From: Ralph Boehme <slow@samba.org>
Date: Thu, 23 Aug 2018 10:07:20 +0000 (+0200)
Subject: vfs_streams_xattr: fix open implementation
X-Git-Tag: tdb-1.3.17~1088
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9f58997d7a1ab0358963a45cb8bf291e7afa8068;p=thirdparty%2Fsamba.git

vfs_streams_xattr: fix open implementation

Since a long time the modules's open function happily returned success
when opening a non existent stream without O_CREAT.

This change fixes it to return -1 and errno=ENOATTR if

o get_ea_value() returns NT_STATUS_NOT_FOUND (eg mapped from
  getxattr() = -1, errno=ENOATTR) and

o flags doesn't contain O_CREAT

Bug: https://bugzilla.samba.org/show_bug.cgi?id=13646

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
---

diff --git a/source3/modules/vfs_streams_xattr.c b/source3/modules/vfs_streams_xattr.c
index 30459fec4bf..9f4bc13b034 100644
--- a/source3/modules/vfs_streams_xattr.c
+++ b/source3/modules/vfs_streams_xattr.c
@@ -412,6 +412,7 @@ static int streams_xattr_open(vfs_handle_struct *handle,
 	char *xattr_name = NULL;
 	int pipe_fds[2];
 	int fakefd = -1;
+	bool set_empty_xattr = false;
 	int ret;
 
 	SMB_VFS_HANDLE_GET_DATA(handle, config, struct streams_xattr_config,
@@ -445,39 +446,37 @@ static int streams_xattr_open(vfs_handle_struct *handle,
 		goto fail;
 	}
 
-	/*
-	 * Return a valid fd, but ensure any attempt to use it returns an error
-	 * (EPIPE).
-	 */
-	ret = pipe(pipe_fds);
-	if (ret != 0) {
-		goto fail;
-	}
-
-	close(pipe_fds[1]);
-	pipe_fds[1] = -1;
-	fakefd = pipe_fds[0];
-
 	status = get_ea_value(talloc_tos(), handle->conn, NULL,
 			      smb_fname, xattr_name, &ea);
 
 	DEBUG(10, ("get_ea_value returned %s\n", nt_errstr(status)));
 
-	if (!NT_STATUS_IS_OK(status)
-	    && !NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
-		/*
-		 * The base file is not there. This is an error even if we got
-		 * O_CREAT, the higher levels should have created the base
-		 * file for us.
-		 */
-		DEBUG(10, ("streams_xattr_open: base file %s not around, "
-			   "returning ENOENT\n", smb_fname->base_name));
-		errno = ENOENT;
-		goto fail;
+	if (!NT_STATUS_IS_OK(status)) {
+		if (!NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
+			/*
+			 * The base file is not there. This is an error even if
+			 * we got O_CREAT, the higher levels should have created
+			 * the base file for us.
+			 */
+			DBG_DEBUG("streams_xattr_open: base file %s not around, "
+				  "returning ENOENT\n", smb_fname->base_name);
+			errno = ENOENT;
+			goto fail;
+		}
+
+		if (!(flags & O_CREAT)) {
+			errno = ENOATTR;
+			goto fail;
+		}
+
+		set_empty_xattr = true;
 	}
 
-	if ((!NT_STATUS_IS_OK(status) && (flags & O_CREAT)) ||
-	    (flags & O_TRUNC)) {
+	if (flags & O_TRUNC) {
+		set_empty_xattr = true;
+	}
+
+	if (set_empty_xattr) {
 		/*
 		 * The attribute does not exist or needs to be truncated
 		 */
@@ -500,6 +499,19 @@ static int streams_xattr_open(vfs_handle_struct *handle,
 		}
 	}
 
+	/*
+	 * Return a valid fd, but ensure any attempt to use it returns an error
+	 * (EPIPE).
+	 */
+	ret = pipe(pipe_fds);
+	if (ret != 0) {
+		goto fail;
+	}
+
+	close(pipe_fds[1]);
+	pipe_fds[1] = -1;
+	fakefd = pipe_fds[0];
+
         sio = VFS_ADD_FSP_EXTENSION(handle, fsp, struct stream_io, NULL);
         if (sio == NULL) {
                 errno = ENOMEM;