From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: Subject: Patch "slub: Do not hold slub_lock when calling sysfs_slab_add()" has been added to the 3.0-stable tree To: cl@linux.com,eric.dumazet@gmail.com,gregkh@linuxfoundation.org,levinsasha928@gmail.com,penberg@kernel.org Cc: , From: Date: Thu, 29 Mar 2012 09:03:20 -0700 Message-ID: <1333037000902@kroah.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ASCII Content-Transfer-Encoding: 8bit List-ID: This is a note to let you know that I've just added the patch titled slub: Do not hold slub_lock when calling sysfs_slab_add() to the 3.0-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: slub-do-not-hold-slub_lock-when-calling-sysfs_slab_add.patch and it can be found in the queue-3.0 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 66c4c35c6bc5a1a452b024cf0364635b28fd94e4 Mon Sep 17 00:00:00 2001 From: Christoph Lameter Date: Tue, 17 Jan 2012 09:27:31 -0600 Subject: slub: Do not hold slub_lock when calling sysfs_slab_add() From: Christoph Lameter commit 66c4c35c6bc5a1a452b024cf0364635b28fd94e4 upstream. sysfs_slab_add() calls various sysfs functions that actually may end up in userspace doing all sorts of things. Release the slub_lock after adding the kmem_cache structure to the list. At that point the address of the kmem_cache is not known so we are guaranteed exlusive access to the following modifications to the kmem_cache structure. If the sysfs_slab_add fails then reacquire the slub_lock to remove the kmem_cache structure from the list. Reported-by: Sasha Levin Acked-by: Eric Dumazet Signed-off-by: Christoph Lameter Signed-off-by: Pekka Enberg Signed-off-by: Greg Kroah-Hartman --- mm/slub.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/slub.c +++ b/mm/slub.c @@ -3439,13 +3439,14 @@ struct kmem_cache *kmem_cache_create(con if (kmem_cache_open(s, n, size, align, flags, ctor)) { list_add(&s->list, &slab_caches); + up_write(&slub_lock); if (sysfs_slab_add(s)) { + down_write(&slub_lock); list_del(&s->list); kfree(n); kfree(s); goto err; } - up_write(&slub_lock); return s; } kfree(n); Patches currently in stable-queue which might be from cl@linux.com are queue-3.0/slub-do-not-hold-slub_lock-when-calling-sysfs_slab_add.patch