---

yaml --- r: 252733 b: refs/heads/master c: 69b4573 h: refs/heads/master i: 252731: f25320b v: v3
git-mirror · May 28, 2011 · dcde8d4 · dcde8d4
1 parent e538340
commit dcde8d4
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Showing 5 changed files with 38 additions and 5 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: d76ee18a8551e33ad7dbd55cac38bc7b094f3abb
+refs/heads/master: 69b4573296469fd3f70cf7044693074980517067
diff --git a/trunk/fs/attr.c b/trunk/fs/attr.c
@@ -175,6 +175,13 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
 			return -EPERM;
 	}
 
+	if ((ia_valid & ATTR_MODE)) {
+		mode_t amode = attr->ia_mode;
+		/* Flag setting protected by i_mutex */
+		if (is_sxid(amode))
+			inode->i_flags &= ~S_NOSEC;
+	}
+
 	now = current_fs_time(inode->i_sb);
 
 	attr->ia_ctime = now;

diff --git a/trunk/fs/xattr.c b/trunk/fs/xattr.c
@@ -91,16 +91,19 @@ int __vfs_setxattr_noperm(struct dentry *dentry, const char *name,
 {
 	struct inode *inode = dentry->d_inode;
 	int error = -EOPNOTSUPP;
+	int issec = !strncmp(name, XATTR_SECURITY_PREFIX,
+				   XATTR_SECURITY_PREFIX_LEN);
 
+	if (issec)
+		inode->i_flags &= ~S_NOSEC;
 	if (inode->i_op->setxattr) {
 		error = inode->i_op->setxattr(dentry, name, value, size, flags);
 		if (!error) {
 			fsnotify_xattr(dentry);
 			security_inode_post_setxattr(dentry, name, value,
 						     size, flags);
 		}
-	} else if (!strncmp(name, XATTR_SECURITY_PREFIX,
-				XATTR_SECURITY_PREFIX_LEN)) {
+	} else if (issec) {
 		const char *suffix = name + XATTR_SECURITY_PREFIX_LEN;
 		error = security_inode_setsecurity(inode, suffix, value,
 						   size, flags);

diff --git a/trunk/include/linux/fs.h b/trunk/include/linux/fs.h
@@ -237,6 +237,7 @@ struct inodes_stat_t {
 #define S_PRIVATE	512	/* Inode is fs-internal */
 #define S_IMA		1024	/* Inode has an associated IMA struct */
 #define S_AUTOMOUNT	2048	/* Automount/referral quasi-directory */
+#define S_NOSEC		4096	/* no suid or xattr security attributes */
 
 /*
  * Note that nosuid etc flags are inode-specific: setting some file-system
@@ -273,6 +274,7 @@ struct inodes_stat_t {
 #define IS_PRIVATE(inode)	((inode)->i_flags & S_PRIVATE)
 #define IS_IMA(inode)		((inode)->i_flags & S_IMA)
 #define IS_AUTOMOUNT(inode)	((inode)->i_flags & S_AUTOMOUNT)
+#define IS_NOSEC(inode)		((inode)->i_flags & S_NOSEC)
 
 /* the read-only stuff doesn't really belong here, but any other place is
    probably as bad and I don't want to create yet another include file. */
@@ -2582,5 +2584,16 @@ int __init get_filesystem_list(char *buf);
 #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \
 					    (flag & __FMODE_NONOTIFY)))
 
+static inline int is_sxid(mode_t mode)
+{
+	return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP));
+}
+
+static inline void inode_has_no_xattr(struct inode *inode)
+{
+	if (!is_sxid(inode->i_mode))
+		inode->i_flags |= S_NOSEC;
+}
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_FS_H */
diff --git a/trunk/mm/filemap.c b/trunk/mm/filemap.c
@@ -1982,16 +1982,26 @@ static int __remove_suid(struct dentry *dentry, int kill)
 int file_remove_suid(struct file *file)
 {
 	struct dentry *dentry = file->f_path.dentry;
-	int killsuid = should_remove_suid(dentry);
-	int killpriv = security_inode_need_killpriv(dentry);
+	struct inode *inode = dentry->d_inode;
+	int killsuid;
+	int killpriv;
 	int error = 0;
 
+	/* Fast path for nothing security related */
+	if (IS_NOSEC(inode))
+		return 0;
+
+	killsuid = should_remove_suid(dentry);
+	killpriv = security_inode_need_killpriv(dentry);
+
 	if (killpriv < 0)
 		return killpriv;
 	if (killpriv)
 		error = security_inode_killpriv(dentry);
 	if (!error && killsuid)
 		error = __remove_suid(dentry, killsuid);
+	if (!error)
+		inode->i_flags |= S_NOSEC;
 
 	return error;
 }