jfs: don't allow os2 xattr namespace overlap with others (aca0fa34) · Commits · 戴 / test

fs/jfs/xattr.c

+38 −49

Original line number	Diff line number	Diff line
		@@ -86,46 +86,25 @@ struct ea_buffer {
		#define EA_MALLOC 0x0008


		static int is_known_namespace(const char *name)
		{
		if (strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) &&
		strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
		strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
		strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
		return false;

		return true;
		}

		/*
		* These three routines are used to recognize on-disk extended attributes
		* that are in a recognized namespace. If the attribute is not recognized,
		* "os2." is prepended to the name
		*/
		static inline int is_os2_xattr(struct jfs_ea *ea)
		static int is_os2_xattr(struct jfs_ea *ea)
		{
		/*
		* Check for "system."
		*/
		if ((ea->namelen >= XATTR_SYSTEM_PREFIX_LEN) &&
		!strncmp(ea->name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
		return false;
		/*
		* Check for "user."
		*/
		if ((ea->namelen >= XATTR_USER_PREFIX_LEN) &&
		!strncmp(ea->name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
		return false;
		/*
		* Check for "security."
		*/
		if ((ea->namelen >= XATTR_SECURITY_PREFIX_LEN) &&
		!strncmp(ea->name, XATTR_SECURITY_PREFIX,
		XATTR_SECURITY_PREFIX_LEN))
		return false;
		/*
		* Check for "trusted."
		*/
		if ((ea->namelen >= XATTR_TRUSTED_PREFIX_LEN) &&
		!strncmp(ea->name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
		return false;
		/*
		* Add any other valid namespace prefixes here
		*/

		/*
		* We assume it's OS/2's flat namespace
		*/
		return true;
		return !is_known_namespace(ea->name);
		}

		static inline int name_size(struct jfs_ea *ea)
		@@ -764,13 +743,23 @@ static int can_set_xattr(struct inode inode, const char name,
		if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
		return can_set_system_xattr(inode, name, value, value_len);

		if (!strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN)) {
		/*
		* This makes sure that we aren't trying to set an
		* attribute in a different namespace by prefixing it
		* with "os2."
		*/
		if (is_known_namespace(name + XATTR_OS2_PREFIX_LEN))
		return -EOPNOTSUPP;
		return 0;
		}

		/*
		* Don't allow setting an attribute in an unknown namespace.
		*/
		if (strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) &&
		strncmp(name, XATTR_SECURITY_PREFIX, XATTR_SECURITY_PREFIX_LEN) &&
		strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN) &&
		strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN))
		strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
		return -EOPNOTSUPP;

		return 0;
		@@ -952,19 +941,8 @@ ssize_t __jfs_getxattr(struct inode inode, const char name, void *data,
		int xattr_size;
		ssize_t size;
		int namelen = strlen(name);
		char *os2name = NULL;
		char *value;

		if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
		os2name = kmalloc(namelen - XATTR_OS2_PREFIX_LEN + 1,
		GFP_KERNEL);
		if (!os2name)
		return -ENOMEM;
		strcpy(os2name, name + XATTR_OS2_PREFIX_LEN);
		name = os2name;
		namelen -= XATTR_OS2_PREFIX_LEN;
		}

		down_read(&JFS_IP(inode)->xattr_sem);

		xattr_size = ea_get(inode, &ea_buf, 0);
		@@ -1002,8 +980,6 @@ ssize_t __jfs_getxattr(struct inode inode, const char name, void *data,
		out:
		up_read(&JFS_IP(inode)->xattr_sem);

		kfree(os2name);

		return size;
		}

		@@ -1012,6 +988,19 @@ ssize_t jfs_getxattr(struct dentry dentry, const char name, void *data,
		{
		int err;

		if (strncmp(name, XATTR_OS2_PREFIX, XATTR_OS2_PREFIX_LEN) == 0) {
		/*
		* skip past "os2." prefix
		*/
		name += XATTR_OS2_PREFIX_LEN;
		/*
		* Don't allow retrieving properly prefixed attributes
		* by prepending them with "os2."
		*/
		if (is_known_namespace(name))
		return -EOPNOTSUPP;
		}

		err = __jfs_getxattr(dentry->d_inode, name, data, buf_size);

		return err;

Admin message