Fix extension alignment

The data extensions in ipset lacked the proper memory alignment and
thus could lead to kernel crash on several architectures. Therefore
the structures have been reorganized and alignment attributes added
where needed. The patch was tested on armv7h by Gerhard Wiesinger and
on x86_64, sparc64 by Jozsef Kadlecsik.

Reported-by: Gerhard Wiesinger <lists@wiesinger.com>
Tested-by: Gerhard Wiesinger <lists@wiesinger.com>
Tested-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>

1 files changed, 4 insertions, 10 deletions

diff --git a/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c b/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c
index 64a5643..4783eff 100644
--- a/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c
+++ b/kernel/net/netfilter/ipset/ip_set_bitmap_ip.c
@@ -41,7 +41,6 @@ MODULE_ALIAS("ip_set_bitmap:ip");
 /* Type structure */
 struct bitmap_ip {
 	void *members;		/* the set members */
-	void *extensions;	/* data extensions */
 	u32 first_ip;		/* host byte order, included in range */
 	u32 last_ip;		/* host byte order, included in range */
 	u32 elements;		/* number of max elements in the set */
@@ -49,6 +48,8 @@ struct bitmap_ip {
 	size_t memsize;		/* members size */
 	u8 netmask;		/* subnet netmask */
 	struct timer_list gc;	/* garbage collection */
+	unsigned char extensions[0]	/* data extensions */
+		__aligned(__alignof__(u64));
 };
 
 /* ADT structure for generic function args */
@@ -224,13 +225,6 @@ init_map_ip(struct ip_set *set, struct bitmap_ip *map,
 	map->members = ip_set_alloc(map->memsize);
 	if (!map->members)
 		return false;
-	if (set->dsize) {
-		map->extensions = ip_set_alloc(set->dsize * elements);
-		if (!map->extensions) {
-			kfree(map->members);
-			return false;
-		}
-	}
 	map->first_ip = first_ip;
 	map->last_ip = last_ip;
 	map->elements = elements;
@@ -316,13 +310,13 @@ bitmap_ip_create(struct net *net, struct ip_set *set, struct nlattr *tb[],
 	pr_debug("hosts %u, elements %llu\n",
 		 hosts, (unsigned long long)elements);
 
-	map = kzalloc(sizeof(*map), GFP_KERNEL);
+	set->dsize = ip_set_elem_len(set, tb, 0, 0);
+	map = ip_set_alloc(sizeof(*map) + elements * set->dsize);
 	if (!map)
 		return -ENOMEM;
 
 	map->memsize = bitmap_bytes(0, elements - 1);
 	set->variant = &bitmap_ip;
-	set->dsize = ip_set_elem_len(set, tb, 0);
 	if (!init_map_ip(set, map, first_ip, last_ip,
 			 elements, hosts, netmask)) {
 		kfree(map);