vfs: Distinguish between full xattr names and proper prefixes

Add an additional "name" field to struct xattr_handler. When the name is set, the handler matches attributes with exactly that name. When the prefix is set instead, the handler matches attributes with the given prefix and with a non-empty suffix. This patch should avoid bugs like the one fixed in commit c361016 in the future. Signed-off-by: Andreas Gruenbacher <[email protected]> Reviewed-by: James Morris <[email protected]> Signed-off-by: Al Viro <[email protected]>
torvalds · Dec 7, 2015 · 98e9cb5 · 98e9cb5
1 parent 97d7929
commit 98e9cb5
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Showing 22 changed files with 47 additions and 130 deletions.
diff --git a/fs/9p/acl.c b/fs/9p/acl.c
@@ -220,15 +220,12 @@ static int v9fs_xattr_get_acl(const struct xattr_handler *handler,
 	struct posix_acl *acl;
 	int error;
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-
 	v9ses = v9fs_dentry2v9ses(dentry);
 	/*
 	 * We allow set/get/list of acl when access=client is not specified
 	 */
 	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
-		return v9fs_xattr_get(dentry, handler->prefix, buffer, size);
+		return v9fs_xattr_get(dentry, handler->name, buffer, size);
 
 	acl = v9fs_get_cached_acl(d_inode(dentry), handler->flags);
 	if (IS_ERR(acl))
@@ -250,16 +247,13 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
 	struct v9fs_session_info *v9ses;
 	struct inode *inode = d_inode(dentry);
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-
 	v9ses = v9fs_dentry2v9ses(dentry);
 	/*
 	 * set the attribute on the remote. Without even looking at the
 	 * xattr value. We leave it to the server to validate
 	 */
 	if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT)
-		return v9fs_xattr_set(dentry, handler->prefix, value, size,
+		return v9fs_xattr_set(dentry, handler->name, value, size,
 				      flags);
 
 	if (S_ISLNK(inode->i_mode))
@@ -319,7 +313,7 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
 	default:
 		BUG();
 	}
-	retval = v9fs_xattr_set(dentry, handler->prefix, value, size, flags);
+	retval = v9fs_xattr_set(dentry, handler->name, value, size, flags);
 	if (!retval)
 		set_cached_acl(inode, handler->flags, acl);
 err_out:
@@ -328,14 +322,14 @@ static int v9fs_xattr_set_acl(const struct xattr_handler *handler,
 }
 
 const struct xattr_handler v9fs_xattr_acl_access_handler = {
-	.prefix	= XATTR_NAME_POSIX_ACL_ACCESS,
+	.name	= XATTR_NAME_POSIX_ACL_ACCESS,
 	.flags	= ACL_TYPE_ACCESS,
 	.get	= v9fs_xattr_get_acl,
 	.set	= v9fs_xattr_set_acl,
 };
 
 const struct xattr_handler v9fs_xattr_acl_default_handler = {
-	.prefix	= XATTR_NAME_POSIX_ACL_DEFAULT,
+	.name	= XATTR_NAME_POSIX_ACL_DEFAULT,
 	.flags	= ACL_TYPE_DEFAULT,
 	.get	= v9fs_xattr_get_acl,
 	.set	= v9fs_xattr_set_acl,

diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c
@@ -143,8 +143,6 @@ static int v9fs_xattr_handler_get(const struct xattr_handler *handler,
 {
 	const char *full_name = xattr_full_name(handler, name);
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return v9fs_xattr_get(dentry, full_name, buffer, size);
 }
 
@@ -154,8 +152,6 @@ static int v9fs_xattr_handler_set(const struct xattr_handler *handler,
 {
 	const char *full_name = xattr_full_name(handler, name);
 
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return v9fs_xattr_set(dentry, full_name, value, size, flags);
 }
 

diff --git a/fs/ext2/xattr_security.c b/fs/ext2/xattr_security.c
@@ -28,8 +28,6 @@ ext2_xattr_security_get(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
 			      buffer, size);
 }
@@ -39,8 +37,6 @@ ext2_xattr_security_set(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_SECURITY, name,
 			      value, size, flags);
 }

diff --git a/fs/ext2/xattr_trusted.c b/fs/ext2/xattr_trusted.c
@@ -32,8 +32,6 @@ ext2_xattr_trusted_get(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name,
 		       void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
 			      buffer, size);
 }
@@ -43,8 +41,6 @@ ext2_xattr_trusted_set(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name,
 		       const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext2_xattr_set(d_inode(dentry), EXT2_XATTR_INDEX_TRUSTED, name,
 			      value, size, flags);
 }

diff --git a/fs/ext2/xattr_user.c b/fs/ext2/xattr_user.c
@@ -34,8 +34,6 @@ ext2_xattr_user_get(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 	return ext2_xattr_get(d_inode(dentry), EXT2_XATTR_INDEX_USER,
@@ -47,8 +45,6 @@ ext2_xattr_user_set(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 

diff --git a/fs/ext4/xattr_security.c b/fs/ext4/xattr_security.c
@@ -33,8 +33,6 @@ ext4_xattr_security_get(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY,
 			      name, buffer, size);
 }
@@ -44,8 +42,6 @@ ext4_xattr_security_set(const struct xattr_handler *handler,
 			struct dentry *dentry, const char *name,
 			const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_SECURITY,
 			      name, value, size, flags);
 }

diff --git a/fs/ext4/xattr_trusted.c b/fs/ext4/xattr_trusted.c
@@ -36,8 +36,6 @@ ext4_xattr_trusted_get(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name, void *buffer,
 		       size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED,
 			      name, buffer, size);
 }
@@ -47,8 +45,6 @@ ext4_xattr_trusted_set(const struct xattr_handler *handler,
 		       struct dentry *dentry, const char *name,
 		       const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_TRUSTED,
 			      name, value, size, flags);
 }

diff --git a/fs/ext4/xattr_user.c b/fs/ext4/xattr_user.c
@@ -35,8 +35,6 @@ ext4_xattr_user_get(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    void *buffer, size_t size)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 	return ext4_xattr_get(d_inode(dentry), EXT4_XATTR_INDEX_USER,
@@ -48,8 +46,6 @@ ext4_xattr_user_set(const struct xattr_handler *handler,
 		    struct dentry *dentry, const char *name,
 		    const void *value, size_t size, int flags)
 {
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	if (!test_opt(dentry->d_sb, XATTR_USER))
 		return -EOPNOTSUPP;
 	return ext4_xattr_set(d_inode(dentry), EXT4_XATTR_INDEX_USER,

diff --git a/fs/f2fs/xattr.c b/fs/f2fs/xattr.c
@@ -30,6 +30,7 @@ static size_t f2fs_xattr_generic_list(const struct xattr_handler *handler,
 		const char *name, size_t len)
 {
 	struct f2fs_sb_info *sbi = F2FS_SB(dentry->d_sb);
+	const char *prefix;
 	int total_len, prefix_len;
 
 	switch (handler->flags) {
@@ -47,10 +48,11 @@ static size_t f2fs_xattr_generic_list(const struct xattr_handler *handler,
 		return -EINVAL;
 	}
 
-	prefix_len = strlen(handler->prefix);
+	prefix = xattr_prefix(handler);
+	prefix_len = strlen(prefix);
 	total_len = prefix_len + len + 1;
 	if (list && total_len <= list_size) {
-		memcpy(list, handler->prefix, prefix_len);
+		memcpy(list, prefix, prefix_len);
 		memcpy(list + prefix_len, name, len);
 		list[prefix_len + len] = '\0';
 	}
@@ -77,8 +79,6 @@ static int f2fs_xattr_generic_get(const struct xattr_handler *handler,
 	default:
 		return -EINVAL;
 	}
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
 	return f2fs_getxattr(d_inode(dentry), handler->flags, name,
 			     buffer, size, NULL);
 }
@@ -103,9 +103,6 @@ static int f2fs_xattr_generic_set(const struct xattr_handler *handler,
 	default:
 		return -EINVAL;
 	}
-	if (strcmp(name, "") == 0)
-		return -EINVAL;
-
 	return f2fs_setxattr(d_inode(dentry), handler->flags, name,
 					value, size, NULL, flags);
 }
@@ -114,7 +111,7 @@ static size_t f2fs_xattr_advise_list(const struct xattr_handler *handler,
 		struct dentry *dentry, char *list, size_t list_size,
 		const char *name, size_t len)
 {
-	const char *xname = F2FS_SYSTEM_ADVISE_PREFIX;
+	const char *xname = F2FS_SYSTEM_ADVISE_NAME;
 	size_t size;
 
 	size = strlen(xname) + 1;
@@ -129,9 +126,6 @@ static int f2fs_xattr_advise_get(const struct xattr_handler *handler,
 {
 	struct inode *inode = d_inode(dentry);
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
-
 	if (buffer)
 		*((char *)buffer) = F2FS_I(inode)->i_advise;
 	return sizeof(char);
@@ -143,8 +137,6 @@ static int f2fs_xattr_advise_set(const struct xattr_handler *handler,
 {
 	struct inode *inode = d_inode(dentry);
 
-	if (strcmp(name, "") != 0)
-		return -EINVAL;
 	if (!inode_owner_or_capable(inode))
 		return -EPERM;
 	if (value == NULL)
@@ -197,7 +189,7 @@ const struct xattr_handler f2fs_xattr_trusted_handler = {
 };
 
 const struct xattr_handler f2fs_xattr_advise_handler = {
-	.prefix = F2FS_SYSTEM_ADVISE_PREFIX,
+	.name	= F2FS_SYSTEM_ADVISE_NAME,
 	.flags	= F2FS_XATTR_INDEX_ADVISE,
 	.list   = f2fs_xattr_advise_list,
 	.get    = f2fs_xattr_advise_get,

diff --git a/fs/f2fs/xattr.h b/fs/f2fs/xattr.h
@@ -27,7 +27,7 @@
 #define F2FS_XATTR_REFCOUNT_MAX         1024
 
 /* Name indexes */
-#define F2FS_SYSTEM_ADVISE_PREFIX		"system.advise"
+#define F2FS_SYSTEM_ADVISE_NAME			"system.advise"
 #define F2FS_XATTR_INDEX_USER			1
 #define F2FS_XATTR_INDEX_POSIX_ACL_ACCESS	2
 #define F2FS_XATTR_INDEX_POSIX_ACL_DEFAULT	3

diff --git a/fs/hfsplus/xattr.c b/fs/hfsplus/xattr.c
@@ -431,9 +431,6 @@ int hfsplus_setxattr(struct dentry *dentry, const char *name,
 	char *xattr_name;
 	int res;
 
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 		GFP_KERNEL);
 	if (!xattr_name)
@@ -589,9 +586,6 @@ ssize_t hfsplus_getxattr(struct dentry *dentry, const char *name,
 	int res;
 	char *xattr_name;
 
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	xattr_name = kmalloc(NLS_MAX_CHARSET_SIZE * HFSPLUS_ATTR_MAX_STRLEN + 1,
 			     GFP_KERNEL);
 	if (!xattr_name)
@@ -853,9 +847,6 @@ static int hfsplus_osx_getxattr(const struct xattr_handler *handler,
 				struct dentry *dentry, const char *name,
 				void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	/*
 	 * Don't allow retrieving properly prefixed attributes
 	 * by prepending them with "osx."
@@ -876,9 +867,6 @@ static int hfsplus_osx_setxattr(const struct xattr_handler *handler,
 				struct dentry *dentry, const char *name,
 				const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	/*
 	 * Don't allow setting properly prefixed attributes
 	 * by prepending them with "osx."

diff --git a/fs/jffs2/security.c b/fs/jffs2/security.c
@@ -52,9 +52,6 @@ static int jffs2_security_getxattr(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *name,
 				   void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	return do_jffs2_getxattr(d_inode(dentry), JFFS2_XPREFIX_SECURITY,
 				 name, buffer, size);
 }
@@ -63,9 +60,6 @@ static int jffs2_security_setxattr(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *name,
 				   const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
-
 	return do_jffs2_setxattr(d_inode(dentry), JFFS2_XPREFIX_SECURITY,
 				 name, buffer, size, flags);
 }

diff --git a/fs/jffs2/xattr_trusted.c b/fs/jffs2/xattr_trusted.c
@@ -20,8 +20,6 @@ static int jffs2_trusted_getxattr(const struct xattr_handler *handler,
 				  struct dentry *dentry, const char *name,
 				  void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_getxattr(d_inode(dentry), JFFS2_XPREFIX_TRUSTED,
 				 name, buffer, size);
 }
@@ -30,8 +28,6 @@ static int jffs2_trusted_setxattr(const struct xattr_handler *handler,
 				  struct dentry *dentry, const char *name,
 				  const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_setxattr(d_inode(dentry), JFFS2_XPREFIX_TRUSTED,
 				 name, buffer, size, flags);
 }

diff --git a/fs/jffs2/xattr_user.c b/fs/jffs2/xattr_user.c
@@ -20,8 +20,6 @@ static int jffs2_user_getxattr(const struct xattr_handler *handler,
 			       struct dentry *dentry, const char *name,
 			       void *buffer, size_t size)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_getxattr(d_inode(dentry), JFFS2_XPREFIX_USER,
 				 name, buffer, size);
 }
@@ -30,8 +28,6 @@ static int jffs2_user_setxattr(const struct xattr_handler *handler,
 			       struct dentry *dentry, const char *name,
 			       const void *buffer, size_t size, int flags)
 {
-	if (!strcmp(name, ""))
-		return -EINVAL;
 	return do_jffs2_setxattr(d_inode(dentry), JFFS2_XPREFIX_USER,
 				 name, buffer, size, flags);
 }

diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
@@ -6253,19 +6253,13 @@ static int nfs4_xattr_set_nfs4_acl(const struct xattr_handler *handler,
 				   const void *buf, size_t buflen,
 				   int flags)
 {
-	if (strcmp(key, "") != 0)
-		return -EINVAL;
-
 	return nfs4_proc_set_acl(d_inode(dentry), buf, buflen);
 }
 
 static int nfs4_xattr_get_nfs4_acl(const struct xattr_handler *handler,
 				   struct dentry *dentry, const char *key,
 				   void *buf, size_t buflen)
 {
-	if (strcmp(key, "") != 0)
-		return -EINVAL;
-
 	return nfs4_proc_get_acl(d_inode(dentry), buf, buflen);
 }
 
@@ -8834,7 +8828,7 @@ const struct nfs_rpc_ops nfs_v4_clientops = {
 };
 
 static const struct xattr_handler nfs4_xattr_nfs4_acl_handler = {
-	.prefix	= XATTR_NAME_NFSV4_ACL,
+	.name	= XATTR_NAME_NFSV4_ACL,
 	.list	= nfs4_xattr_list_nfs4_acl,
 	.get	= nfs4_xattr_get_nfs4_acl,
 	.set	= nfs4_xattr_set_nfs4_acl,