diff --git a/login-utils/su-common.c b/login-utils/su-common.c
index c8eb6cf05..02687892c 100644
--- a/login-utils/su-common.c
+++ b/login-utils/su-common.c
@@ -959,13 +959,27 @@ static int is_not_root(void)
 	return (uid_t) 0 == ruid && ruid == euid ? 0 : 1;
 }
 
+/* Don't rely on PAM and reset the most important limits. */
 static void sanitize_prlimits(void)
 {
 #ifdef HAVE_SYS_RESOURCE_H
 	struct rlimit lm = { .rlim_cur = 0, .rlim_max = 0 };
 
+	/* reset to zero */
 	setrlimit(RLIMIT_NICE, &lm);
 	setrlimit(RLIMIT_RTPRIO, &lm);
+
+	/* reset to unlimited */
+	lm.rlim_cur = RLIM_INFINITY;
+	lm.rlim_max = RLIM_INFINITY;
+	setrlimit(RLIMIT_FSIZE, &lm);
+
+	/* reset soft limit only */
+	getrlimit(RLIMIT_NOFILE, &lm);
+	if (lm.rlim_cur != FD_SETSIZE) {
+		lm.rlim_cur = FD_SETSIZE;
+		setrlimit(RLIMIT_NOFILE, &lm);
+	}
 #endif
 }
 
diff --git a/login-utils/su.1.adoc b/login-utils/su.1.adoc
index add7fbb52..9c9f77271 100644
--- a/login-utils/su.1.adoc
+++ b/login-utils/su.1.adoc
@@ -29,7 +29,7 @@ This version of *su* uses PAM for authentication, account and session management
 
 Note that *su* in all cases uses PAM (*pam_getenvlist*(3)) to do the final environment modification. Command-line options such as *--login* and *--preserve-environment* affect the environment before it is modified by PAM.
 
-Since version 2.38 *su* resets process resource limits RLIMIT_NICE and RLIMIT_RTPRIO to zero.
+Since version 2.38 *su* resets process resource limits RLIMIT_NICE, RLIMIT_RTPRIO, RLIMIT_FSIZE and RLIMIT_NOFILE.
 
 == OPTIONS