[patch 03/10] sctp: Make sure N * sizeof(union sctp_addr) does not overflow.

[Greg KH <gregkh@suse.de>]

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2.6.25.9-stable review patch.  If anyone has any objections, please let
us know.

------------------ 
From: David S. Miller <davem@davemloft.net>

commit 735ce972fbc8a65fb17788debd7bbe7b4383cc62 upstream

As noticed by Gabriel Campana, the kmalloc() length arg
passed in by sctp_getsockopt_local_addrs_old() can overflow
if ->addr_num is large enough.

Therefore, enforce an appropriate limit.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 net/sctp/socket.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -4421,7 +4421,9 @@ static int sctp_getsockopt_local_addrs_o
 	if (copy_from_user(&getaddrs, optval, len))
 		return -EFAULT;
 
-	if (getaddrs.addr_num <= 0) return -EINVAL;
+	if (getaddrs.addr_num <= 0 ||
+	    getaddrs.addr_num >= (INT_MAX / sizeof(union sctp_addr)))
+		return -EINVAL;
 	/*
 	 *  For UDP-style sockets, id specifies the association to query.
 	 *  If the id field is set to the value '0' then the locally bound

--