1 files changed, 85 insertions, 8 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 57b8159f26f3..d2d3108a611c 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -81,6 +81,7 @@
 #include <linux/oom.h>
 #include <linux/elf.h>
 #include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
 #include <linux/fs_struct.h>
 #include <linux/slab.h>
 #include <linux/flex_array.h>
@@ -1561,8 +1562,8 @@ int pid_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
 	generic_fillattr(inode, stat);
 
 	rcu_read_lock();
-	stat->uid = 0;
-	stat->gid = 0;
+	stat->uid = GLOBAL_ROOT_UID;
+	stat->gid = GLOBAL_ROOT_GID;
 	task = pid_task(proc_pid(inode), PIDTYPE_PID);
 	if (task) {
 		if (!has_pid_permissions(pid, task, 2)) {
@@ -1622,8 +1623,8 @@ int pid_revalidate(struct dentry *dentry, struct nameidata *nd)
 			inode->i_gid = cred->egid;
 			rcu_read_unlock();
 		} else {
-			inode->i_uid = 0;
-			inode->i_gid = 0;
+			inode->i_uid = GLOBAL_ROOT_UID;
+			inode->i_gid = GLOBAL_ROOT_GID;
 		}
 		inode->i_mode &= ~(S_ISUID | S_ISGID);
 		security_task_to_inode(task, inode);
@@ -1815,8 +1816,8 @@ static int tid_fd_revalidate(struct dentry *dentry, struct nameidata *nd)
 					inode->i_gid = cred->egid;
 					rcu_read_unlock();
 				} else {
-					inode->i_uid = 0;
-					inode->i_gid = 0;
+					inode->i_uid = GLOBAL_ROOT_UID;
+					inode->i_gid = GLOBAL_ROOT_GID;
 				}
 
 				i_mode = S_IFLNK;
@@ -2045,8 +2046,8 @@ static int map_files_d_revalidate(struct dentry *dentry, struct nameidata *nd)
 			inode->i_gid = cred->egid;
 			rcu_read_unlock();
 		} else {
-			inode->i_uid = 0;
-			inode->i_gid = 0;
+			inode->i_uid = GLOBAL_ROOT_UID;
+			inode->i_gid = GLOBAL_ROOT_GID;
 		}
 		security_task_to_inode(task, inode);
 		status = 1;
@@ -2924,6 +2925,74 @@ static int proc_tgid_io_accounting(struct task_struct *task, char *buffer)
 }
 #endif /* CONFIG_TASK_IO_ACCOUNTING */
 
+#ifdef CONFIG_USER_NS
+static int proc_id_map_open(struct inode *inode, struct file *file,
+	struct seq_operations *seq_ops)
+{
+	struct user_namespace *ns = NULL;
+	struct task_struct *task;
+	struct seq_file *seq;
+	int ret = -EINVAL;
+
+	task = get_proc_task(inode);
+	if (task) {
+		rcu_read_lock();
+		ns = get_user_ns(task_cred_xxx(task, user_ns));
+		rcu_read_unlock();
+		put_task_struct(task);
+	}
+	if (!ns)
+		goto err;
+
+	ret = seq_open(file, seq_ops);
+	if (ret)
+		goto err_put_ns;
+
+	seq = file->private_data;
+	seq->private = ns;
+
+	return 0;
+err_put_ns:
+	put_user_ns(ns);
+err:
+	return ret;
+}
+
+static int proc_id_map_release(struct inode *inode, struct file *file)
+{
+	struct seq_file *seq = file->private_data;
+	struct user_namespace *ns = seq->private;
+	put_user_ns(ns);
+	return seq_release(inode, file);
+}
+
+static int proc_uid_map_open(struct inode *inode, struct file *file)
+{
+	return proc_id_map_open(inode, file, &proc_uid_seq_operations);
+}
+
+static int proc_gid_map_open(struct inode *inode, struct file *file)
+{
+	return proc_id_map_open(inode, file, &proc_gid_seq_operations);
+}
+
+static const struct file_operations proc_uid_map_operations = {
+	.open		= proc_uid_map_open,
+	.write		= proc_uid_map_write,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= proc_id_map_release,
+};
+
+static const struct file_operations proc_gid_map_operations = {
+	.open		= proc_gid_map_open,
+	.write		= proc_gid_map_write,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= proc_id_map_release,
+};
+#endif /* CONFIG_USER_NS */
+
 static int proc_pid_personality(struct seq_file *m, struct pid_namespace *ns,
 				struct pid *pid, struct task_struct *task)
 {
@@ -3026,6 +3095,10 @@ static const struct pid_entry tgid_base_stuff[] = {
 #ifdef CONFIG_HARDWALL
 	INF("hardwall",   S_IRUGO, proc_pid_hardwall),
 #endif
+#ifdef CONFIG_USER_NS
+	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
+	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
+#endif
 };
 
 static int proc_tgid_base_readdir(struct file * filp,
@@ -3381,6 +3454,10 @@ static const struct pid_entry tid_base_stuff[] = {
 #ifdef CONFIG_HARDWALL
 	INF("hardwall",   S_IRUGO, proc_pid_hardwall),
 #endif
+#ifdef CONFIG_USER_NS
+	REG("uid_map",    S_IRUGO|S_IWUSR, proc_uid_map_operations),
+	REG("gid_map",    S_IRUGO|S_IWUSR, proc_gid_map_operations),
+#endif
 };
 
 static int proc_tid_base_readdir(struct file * filp,