Deal with remaining toctou defect (CID #1503910)

diff --git a/src/modules/rlm_sql/drivers/rlm_sql_sqlite/rlm_sql_sqlite.c b/src/modules/rlm_sql/drivers/rlm_sql_sqlite/rlm_sql_sqlite.c
index 2209253892c8ebc4b35350f65afe93a06e35a5dd..8300a1ba8eeb09b9d153189a9764d0405658039e 100644 (file)
--- a/src/modules/rlm_sql/drivers/rlm_sql_sqlite/rlm_sql_sqlite.c
+++ b/src/modules/rlm_sql/drivers/rlm_sql_sqlite/rlm_sql_sqlite.c
@@ -690,19 +690,28 @@ static int mod_bootstrap(module_inst_ctx_t const *mctx)
        rlm_sql_sqlite_t        *inst = talloc_get_type_abort(mctx->inst->data, rlm_sql_sqlite_t);
        bool                    exists;
        struct stat             buf;
+       int                     fd;
+       char const              *r;
 
        if (!inst->filename) {
                MEM(inst->filename = talloc_typed_asprintf(inst, "%s/%s",
                                                           main_config->raddb_dir, config->sql_db));
        }
 
-       /* coverity[fs_check_call] */
-       if (stat(inst->filename, &buf) == 0) {
+       /*
+        *      mod_bootstrap() will try to create the database if it doesn't exist, up to and
+        *      including creating the directory it should live in, in which case we get to call
+        *      fr_dirfd() again. Hence failing this first fr_dirfd() just means the database isn't there.
+        */
+       if (fr_dirfd(&fd, &r, inst->filename) < 0) {
+               exists = false;
+       } else if (fstatat(fd, r, &buf, 0) == 0) {
                exists = true;
        } else if (errno == ENOENT) {
                exists = false;
        } else {
                ERROR("Database exists, but couldn't be opened: %s", fr_syserror(errno));
+               close(fd);
                return -1;
        }
 
@@ -738,6 +747,7 @@ static int mod_bootstrap(module_inst_ctx_t const *mctx)
 
                        return -1;
                }
+               (void) fr_dirfd(&fd, &r, inst->filename);
 
                status = sqlite3_open_v2(inst->filename, &db, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL);
                if (!db) {
@@ -786,10 +796,11 @@ static int mod_bootstrap(module_inst_ctx_t const *mctx)
 
                if (ret < 0) {
                unlink:
-                       if ((unlink(inst->filename) < 0) && (errno != ENOENT)) {
+                       if ((unlinkat(fd, r, 0) < 0) && (errno != ENOENT)) {
                                ERROR("Error removing partially initialised database: %s",
                                      fr_syserror(errno));
                        }
+                       close(fd);
                        return -1;
                }
 #else
@@ -798,6 +809,7 @@ static int mod_bootstrap(module_inst_ctx_t const *mctx)
 #endif
        }
 
+       close(fd);
        return 0;
 }