proc: Better ownership of files for non-dumpable tasks in user namespaces
Instead of making the files owned by the GLOBAL_ROOT_USER. Make
non-dumpable files whose mm has always lived in a user namespace owned
by the user namespace root. This allows the container root to have
things work as expected in a container.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index 4274f83..00ce153 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -84,7 +84,6 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
{
struct files_struct *files;
struct task_struct *task;
- const struct cred *cred;
struct inode *inode;
unsigned int fd;
@@ -108,16 +107,7 @@ static int tid_fd_revalidate(struct dentry *dentry, unsigned int flags)
rcu_read_unlock();
put_files_struct(files);
- if (task_dumpable(task)) {
- rcu_read_lock();
- cred = __task_cred(task);
- inode->i_uid = cred->euid;
- inode->i_gid = cred->egid;
- rcu_read_unlock();
- } else {
- inode->i_uid = GLOBAL_ROOT_UID;
- inode->i_gid = GLOBAL_ROOT_GID;
- }
+ task_dump_owner(task, 0, &inode->i_uid, &inode->i_gid);
if (S_ISLNK(inode->i_mode)) {
unsigned i_mode = S_IFLNK;
