[patch 03/31] Fix user copy length in ipv6_sockglue.c

[Greg KH]

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

------------------

From: Chris Wright <chrisw@xxxxxxxxxxxx>

[IPV6] fix ipv6_getsockopt_sticky copy_to_user leak

User supplied len < 0 can cause leak of kernel memory.
Use unsigned compare instead.

Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
 net/ipv6/ipv6_sockglue.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -805,7 +805,7 @@ static int ipv6_getsockopt_sticky(struct
 		return 0;
 	hdr = opt->hopopt;
 
-	len = min_t(int, len, ipv6_optlen(hdr));
+	len = min_t(unsigned int, len, ipv6_optlen(hdr));
 	if (copy_to_user(optval, hdr, ipv6_optlen(hdr)))
 		return -EFAULT;
 	return len;

-- 
-
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