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Patch "batman-adv: Make DAT capability changes atomic" has been added to the 4.1-stable tree

PATCH [email protected] 1 participant 1 message Oct 17, 2015

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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 4.1-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-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

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
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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(-)
net/batman-adv/distributed-arp-table.c +4 -3
@@ -15,6 +15,7 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/bitops.h>
 #include <linux/if_ether.h>
 #include <linux/if_arp.h>
 #include <linux/if_vlan.h>

@@ -422,7 +423,7 @@ 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... */

@@ -682,9 +683,9 @@ 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);
 }
 
 /**
net/batman-adv/types.h +2 -2
@@ -256,7 +256,7 @@ 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;

@@ -296,7 +296,7 @@ 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-4.1/batman-adv-make-dat-capability-changes-atomic.patch