cpuset: fix cpuset_print_task_mems_allowed() vs rename() race
authorLi Zefan <lizefan@huawei.com>
Fri, 25 Jan 2013 08:08:01 +0000 (16:08 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 3 Mar 2013 22:06:44 +0000 (06:06 +0800)
commita74e9a386f6e775f88061f7958b8b34c6742f926
treea71c10ec1690efe570ec1236198f499faa9c661b
parent68412b1718c488e58783d1c576d0aeb34012092d
cpuset: fix cpuset_print_task_mems_allowed() vs rename() race

commit 63f43f55c9bbc14f76b582644019b8a07dc8219a upstream.

rename() will change dentry->d_name. The result of this race can
be worse than seeing partially rewritten name, but we might access
a stale pointer because rename() will re-allocate memory to hold
a longer name.

It's safe in the protection of dentry->d_lock.

v2: check NULL dentry before acquiring dentry lock.

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