Fix RLS with COPY (col1, col2) FROM tab

Attempting to COPY a subset of columns from a table with RLS enabled
would fail due to an invalid query being constructed (using a single
ColumnRef with the list of fields to exact in 'fields', but that's for
the different levels of an indirection for a single column, not for
specifying multiple columns).

Correct by building a ColumnRef and then RestTarget for each column
being requested and then adding those to the targetList for the select
query.  Include regression tests to hopefully catch if this is broken
again in the future.

Patch-By: Adam Brightwell
Reviewed-By: Michael Paquier

diff --git a/src/backend/commands/copy.c b/src/backend/commands/copy.c
index 432b0ca67ba57a7b506a4be0f8a3bc15cd24904a..457c9bbd74b91fd60f19566e069d19a02bbf6852 100644 (file)
--- a/src/backend/commands/copy.c
+++ b/src/backend/commands/copy.c
@@ -871,6 +871,7 @@ DoCopy(ParseState *pstate, const CopyStmt *stmt, uint64 *processed)
                        ColumnRef  *cr;
                        ResTarget  *target;
                        RangeVar   *from;
+                       List       *targetList = NIL;
 
                        if (is_from)
                                ereport(ERROR,
@@ -878,21 +879,59 @@ DoCopy(ParseState *pstate, const CopyStmt *stmt, uint64 *processed)
                                   errmsg("COPY FROM not supported with row-level security"),
                                                 errhint("Use INSERT statements instead.")));
 
-                       /* Build target list */
-                       cr = makeNode(ColumnRef);
-
+                       /*
+                        * Build target list
+                        *
+                        * If no columns are specified in the attribute list of the COPY
+                        * command, then the target list is 'all' columns. Therefore, '*'
+                        * should be used as the target list for the resulting SELECT
+                        * statement.
+                        *
+                        * In the case that columns are specified in the attribute list,
+                        * create a ColumnRef and ResTarget for each column and add them to
+                        * the target list for the resulting SELECT statement.
+                        */
                        if (!stmt->attlist)
+                       {
+                               cr = makeNode(ColumnRef);
                                cr->fields = list_make1(makeNode(A_Star));
-                       else
-                               cr->fields = stmt->attlist;
+                               cr->location = -1;
+
+                               target = makeNode(ResTarget);
+                               target->name = NULL;
+                               target->indirection = NIL;
+                               target->val = (Node *) cr;
+                               target->location = -1;
 
-                       cr->location = 1;
+                               targetList = list_make1(target);
+                       }
+                       else
+                       {
+                               ListCell   *lc;
 
-                       target = makeNode(ResTarget);
-                       target->name = NULL;
-                       target->indirection = NIL;
-                       target->val = (Node *) cr;
-                       target->location = 1;
+                               foreach(lc, stmt->attlist)
+                               {
+                                       /*
+                                        * Build the ColumnRef for each column.  The ColumnRef
+                                        * 'fields' property is a String 'Value' node (see
+                                        * nodes/value.h) that corresponds to the column name
+                                        * respectively.
+                                        */
+                                       cr = makeNode(ColumnRef);
+                                       cr->fields = list_make1(lfirst(lc));
+                                       cr->location = -1;
+
+                                       /* Build the ResTarget and add the ColumnRef to it. */
+                                       target = makeNode(ResTarget);
+                                       target->name = NULL;
+                                       target->indirection = NIL;
+                                       target->val = (Node *) cr;
+                                       target->location = -1;
+
+                                       /* Add each column to the SELECT statement's target list */
+                                       targetList = lappend(targetList, target);
+                               }
+                       }
 
                        /*
                         * Build RangeVar for from clause, fully qualified based on the
@@ -903,7 +942,7 @@ DoCopy(ParseState *pstate, const CopyStmt *stmt, uint64 *processed)
 
                        /* Build query */
                        select = makeNode(SelectStmt);
-                       select->targetList = list_make1(target);
+                       select->targetList = targetList;
                        select->fromClause = list_make1(from);
 
                        query = (Node *) select;

diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
index 5f6260a8f1b1bf6b1655b1329d9a30bf27d185b0..b3c215cf287011ba42e11bcb4db45e5fb545fb13 100644 (file)
--- a/src/test/regress/expected/copy2.out
+++ b/src/test/regress/expected/copy2.out
@@ -460,9 +460,87 @@ select * from check_con_tbl;
    
 (2 rows)
 
+-- test with RLS enabled.
+CREATE ROLE regress_rls_copy_user;
+CREATE ROLE regress_rls_copy_user_colperms;
+CREATE TABLE rls_t1 (a int, b int, c int);
+COPY rls_t1 (a, b, c) from stdin;
+CREATE POLICY p1 ON rls_t1 FOR SELECT USING (a % 2 = 0);
+ALTER TABLE rls_t1 ENABLE ROW LEVEL SECURITY;
+ALTER TABLE rls_t1 FORCE ROW LEVEL SECURITY;
+GRANT SELECT ON TABLE rls_t1 TO regress_rls_copy_user;
+GRANT SELECT (a, b) ON TABLE rls_t1 TO regress_rls_copy_user_colperms;
+-- all columns
+COPY rls_t1 TO stdout;
+1      4       1
+2      3       2
+3      2       3
+4      1       4
+COPY rls_t1 (a, b, c) TO stdout;
+1      4       1
+2      3       2
+3      2       3
+4      1       4
+-- subset of columns
+COPY rls_t1 (a) TO stdout;
+1
+2
+3
+4
+COPY rls_t1 (a, b) TO stdout;
+1      4
+2      3
+3      2
+4      1
+-- column reordering
+COPY rls_t1 (b, a) TO stdout;
+4      1
+3      2
+2      3
+1      4
+SET SESSION AUTHORIZATION regress_rls_copy_user;
+-- all columns
+COPY rls_t1 TO stdout;
+2      3       2
+4      1       4
+COPY rls_t1 (a, b, c) TO stdout;
+2      3       2
+4      1       4
+-- subset of columns
+COPY rls_t1 (a) TO stdout;
+2
+4
+COPY rls_t1 (a, b) TO stdout;
+2      3
+4      1
+-- column reordering
+COPY rls_t1 (b, a) TO stdout;
+3      2
+1      4
+RESET SESSION AUTHORIZATION;
+SET SESSION AUTHORIZATION regress_rls_copy_user_colperms;
+-- attempt all columns (should fail)
+COPY rls_t1 TO stdout;
+ERROR:  permission denied for relation rls_t1
+COPY rls_t1 (a, b, c) TO stdout;
+ERROR:  permission denied for relation rls_t1
+-- try to copy column with no privileges (should fail)
+COPY rls_t1 (c) TO stdout;
+ERROR:  permission denied for relation rls_t1
+-- subset of columns (should succeed)
+COPY rls_t1 (a) TO stdout;
+2
+4
+COPY rls_t1 (a, b) TO stdout;
+2      3
+4      1
+RESET SESSION AUTHORIZATION;
 DROP TABLE forcetest;
 DROP TABLE vistest;
 DROP FUNCTION truncate_in_subxact();
 DROP TABLE x, y;
+DROP TABLE rls_t1 CASCADE;
+DROP ROLE regress_rls_copy_user;
+DROP ROLE regress_rls_copy_user_colperms;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();

diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
index 39a9deb8f78369a2a194bb029355917ce272b269..89d0a39eb9d9a25ba7fb3aedd0134e3d6cff4d21 100644 (file)
--- a/src/test/regress/sql/copy2.sql
+++ b/src/test/regress/sql/copy2.sql
@@ -327,9 +327,72 @@ copy check_con_tbl from stdin;
 \.
 select * from check_con_tbl;
 
+-- test with RLS enabled.
+CREATE ROLE regress_rls_copy_user;
+CREATE ROLE regress_rls_copy_user_colperms;
+CREATE TABLE rls_t1 (a int, b int, c int);
+
+COPY rls_t1 (a, b, c) from stdin;
+1      4       1
+2      3       2
+3      2       3
+4      1       4
+\.
+
+CREATE POLICY p1 ON rls_t1 FOR SELECT USING (a % 2 = 0);
+ALTER TABLE rls_t1 ENABLE ROW LEVEL SECURITY;
+ALTER TABLE rls_t1 FORCE ROW LEVEL SECURITY;
+
+GRANT SELECT ON TABLE rls_t1 TO regress_rls_copy_user;
+GRANT SELECT (a, b) ON TABLE rls_t1 TO regress_rls_copy_user_colperms;
+
+-- all columns
+COPY rls_t1 TO stdout;
+COPY rls_t1 (a, b, c) TO stdout;
+
+-- subset of columns
+COPY rls_t1 (a) TO stdout;
+COPY rls_t1 (a, b) TO stdout;
+
+-- column reordering
+COPY rls_t1 (b, a) TO stdout;
+
+SET SESSION AUTHORIZATION regress_rls_copy_user;
+
+-- all columns
+COPY rls_t1 TO stdout;
+COPY rls_t1 (a, b, c) TO stdout;
+
+-- subset of columns
+COPY rls_t1 (a) TO stdout;
+COPY rls_t1 (a, b) TO stdout;
+
+-- column reordering
+COPY rls_t1 (b, a) TO stdout;
+
+RESET SESSION AUTHORIZATION;
+
+SET SESSION AUTHORIZATION regress_rls_copy_user_colperms;
+
+-- attempt all columns (should fail)
+COPY rls_t1 TO stdout;
+COPY rls_t1 (a, b, c) TO stdout;
+
+-- try to copy column with no privileges (should fail)
+COPY rls_t1 (c) TO stdout;
+
+-- subset of columns (should succeed)
+COPY rls_t1 (a) TO stdout;
+COPY rls_t1 (a, b) TO stdout;
+
+RESET SESSION AUTHORIZATION;
+
 DROP TABLE forcetest;
 DROP TABLE vistest;
 DROP FUNCTION truncate_in_subxact();
 DROP TABLE x, y;
+DROP TABLE rls_t1 CASCADE;
+DROP ROLE regress_rls_copy_user;
+DROP ROLE regress_rls_copy_user_colperms;
 DROP FUNCTION fn_x_before();
 DROP FUNCTION fn_x_after();