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

    batman-adv: Make DAT 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-dat-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 <[email protected]> know about it.


>From 65d7d46050704bcdb8121ddbf4110bfbf2b38baa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Linus=20L=C3=BCssing?= <[email protected]>
Date: Tue, 16 Jun 2015 17:10:22 +0200
Subject: batman-adv: Make DAT 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?= <[email protected]>

commit 65d7d46050704bcdb8121ddbf4110bfbf2b38baa 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: 17cf0ea455f1 ("batman-adv: tvlv - add distributed arp table container")
Signed-off-by: Linus Lüssing <[email protected]>
Signed-off-by: Marek Lindner <[email protected]>
Signed-off-by: Antonio Quartulli <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 net/batman-adv/distributed-arp-table.c |    7 ++++---
 net/batman-adv/types.h                 |    4 ++--
 2 files changed, 6 insertions(+), 5 deletions(-)

--- a/net/batman-adv/distributed-arp-table.c
+++ b/net/batman-adv/distributed-arp-table.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>
@@ -453,7 +454,7 @@ static bool batadv_is_orig_node_eligible
        int j;
 
        /* check if orig node candidate is running DAT */
-       if (!(candidate->capabilities & BATADV_ORIG_CAPA_HAS_DAT))
+       if (!test_bit(BATADV_ORIG_CAPA_HAS_DAT, &candidate->capabilities))
                goto out;
 
        /* Check if this node has already been selected... */
@@ -713,9 +714,9 @@ static void batadv_dat_tvlv_ogm_handler_
                                           uint16_t tvlv_value_len)
 {
        if (flags & BATADV_TVLV_HANDLER_OGM_CIFNOTFND)
-               orig->capabilities &= ~BATADV_ORIG_CAPA_HAS_DAT;
+               clear_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
        else
-               orig->capabilities |= BATADV_ORIG_CAPA_HAS_DAT;
+               set_bit(BATADV_ORIG_CAPA_HAS_DAT, &orig->capabilities);
 }
 
 /**
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -273,7 +273,7 @@ struct batadv_orig_node {
        struct hlist_node mcast_want_all_ipv4_node;
        struct hlist_node mcast_want_all_ipv6_node;
 #endif
-       uint8_t capabilities;
+       unsigned long capabilities;
        uint8_t capa_initialized;
        atomic_t last_ttvn;
        unsigned char *tt_buff;
@@ -313,7 +313,7 @@ struct batadv_orig_node {
  *  (= orig node announces a tvlv of type BATADV_TVLV_MCAST)
  */
 enum batadv_orig_capabilities {
-       BATADV_ORIG_CAPA_HAS_DAT = BIT(0),
+       BATADV_ORIG_CAPA_HAS_DAT,
        BATADV_ORIG_CAPA_HAS_NC = BIT(1),
        BATADV_ORIG_CAPA_HAS_TT = BIT(2),
        BATADV_ORIG_CAPA_HAS_MCAST = BIT(3),


Patches currently in stable-queue which might be from [email protected] 
are

queue-4.2/batman-adv-make-dat-capability-changes-atomic.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to