Catch write errors when generating scriptlet temporary files

- If the write fails scripts are likely to fail anyway, but executing
  partial scriptlets (unlikely as that might be) could have funny
  side-effects besides just failing.
- Also cleans up runExtScript() a little bit by moving the
  tmp file creation to a separate function.

diff --git a/lib/rpmscript.c b/lib/rpmscript.c
index 3801873..e5ce8da 100644 (file)
--- a/lib/rpmscript.c
+++ b/lib/rpmscript.c
@@ -166,6 +166,30 @@ static void doScriptExec(int selinux, ARGV_const_t argv, ARGV_const_t prefixes,
     _exit(127); /* exit 127 for compatibility with bash(1) */
 }
 
+static char * writeScript(const char *cmd, const char *script)
+{
+    char *fn = NULL;
+    size_t slen = strlen(script);
+    int ok = 0;
+    FD_t fd = rpmMkTempFile("/", &fn);
+
+    if (Ferror(fd))
+       goto exit;
+
+    if (rpmIsDebug() && (rstreq(cmd, "/bin/sh") || rstreq(cmd, "/bin/bash"))) {
+       static const char set_x[] = "set -x\n";
+       /* Assume failures will be caught by the write below */
+       Fwrite(set_x, sizeof(set_x[0]), sizeof(set_x)-1, fd);
+    }
+
+    ok = (Fwrite(script, sizeof(script[0]), slen, fd) == slen);
+
+exit:
+    if (!ok) fn = _free(fn);
+    Fclose(fd);
+    return fn;
+}
+
 /**
  * Run an external script.
  */
@@ -185,23 +209,14 @@ static rpmRC runExtScript(int selinux, ARGV_const_t prefixes,
     rpmlog(RPMLOG_DEBUG, "%s: scriptlet start\n", sname);
 
     if (script) {
-       FD_t fd = rpmMkTempFile("/", &fn);
-       if (fd == NULL || Ferror(fd)) {
-           rpmlog(RPMLOG_ERR, _("Couldn't create temporary file for %s: %s\n"),
+       fn = writeScript(*argvp[0], script);
+       if (fn == NULL) {
+           rpmlog(RPMLOG_ERR,
+                  _("Couldn't create temporary file for %s: %s\n"),
                   sname, strerror(errno));
            goto exit;
        }
 
-       if (rpmIsDebug() &&
-           (rstreq(*argvp[0], "/bin/sh") || rstreq(*argvp[0], "/bin/bash")))
-       {
-           static const char set_x[] = "set -x\n";
-           xx = Fwrite(set_x, sizeof(set_x[0]), sizeof(set_x)-1, fd);
-       }
-
-       xx = Fwrite(script, sizeof(script[0]), strlen(script), fd);
-       xx = Fclose(fd);
-
        argvAdd(argvp, fn);
        if (arg1 >= 0) {
            argvAddNum(argvp, arg1);