This is a note to let you know that I've just added the patch titled
batman-adv: Make MCAST capability changes atomic
to the 4.2-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:
batman-adv-make-mcast-capability-changes-atomic.patch
and it can be found in the queue-4.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 9c936e3f4c4fad07abb6c082a89508b8f724c88f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@xxxxxxxxx>
Date: Tue, 16 Jun 2015 17:10:25 +0200
Subject: batman-adv: Make MCAST capability changes atomic
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@xxxxxxxxx>
commit 9c936e3f4c4fad07abb6c082a89508b8f724c88f upstream.
Bitwise OR/AND assignments in C aren't guaranteed to be atomic. One
OGM handler might undo the set/clear of a specific bit from another
handler run in between.
Fix this by using the atomic set_bit()/clear_bit()/test_bit() functions.
Fixes: 60432d756cf0 ("batman-adv: Announce new capability via multicast TVLV")
Signed-off-by: Linus Lüssing <linus.luessing@xxxxxxxxx>
Signed-off-by: Marek Lindner <mareklindner@xxxxxxxxxxxxx>
Signed-off-by: Antonio Quartulli <antonio@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/batman-adv/multicast.c | 18 ++++++++++--------
net/batman-adv/types.h | 2 +-
2 files changed, 11 insertions(+), 9 deletions(-)
--- a/net/batman-adv/multicast.c
+++ b/net/batman-adv/multicast.c
@@ -19,6 +19,7 @@
#include "main.h"
#include <linux/atomic.h>
+#include <linux/bitops.h>
#include <linux/byteorder/generic.h>
#include <linux/errno.h>
#include <linux/etherdevice.h>
@@ -697,29 +698,30 @@ static void batadv_mcast_tvlv_ogm_handle
uint8_t mcast_flags = BATADV_NO_FLAGS;
bool orig_initialized;
- orig_initialized = orig->capa_initialized & BATADV_ORIG_CAPA_HAS_MCAST;
+ orig_initialized = test_bit(BATADV_ORIG_CAPA_HAS_MCAST,
+ &orig->capa_initialized);
/* If mcast support is turned on decrease the disabled mcast node
* counter only if we had increased it for this node before. If this
* is a completely new orig_node no need to decrease the counter.
*/
if (orig_mcast_enabled &&
- !(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST)) {
+ !test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities)) {
if (orig_initialized)
atomic_dec(&bat_priv->mcast.num_disabled);
- orig->capabilities |= BATADV_ORIG_CAPA_HAS_MCAST;
+ set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
/* If mcast support is being switched off or if this is an initial
* OGM without mcast support then increase the disabled mcast
* node counter.
*/
} else if (!orig_mcast_enabled &&
- (orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST ||
+ (test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) ||
!orig_initialized)) {
atomic_inc(&bat_priv->mcast.num_disabled);
- orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_MCAST;
+ clear_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities);
}
- orig->capa_initialized |= BATADV_ORIG_CAPA_HAS_MCAST;
+ set_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized);
if (orig_mcast_enabled && tvlv_value &&
(tvlv_value_len >= sizeof(mcast_flags)))
@@ -763,8 +765,8 @@ void batadv_mcast_purge_orig(struct bata
{
struct batadv_priv *bat_priv = orig->bat_priv;
- if (!(orig->capabilities & BATADV_ORIG_CAPA_HAS_MCAST) &&
- orig->capa_initialized & BATADV_ORIG_CAPA_HAS_MCAST)
+ if (!test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capabilities) &&
+ test_bit(BATADV_ORIG_CAPA_HAS_MCAST, &orig->capa_initialized))
atomic_dec(&bat_priv->mcast.num_disabled);
batadv_mcast_want_unsnoop_update(bat_priv, orig, BATADV_NO_FLAGS);
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -316,7 +316,7 @@ enum batadv_orig_capabilities {
BATADV_ORIG_CAPA_HAS_DAT,
BATADV_ORIG_CAPA_HAS_NC,
BATADV_ORIG_CAPA_HAS_TT,
- BATADV_ORIG_CAPA_HAS_MCAST = BIT(3),
+ BATADV_ORIG_CAPA_HAS_MCAST,
};
/**
Patches currently in stable-queue which might be from linus.luessing@xxxxxxxxx are
queue-4.2/batman-adv-fix-potential-synchronization-issues-in-mcast-tvlv-handler.patch
queue-4.2/batman-adv-make-tt-capability-changes-atomic.patch
queue-4.2/batman-adv-make-dat-capability-changes-atomic.patch
queue-4.2/batman-adv-make-nc-capability-changes-atomic.patch
queue-4.2/batman-adv-fix-potentially-broken-skb-network-header-access.patch
queue-4.2/batman-adv-make-mcast-capability-changes-atomic.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html