->type) {
        case NLA_FLAG:
                if (attrlen > 0)
@@ -191,6 +212,8 @@ 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]);
        }