diff options
Diffstat (limited to 'lib/nlattr.c')
| -rw-r--r-- | lib/nlattr.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c index 3d8295c85505..dfa55c873c13 100644 --- 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]); } |