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 3.8-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-3.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3ac1707a13a3da9cfc8f242a15b2fae6df2c5f88 Mon Sep 17 00:00:00 2001
From: Li Zefan <lizefan@xxxxxxxxxx>
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 <lizefan@xxxxxxxxxx>
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 <lizefan@xxxxxxxxxx>
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/cgroup.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -2066,7 +2066,7 @@ static int cgroup_attach_proc(struct cgr
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 lizefan@xxxxxxxxxx are
queue-3.8/cgroup-fix-an-off-by-one-bug-which-may-trigger-bug_on.patch
queue-3.8/exec-do-not-abuse-cred_guard_mutex-in-threadgroup_lock.patch
queue-3.8/fs-fscache-stats.c-fix-memory-leak.patch
queue-3.8/cgroup-fix-broken-file-xattrs.patch
queue-3.8/sysfs-fix-use-after-free-in-case-of-concurrent-read-write-and-readdir.patch
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