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| author | David Ahern <dsahern@gmail.com> | 2017-11-07 21:59:40 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-11-11 15:14:38 +0900 |
| commit | 28033ae4e0f59782b3f3357d9c28852a7e84a894 (patch) | |
| tree | 28b50e6aced09e14ff02b907745ec511d2ee8790 /lib/nlattr.c | |
| parent | 2210d6b2f287d738eddf6b75f432126ce05450f8 (diff) | |
| download | lwn-28033ae4e0f59782b3f3357d9c28852a7e84a894.tar.gz lwn-28033ae4e0f59782b3f3357d9c28852a7e84a894.zip | |
net: netlink: Update attr validation to require exact length for some types
Attributes using NLA_U* and NLA_S* (where * is 8, 16,32 and 64) are
expected to be an exact length. Split these data types from
nla_attr_minlen into nla_attr_len and update validate_nla to require
the attribute to have exact length for them.
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib/nlattr.c')
| -rw-r--r-- | lib/nlattr.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/lib/nlattr.c b/lib/nlattr.c index 3d8295c85505..8bf78b4b78f0 100644 --- 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]); } |