On Fri, Jan 25, 2013 at 03:09:48PM +0800, Li Zefan wrote: > 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. > > Signed-off-by: Li Zefan <lizefan@xxxxxxxxxx> > --- > kernel/cpuset.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/kernel/cpuset.c b/kernel/cpuset.c > index 16be7c9..b2476c2 100644 > --- a/kernel/cpuset.c > +++ b/kernel/cpuset.c > @@ -2606,8 +2606,12 @@ void cpuset_print_task_mems_allowed(struct task_struct *tsk) > > dentry = task_cs(tsk)->css.cgroup->dentry; > spin_lock(&cpuset_buffer_lock); > + > + spin_lock(&dentry->d_lock); > snprintf(cpuset_name, CPUSET_NAME_LEN, > dentry ? (const char *)dentry->d_name.name : "/"); Ahem... Can dentry actually be NULL here? If not, this conditional is bogus; otherwise, spin_lock(&dentry->d_lock) is going to blow up... -- To unsubscribe from this list: send the line "unsubscribe cgroups" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
