Patch "ipv6: release dst in ping_v6_sendmsg" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    ipv6: release dst in ping_v6_sendmsg

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-release-dst-in-ping_v6_sendmsg.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 Wed Sep 21 12:45:10 CEST 2016
From: Dave Jones <davej@codemonkey.org.uk>
Date: Fri, 2 Sep 2016 14:39:50 -0400
Subject: ipv6: release dst in ping_v6_sendmsg

From: Dave Jones <davej@codemonkey.org.uk>


[ Upstream commit 03c2778a938aaba0893f6d6cdc29511d91a79848 ]

Neither the failure or success paths of ping_v6_sendmsg release
the dst it acquires.  This leads to a flood of warnings from
"net/core/dst.c:288 dst_release" on older kernels that
don't have 8bf4ada2e21378816b28205427ee6b0e1ca4c5f1 backported.

That patch optimistically hoped this had been fixed post 3.10, but
it seems at least one case wasn't, where I've seen this triggered
a lot from machines doing unprivileged icmp sockets.

Cc: Martin Lau <kafai@fb.com>
Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
---
 net/ipv6/ping.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

--- a/net/ipv6/ping.c
+++ b/net/ipv6/ping.c
@@ -150,8 +150,10 @@ int ping_v6_sendmsg(struct sock *sk, str
 	rt = (struct rt6_info *) dst;
 
 	np = inet6_sk(sk);
-	if (!np)
-		return -EBADF;
+	if (!np) {
+		err = -EBADF;
+		goto dst_err_out;
+	}
 
 	if (!fl6.flowi6_oif && ipv6_addr_is_multicast(&fl6.daddr))
 		fl6.flowi6_oif = np->mcast_oif;
@@ -186,6 +188,9 @@ int ping_v6_sendmsg(struct sock *sk, str
 	}
 	release_sock(sk);
 
+dst_err_out:
+	dst_release(dst);
+
 	if (err)
 		return err;
 


Patches currently in stable-queue which might be from davej@codemonkey.org.uk are

queue-4.4/ipv6-release-dst-in-ping_v6_sendmsg.patch