diff -up Linux-PAM-1.3.1/modules/pam_limits/limits.conf.5.xml.pam-limits-unlimited-value Linux-PAM-1.3.1/modules/pam_limits/limits.conf.5.xml --- Linux-PAM-1.3.1/modules/pam_limits/limits.conf.5.xml.pam-limits-unlimited-value 2022-01-28 09:45:41.431606850 +0100 +++ Linux-PAM-1.3.1/modules/pam_limits/limits.conf.5.xml 2022-01-28 09:47:31.732430391 +0100 @@ -275,6 +275,8 @@ All items support the values -1, unlimited or infinity indicating no limit, except for priority and nice. + If nofile is to be set to one of these values, + it will be set to the contents of /proc/sys/fs/nr_open instead (see setrlimit(3)). If a hard limit or soft limit of a resource is set to a valid value, diff -up Linux-PAM-1.3.1/modules/pam_limits/pam_limits.c.pam-limits-unlimited-value Linux-PAM-1.3.1/modules/pam_limits/pam_limits.c --- Linux-PAM-1.3.1/modules/pam_limits/pam_limits.c.pam-limits-unlimited-value 2022-01-28 09:45:41.415606731 +0100 +++ Linux-PAM-1.3.1/modules/pam_limits/pam_limits.c 2022-01-28 09:45:41.431606850 +0100 @@ -487,6 +487,41 @@ static int init_limits(pam_handle_t *pam return retval; } +/* + * Read the contents of and return it in *valuep + * return 1 if conversion succeeds, result is in *valuep + * return 0 if conversion fails, *valuep is untouched. + */ +static int +value_from_file(const char *pathname, rlim_t *valuep) +{ + char buf[128]; + FILE *fp; + int retval; + + retval = 0; + + if ((fp = fopen(pathname, "r")) != NULL) { + if (fgets(buf, sizeof(buf), fp) != NULL) { + char *endptr; + unsigned long long value; + + errno = 0; + value = strtoull(buf, &endptr, 10); + if (endptr != buf && + (value != ULLONG_MAX || errno == 0) && + (unsigned long long) (rlim_t) value == value) { + *valuep = (rlim_t) value; + retval = 1; + } + } + + fclose(fp); + } + + return retval; +} + static void process_limit (const pam_handle_t *pamh, int source, const char *lim_type, const char *lim_item, const char *lim_value, @@ -652,6 +687,20 @@ process_limit (const pam_handle_t *pamh, rlimit_value = 20 - int_value; break; #endif + case RLIMIT_NOFILE: + /* + * If nofile is to be set to "unlimited", try to set it to + * the value in /proc/sys/fs/nr_open instead. + */ + if (rlimit_value == RLIM_INFINITY) { + if (!value_from_file("/proc/sys/fs/nr_open", &rlimit_value)) + pam_syslog(pamh, LOG_WARNING, + "Cannot set \"nofile\" to a sensible value"); + else if (ctrl & PAM_DEBUG_ARG) + pam_syslog(pamh, LOG_DEBUG, "Setting \"nofile\" limit to %llu", + (unsigned long long) rlimit_value); + } + break; } if ( (limit_item != LIMIT_LOGIN)