Patch "ipv6: check raw payload size correctly in ioctl" has been added to the 4.4-stable tree

Patch "ipv6: check raw payload size correctly in ioctl" has been added to the 4.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ipv6: check raw payload size correctly in ioctl

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ipv6-check-raw-payload-size-correctly-in-ioctl.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sun Apr 30 15:46:17 CEST 2017
From: Jamie Bainbridge <jbainbri@redhat.com>
Date: Wed, 26 Apr 2017 10:43:27 +1000
Subject: ipv6: check raw payload size correctly in ioctl

From: Jamie Bainbridge <jbainbri@redhat.com>


[ Upstream commit 105f5528b9bbaa08b526d3405a5bcd2ff0c953c8 ]

In situations where an skb is paged, the transport header pointer and
tail pointer can be the same because the skb contents are in frags.

This results in ioctl(SIOCINQ/FIONREAD) incorrectly returning a
length of 0 when the length to receive is actually greater than zero.

skb->len is already correctly set in ip6_input_finish() with
pskb_pull(), so use skb->len as it always returns the correct result
for both linear and paged data.

Signed-off-by: Jamie Bainbridge <jbainbri@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv6/raw.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

--- a/net/ipv6/raw.c
+++ b/net/ipv6/raw.c
@@ -1144,8 +1144,7 @@ static int rawv6_ioctl(struct sock *sk,
 		spin_lock_bh(&sk->sk_receive_queue.lock);
 		skb = skb_peek(&sk->sk_receive_queue);
 		if (skb)
-			amount = skb_tail_pointer(skb) -
-				skb_transport_header(skb);
+			amount = skb->len;
 		spin_unlock_bh(&sk->sk_receive_queue.lock);
 		return put_user(amount, (int __user *)arg);
 	}


Patches currently in stable-queue which might be from jbainbri@redhat.com are

queue-4.4/ipv6-check-raw-payload-size-correctly-in-ioctl.patch