From c30bc94758ae2a38a5eb31767c1985c0aae0950b Mon Sep 17 00:00:00 2001
From: Johannes Berg <johannes.berg@intel.com>
Date: Thu, 3 Nov 2011 00:07:32 +0000
Subject: [PATCH] netlink: validate NLA_MSECS length
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 <tgraf@suug.ch>
Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
lib/nlattr.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/lib/nlattr.c b/lib/nlattr.c
index ac09f2226dc74..a8408b6cacdf7 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,
};
--
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