| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.4 17/35] cpuset: fix a race condition in __cpuset_node_allowed_softwall() | Date | Thu, 20 Mar 2014 17:11:08 -0700 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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From: Li Zefan <lizefan@huawei.com>
commit 99afb0fd5f05aac467ffa85c36778fec4396209b upstream.
It's not safe to access task's cpuset after releasing task_lock(). Holding callback_mutex won't help.
Signed-off-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/cpuset.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -2338,9 +2338,9 @@ int __cpuset_node_allowed_softwall(int n task_lock(current); cs = nearest_hardwall_ancestor(task_cs(current)); + allowed = node_isset(node, cs->mems_allowed); task_unlock(current); - allowed = node_isset(node, cs->mems_allowed); mutex_unlock(&callback_mutex); return allowed; }
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