Patch "batman-adv: Make TT capability changes atomic" has been added to the 4.2-stable tree

Patch "batman-adv: Make TT capability changes atomic" has been added to the 4.2-stable tree

[gregkh]

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

    batman-adv: Make TT 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-tt-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@vger.kernel.org> know about it.


>From ac4eebd48461ec993e7cb614d5afe7df8c72e6b7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@c0d3.blue>
Date: Tue, 16 Jun 2015 17:10:24 +0200
Subject: batman-adv: Make TT capability changes atomic
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From: =?UTF-8?q?Linus=20L=C3=BCssing?= <linus.luessing@c0d3.blue>

commit ac4eebd48461ec993e7cb614d5afe7df8c72e6b7 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: e17931d1a61d ("batman-adv: introduce capability initialization bitfield")
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/batman-adv/translation-table.c |    8 +++++---
 net/batman-adv/types.h             |    4 ++--
 2 files changed, 7 insertions(+), 5 deletions(-)

--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -19,6 +19,7 @@
 #include "main.h"
 
 #include <linux/atomic.h>
+#include <linux/bitops.h>
 #include <linux/bug.h>
 #include <linux/byteorder/generic.h>
 #include <linux/compiler.h>
@@ -1882,7 +1883,7 @@ void batadv_tt_global_del_orig(struct ba
 		}
 		spin_unlock_bh(list_lock);
 	}
-	orig_node->capa_initialized &= ~BATADV_ORIG_CAPA_HAS_TT;
+	clear_bit(BATADV_ORIG_CAPA_HAS_TT, &orig_node->capa_initialized);
 }
 
 static bool batadv_tt_global_to_purge(struct batadv_tt_global_entry *tt_global,
@@ -2841,7 +2842,7 @@ static void _batadv_tt_update_changes(st
 				return;
 		}
 	}
-	orig_node->capa_initialized |= BATADV_ORIG_CAPA_HAS_TT;
+	set_bit(BATADV_ORIG_CAPA_HAS_TT, &orig_node->capa_initialized);
 }
 
 static void batadv_tt_fill_gtable(struct batadv_priv *bat_priv,
@@ -3343,7 +3344,8 @@ static void batadv_tt_update_orig(struct
 	bool has_tt_init;
 
 	tt_vlan = (struct batadv_tvlv_tt_vlan_data *)tt_buff;
-	has_tt_init = orig_node->capa_initialized & BATADV_ORIG_CAPA_HAS_TT;
+	has_tt_init = test_bit(BATADV_ORIG_CAPA_HAS_TT,
+			       &orig_node->capa_initialized);
 
 	/* orig table not initialised AND first diff is in the OGM OR the ttvn
 	 * increased by one -> we can apply the attached changes
--- a/net/batman-adv/types.h
+++ b/net/batman-adv/types.h
@@ -274,7 +274,7 @@ struct batadv_orig_node {
 	struct hlist_node mcast_want_all_ipv6_node;
 #endif
 	unsigned long capabilities;
-	uint8_t capa_initialized;
+	unsigned long capa_initialized;
 	atomic_t last_ttvn;
 	unsigned char *tt_buff;
 	int16_t tt_buff_len;
@@ -315,7 +315,7 @@ struct batadv_orig_node {
 enum batadv_orig_capabilities {
 	BATADV_ORIG_CAPA_HAS_DAT,
 	BATADV_ORIG_CAPA_HAS_NC,
-	BATADV_ORIG_CAPA_HAS_TT = BIT(2),
+	BATADV_ORIG_CAPA_HAS_TT,
 	BATADV_ORIG_CAPA_HAS_MCAST = BIT(3),
 };
 


Patches currently in stable-queue which might be from linus.luessing@c0d3.blue 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