proc base rcu fix

Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com>

diff --git a/fs/proc/base.c b/fs/proc/base.c
index e55ecd42642bccc23c53356bdb0d94d73f853bde..65e2358548fbfcca62b9957099cfb509162bb1d5 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -2339,6 +2339,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
                mmput(mm);
                goto out_put_task;
        }
+       rcu_read_lock();
 
        nr_files = 0;
        mas.tree = &mm->mm_mt;
@@ -2372,6 +2373,7 @@ proc_map_files_readdir(struct file *file, struct dir_context *ctx)
                p->end = vma->vm_end;
                p->mode = vma->vm_file->f_mode;
        }
+       rcu_read_unlock();
        mmap_read_unlock(mm);
        mmput(mm);