psql: fix startup crash caused by PSQLRC containing a tilde

'strdup' the PSQLRC environment variable value before calling a routine
that might free() it.

Backpatch to 9.2, where the bug first appeared.

diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index be5e34a369a24f7b69ff1629dfdc5cedf74e3f93..3dea92c7d8f3bb6868754746f7cc1290713ca885 100644 (file)
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -1645,11 +1645,11 @@ session_username(void)
  * substitute '~' with HOME or '~username' with username's home dir
  *
  */
-char *
+void
 expand_tilde(char **filename)
 {
        if (!filename || !(*filename))
-               return NULL;
+               return;
 
        /*
         * WIN32 doesn't use tilde expansion for file names. Also, it uses tilde
@@ -1697,5 +1697,5 @@ expand_tilde(char **filename)
        }
 #endif
 
-       return *filename;
+       return;
 }

diff --git a/src/bin/psql/common.h b/src/bin/psql/common.h
index d8bb0930b415bb58caa158533568a50c5ba07456..db645dafabb4ee4c22d61cf946a7cd4eca8c31d0 100644 (file)
--- a/src/bin/psql/common.h
+++ b/src/bin/psql/common.h
@@ -44,6 +44,6 @@ extern bool is_superuser(void);
 extern bool standard_strings(void);
 extern const char *session_username(void);
 
-extern char *expand_tilde(char **filename);
+extern void expand_tilde(char **filename);
 
 #endif   /* COMMON_H */

diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 5cb6b5f364866f08e8178f12cb578b1805b525f0..5d7fe6ea27f46c38fe7de72db39058ee3ac09640 100644 (file)
--- a/src/bin/psql/startup.c
+++ b/src/bin/psql/startup.c
@@ -610,7 +610,7 @@ process_psqlrc(char *argv0)
        char            rc_file[MAXPGPATH];
        char            my_exec_path[MAXPGPATH];
        char            etc_path[MAXPGPATH];
-       char       *envrc;
+       char       *envrc = getenv("PSQLRC");
 
        find_my_exec(argv0, my_exec_path);
        get_etc_path(my_exec_path, etc_path);
@@ -618,12 +618,13 @@ process_psqlrc(char *argv0)
        snprintf(rc_file, MAXPGPATH, "%s/%s", etc_path, SYSPSQLRC);
        process_psqlrc_file(rc_file);
 
-       envrc = getenv("PSQLRC");
-
        if (envrc != NULL && strlen(envrc) > 0)
        {
-               expand_tilde(&envrc);
-               process_psqlrc_file(envrc);
+               /* might need to free() this */
+               char *envrc_alloc = pstrdup(envrc);
+
+               expand_tilde(&envrc_alloc);
+               process_psqlrc_file(envrc_alloc);
        }
        else if (get_home_path(home))
        {