linux-kernel - [PATCH] slab: initialize unused alien cache entry as NULL at alloc_alien

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 22 Dec 2009 20:38:00 +0800
From:	Haicheng Li <haicheng.li@...ux.intel.com>
To:	linux-mm@...ck.org, Christoph Lameter <cl@...ux-foundation.org>,
	Pekka Enberg <penberg@...helsinki.fi>,
	Matt Mackall <mpm@...enic.com>, andi@...stfloor.org,
	linux-kernel@...r.kernel.org
Subject: [PATCH] slab: initialize unused alien cache entry as NULL at alloc_alien_cache().

Memory hotplug would online new node in runtime, then reap timer will add this new node as 
a reap node. In such case, for each existing kmem_list, we need to ensure that the alien 
cache entry corresponding to this new added node is NULL. Otherwise, it might cause BUG 
when reap_alien() affecting the new added node.

Signed-off-by: Haicheng Li <haicheng.li@...ux.intel.com>
---
  mm/slab.c |    7 +++----
  1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/slab.c b/mm/slab.c
index 7dfa481..a9486a0 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -966,18 +966,17 @@ static void *alternate_node_alloc(struct kmem_cache *, gfp_t);
  static struct array_cache **alloc_alien_cache(int node, int limit, gfp_t gfp)
  {
  	struct array_cache **ac_ptr;
-	int memsize = sizeof(void *) * nr_node_ids;
+	int memsize = sizeof(void *) * MAX_NUMNODES;
  	int i;

  	if (limit > 1)
  		limit = 12;
  	ac_ptr = kmalloc_node(memsize, gfp, node);
  	if (ac_ptr) {
+		memset(ac_ptr, 0, memsize);
  		for_each_node(i) {
-			if (i == node || !node_online(i)) {
-				ac_ptr[i] = NULL;
+			if (i == node || !node_online(i))
  				continue;
-			}
  			ac_ptr[i] = alloc_arraycache(node, limit, 0xbaadf00d, gfp);
  			if (!ac_ptr[i]) {
  				for (i--; i >= 0; i--)
-- 
1.6.0.rc1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/