diff options
| -rw-r--r-- | fs/proc/base.c | 29 |
1 files changed, 16 insertions, 13 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index c7f85544157..f0db7f616ac 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1074,24 +1074,27 @@ static int proc_check_dentry_visible(struct inode *inode, * namespace, or are simply process local (like pipes). */ struct task_struct *task; - struct files_struct *task_files, *files; int error = -EACCES; /* See if the the two tasks share a commone set of * file descriptors. If so everything is visible. */ - task = get_proc_task(inode); - if (!task) - goto out; - files = get_files_struct(current); - task_files = get_files_struct(task); - if (files && task_files && (files == task_files)) - error = 0; - if (task_files) - put_files_struct(task_files); - if (files) - put_files_struct(files); - put_task_struct(task); + rcu_read_lock(); + task = tref_task(proc_tref(inode)); + if (task) { + struct files_struct *task_files, *files; + /* This test answeres the question: + * Is there a point in time since we looked up the + * file descriptor where the two tasks share the + * same files struct? + */ + rmb(); + files = current->files; + task_files = task->files; + if (files && (files == task_files)) + error = 0; + } + rcu_read_unlock(); if (!error) goto out; |