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

    cgroup: fix an off-by-one bug which may trigger BUG_ON()

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:
     cgroup-fix-an-off-by-one-bug-which-may-trigger-bug_on.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 <[email protected]> know about it.


>From 3ac1707a13a3da9cfc8f242a15b2fae6df2c5f88 Mon Sep 17 00:00:00 2001
From: Li Zefan <[email protected]>
Date: Tue, 12 Mar 2013 15:36:00 -0700
Subject: cgroup: fix an off-by-one bug which may trigger BUG_ON()

From: Li Zefan <[email protected]>

commit 3ac1707a13a3da9cfc8f242a15b2fae6df2c5f88 upstream.

The 3rd parameter of flex_array_prealloc() is the number of elements,
not the index of the last element.

The effect of the bug is, when opening cgroup.procs, a flex array will
be allocated and all elements of the array is allocated with
GFP_KERNEL flag, but the last one is GFP_ATOMIC, and if we fail to
allocate memory for it, it'll trigger a BUG_ON().

Signed-off-by: Li Zefan <[email protected]>
Signed-off-by: Tejun Heo <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

---
 kernel/cgroup.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2026,7 +2026,7 @@ int cgroup_attach_proc(struct cgroup *cg
        if (!group)
                return -ENOMEM;
        /* pre-allocate to guarantee space while iterating in rcu read-side. */
-       retval = flex_array_prealloc(group, 0, group_size - 1, GFP_KERNEL);
+       retval = flex_array_prealloc(group, 0, group_size, GFP_KERNEL);
        if (retval)
                goto out_free_group_list;
 


Patches currently in stable-queue which might be from [email protected] are

queue-3.0/cgroup-fix-an-off-by-one-bug-which-may-trigger-bug_on.patch
queue-3.0/fs-fscache-stats.c-fix-memory-leak.patch
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