From 61ec3a5696f0c32448c93b713f934b007b85f961 Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Thu, 3 Nov 2011 00:07:32 +0000 Subject: netlink: validate NLA_MSECS length commit c30bc94758ae2a38a5eb31767c1985c0aae0950b upstream. L2TP for example uses NLA_MSECS like this: policy: [L2TP_ATTR_RECV_TIMEOUT] = { .type = NLA_MSECS, }, code: if (info->attrs[L2TP_ATTR_RECV_TIMEOUT]) cfg.reorder_timeout = nla_get_msecs(info->attrs[L2TP_ATTR_RECV_TIMEOUT]); As nla_get_msecs() is essentially nla_get_u64() plus the conversion to a HZ-based value, this will not properly reject attributes from userspace that aren't long enough and might overrun the message. Add NLA_MSECS to the attribute minlen array to check the size properly. Cc: Thomas Graf Signed-off-by: Johannes Berg Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- lib/nlattr.c | 1 + 1 file changed, 1 insertion(+) diff --git a/lib/nlattr.c b/lib/nlattr.c index ac09f2226dc7..a8408b6cacdf 100644 --- a/lib/nlattr.c +++ b/lib/nlattr.c @@ -20,6 +20,7 @@ static const u16 nla_attr_minlen[NLA_TYPE_MAX+1] = { [NLA_U16] = sizeof(u16), [NLA_U32] = sizeof(u32), [NLA_U64] = sizeof(u64), + [NLA_MSECS] = sizeof(u64), [NLA_NESTED] = NLA_HDRLEN, }; -- cgit v1.2.3