[3.11.y.z extended stable] Patch "nl80211: Reset split_start when netlink skb is exhausted" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    nl80211: Reset split_start when netlink skb is exhausted

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From b5179c214a3a078329d093a28d40f723cc9b1c29 Mon Sep 17 00:00:00 2001
From: Pontus Fuchs <pontus.fuchs at gmail.com>
Date: Thu, 16 Jan 2014 15:00:40 +0100
Subject: nl80211: Reset split_start when netlink skb is exhausted

commit f12cb2893069495726c21a4b0178705dacfecfe0 upstream.

When the netlink skb is exhausted split_start is left set. In the
subsequent retry, with a larger buffer, the dump is continued from the
failing point instead of from the beginning.

This was causing my rt28xx based USB dongle to now show up when
running "iw list" with an old iw version without split dump support.

Fixes: 3713b4e364ef ("nl80211: allow splitting wiphy information in dumps")
Signed-off-by: Pontus Fuchs <pontus.fuchs at gmail.com>
[avoid the entire workaround when state->split is set]
Signed-off-by: Johannes Berg <johannes.berg at intel.com>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/wireless/nl80211.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 7956f41..95b8565 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -1613,9 +1613,10 @@ static int nl80211_dump_wiphy(struct sk_buff *skb, struct netlink_callback *cb)
 				 * We can then retry with the larger buffer.
 				 */
 				if ((ret == -ENOBUFS || ret == -EMSGSIZE) &&
-				    !skb->len &&
+				    !skb->len && !state->split &&
 				    cb->min_dump_alloc < 4096) {
 					cb->min_dump_alloc = 4096;
+					state->split_start = 0;
 					rtnl_unlock();
 					return 1;
 				}
--
1.9.0