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* [PATCH] Fix getsockopt(SO_PEERNAME) buffer size against potential future buffer overflow
@ 2014-09-28 13:55 Samuel Thibault
  2014-09-30  4:59 ` David Miller
  0 siblings, 1 reply; 2+ messages in thread
From: Samuel Thibault @ 2014-09-28 13:55 UTC (permalink / raw)
  To: linux-kernel, davem, netdev; +Cc: akpm

In net/core/sock.c's sock_getsockopt, the address buffer size is
hardcoded to 128. It happens that sizeof(struct sockaddr_storage) is
indeed 128, but that is just luck and would probably not get updated
whenever sockaddr_storage would grow. This patch makes it simply use
sockaddr_storage instead.

Signed-off-by:  Samuel Thibault <samuel.thibault@ens-lyon.org>

--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1155,13 +1155,13 @@ int sock_getsockopt(struct socket *sock,
 
 	case SO_PEERNAME:
 	{
-		char address[128];
+		struct sockaddr_storage address;
 
-		if (sock->ops->getname(sock, (struct sockaddr *)address, &lv, 2))
+		if (sock->ops->getname(sock, (struct sockaddr *)&address, &lv, 2))
 			return -ENOTCONN;
 		if (lv < len)
 			return -EINVAL;
-		if (copy_to_user(optval, address, len))
+		if (copy_to_user(optval, &address, len))
 			return -EFAULT;
 		goto lenout;
 	}

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] Fix getsockopt(SO_PEERNAME) buffer size against potential future buffer overflow
  2014-09-28 13:55 [PATCH] Fix getsockopt(SO_PEERNAME) buffer size against potential future buffer overflow Samuel Thibault
@ 2014-09-30  4:59 ` David Miller
  0 siblings, 0 replies; 2+ messages in thread
From: David Miller @ 2014-09-30  4:59 UTC (permalink / raw)
  To: samuel.thibault; +Cc: linux-kernel, netdev, akpm

From: Samuel Thibault <samuel.thibault@ens-lyon.org>
Date: Sun, 28 Sep 2014 15:55:45 +0200

> In net/core/sock.c's sock_getsockopt, the address buffer size is
> hardcoded to 128. It happens that sizeof(struct sockaddr_storage) is
> indeed 128, but that is just luck and would probably not get updated
> whenever sockaddr_storage would grow. This patch makes it simply use
> sockaddr_storage instead.
> 
> Signed-off-by:  Samuel Thibault <samuel.thibault@ens-lyon.org>

sockaddr_storage's size is a user exported API and therefore can
never, ever, change.

If you want to change 128 to _K_SS_MAXSIZE or similar, fine.

^ permalink raw reply	[flat|nested] 2+ messages in thread

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2014-09-28 13:55 [PATCH] Fix getsockopt(SO_PEERNAME) buffer size against potential future buffer overflow Samuel Thibault
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