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 22:03:38 +0000 (06:03 +0800)
commitb19c8d0b4c18448006ce960d1c2a3902c481f9b9
tree3ac1528bde833d6b4ed9b8412a61415df8b8d547
parent225234a28f6f7655ae3ed5bfbba536d0468209bd
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