---

yaml --- r: 305989 b: refs/heads/master c: 1a48e2a h: refs/heads/master i: 305987: 83aa864 v: v3
git-mirror · Apr 8, 2012 · 50eb4e0 · 50eb4e0
1 parent 12bea7a
commit 50eb4e0
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Showing 6 changed files with 29 additions and 24 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 973c5914260d75292f71a4729753086b9e863d57
+refs/heads/master: 1a48e2ac034d47ed843081c4523b63c46b46888b
diff --git a/trunk/fs/inode.c b/trunk/fs/inode.c
@@ -1732,11 +1732,9 @@ EXPORT_SYMBOL(inode_init_owner);
  */
 bool inode_owner_or_capable(const struct inode *inode)
 {
-	struct user_namespace *ns = inode_userns(inode);
-
-	if (current_user_ns() == ns && current_fsuid() == inode->i_uid)
+	if (current_fsuid() == inode->i_uid)
 		return true;
-	if (ns_capable(ns, CAP_FOWNER))
+	if (inode_capable(inode, CAP_FOWNER))
 		return true;
 	return false;
 }

diff --git a/trunk/fs/namei.c b/trunk/fs/namei.c
@@ -228,9 +228,6 @@ static int acl_permission_check(struct inode *inode, int mask)
 {
 	unsigned int mode = inode->i_mode;
 
-	if (current_user_ns() != inode_userns(inode))
-		goto other_perms;
-
 	if (likely(current_fsuid() == inode->i_uid))
 		mode >>= 6;
 	else {
@@ -244,7 +241,6 @@ static int acl_permission_check(struct inode *inode, int mask)
 			mode >>= 3;
 	}
 
-other_perms:
 	/*
 	 * If the DACs are ok we don't need any capability check.
 	 */
@@ -280,10 +276,10 @@ int generic_permission(struct inode *inode, int mask)
 
 	if (S_ISDIR(inode->i_mode)) {
 		/* DACs are overridable for directories */
-		if (ns_capable(inode_userns(inode), CAP_DAC_OVERRIDE))
+		if (inode_capable(inode, CAP_DAC_OVERRIDE))
 			return 0;
 		if (!(mask & MAY_WRITE))
-			if (ns_capable(inode_userns(inode), CAP_DAC_READ_SEARCH))
+			if (inode_capable(inode, CAP_DAC_READ_SEARCH))
 				return 0;
 		return -EACCES;
 	}
@@ -293,15 +289,15 @@ int generic_permission(struct inode *inode, int mask)
 	 * at least one exec bit set.
 	 */
 	if (!(mask & MAY_EXEC) || (inode->i_mode & S_IXUGO))
-		if (ns_capable(inode_userns(inode), CAP_DAC_OVERRIDE))
+		if (inode_capable(inode, CAP_DAC_OVERRIDE))
 			return 0;
 
 	/*
 	 * Searching includes executable on directories, else just read.
 	 */
 	mask &= MAY_READ | MAY_WRITE | MAY_EXEC;
 	if (mask == MAY_READ)
-		if (ns_capable(inode_userns(inode), CAP_DAC_READ_SEARCH))
+		if (inode_capable(inode, CAP_DAC_READ_SEARCH))
 			return 0;
 
 	return -EACCES;
@@ -1964,15 +1960,11 @@ static inline int check_sticky(struct inode *dir, struct inode *inode)
 
 	if (!(dir->i_mode & S_ISVTX))
 		return 0;
-	if (current_user_ns() != inode_userns(inode))
-		goto other_userns;
 	if (inode->i_uid == fsuid)
 		return 0;
 	if (dir->i_uid == fsuid)
 		return 0;
-
-other_userns:
-	return !ns_capable(inode_userns(inode), CAP_FOWNER);
+	return !inode_capable(inode, CAP_FOWNER);
 }
 
 /*

diff --git a/trunk/include/linux/capability.h b/trunk/include/linux/capability.h
@@ -374,6 +374,7 @@ struct cpu_vfs_cap_data {
 
 #ifdef __KERNEL__
 
+struct inode;
 struct dentry;
 struct user_namespace;
 
@@ -548,6 +549,7 @@ extern bool has_ns_capability_noaudit(struct task_struct *t,
 extern bool capable(int cap);
 extern bool ns_capable(struct user_namespace *ns, int cap);
 extern bool nsown_capable(int cap);
+extern bool inode_capable(const struct inode *inode, int cap);
 
 /* audit system wants to get cap info from files as well */
 extern int get_vfs_caps_from_disk(const struct dentry *dentry, struct cpu_vfs_cap_data *cpu_caps);

diff --git a/trunk/include/linux/fs.h b/trunk/include/linux/fs.h
@@ -1522,12 +1522,6 @@ enum {
 #define vfs_check_frozen(sb, level) \
 	wait_event((sb)->s_wait_unfrozen, ((sb)->s_frozen < (level)))
 
-/*
- * until VFS tracks user namespaces for inodes, just make all files
- * belong to init_user_ns
- */
-extern struct user_namespace init_user_ns;
-#define inode_userns(inode) (&init_user_ns)
 extern bool inode_owner_or_capable(const struct inode *inode);
 
 /* not quite ready to be deprecated, but... */

diff --git a/trunk/kernel/capability.c b/trunk/kernel/capability.c
@@ -419,3 +419,22 @@ bool nsown_capable(int cap)
 {
 	return ns_capable(current_user_ns(), cap);
 }
+
+/**
+ * inode_capable - Check superior capability over inode
+ * @inode: The inode in question
+ * @cap: The capability in question
+ *
+ * Return true if the current task has the given superior capability
+ * targeted at it's own user namespace and that the given inode is owned
+ * by the current user namespace or a child namespace.
+ *
+ * Currently inodes can only be owned by the initial user namespace.
+ *
+ */
+bool inode_capable(const struct inode *inode, int cap)
+{
+	struct user_namespace *ns = current_user_ns();
+
+	return ns_capable(ns, cap) && (ns == &init_user_ns);
+}