su: reset RLIMIT_{NICE,RTPRIO} to zero

Addresses: https://github.com/linux-pam/linux-pam/issues/85
Reported-by: Lennart Poettering <lennart@poettering.net>
Signed-off-by: Karel Zak <kzak@redhat.com>

diff --git a/login-utils/runuser.1.adoc b/login-utils/runuser.1.adoc
index ecbc39c34a3bd18a3f7cb8bf0baa91402f2a214e..f2ca6fc326ca971d5d5d4619158b84e62f848534 100644 (file)
--- a/login-utils/runuser.1.adoc
+++ b/login-utils/runuser.1.adoc
@@ -28,6 +28,8 @@ For backward compatibility, *runuser* defaults to not changing the current direc
 
 Note that *runuser* in all cases use PAM (pam_getenvlist()) 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 *runuser* resets process resource limits RLIMIT_NICE and RLIMIT_RTPRIO to zero.
+
 == OPTIONS
 
 *-c*, *--command*=_command_::

diff --git a/login-utils/su-common.c b/login-utils/su-common.c
index afd0ea8ad5f05fc9a190e56fc78cc4e8c4343dcd..c8eb6cf051347bd965d7e2b9ad663c42f64fe02a 100644 (file)
--- a/login-utils/su-common.c
+++ b/login-utils/su-common.c
@@ -36,6 +36,11 @@
 #include <sys/wait.h>
 #include <syslog.h>
 #include <utmpx.h>
+#include <sys/time.h>
+
+#ifdef HAVE_SYS_RESOURCE_H
+# include <sys/resource.h>
+#endif
 
 #ifdef HAVE_PTY
 # include <pty.h>
@@ -954,6 +959,16 @@ static int is_not_root(void)
        return (uid_t) 0 == ruid && ruid == euid ? 0 : 1;
 }
 
+static void sanitize_prlimits(void)
+{
+#ifdef HAVE_SYS_RESOURCE_H
+       struct rlimit lm = { .rlim_cur = 0, .rlim_max = 0 };
+
+       setrlimit(RLIMIT_NICE, &lm);
+       setrlimit(RLIMIT_RTPRIO, &lm);
+#endif
+}
+
 static gid_t add_supp_group(const char *name, gid_t **groups, size_t *ngroups)
 {
        struct group *gr;
@@ -1195,6 +1210,8 @@ int su_main(int argc, char **argv, int mode)
        if (!su->simulate_login || command)
                su->suppress_pam_info = 1;      /* don't print PAM info messages */
 
+       sanitize_prlimits();
+
        supam_open_session(su);
 
 #ifdef USE_PTY

diff --git a/login-utils/su.1.adoc b/login-utils/su.1.adoc
index 132c90578e150f40beb42be7248db82cdb3e36d7..add7fbb5229f6c36fec5da08a63a9b237fac3ba9 100644 (file)
--- a/login-utils/su.1.adoc
+++ b/login-utils/su.1.adoc
@@ -29,6 +29,8 @@ 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.
+
 == OPTIONS
 
 *-c*, **--command**=__command__::