From 01cd2d15a9bf1109e0e71b3e31b835d63dcf9cd8 Mon Sep 17 00:00:00 2001 From: Maxime Devos , Yin Kangkai , Sudip Mukherjee Subject: [PATCH] Fix segfault when run as normal user Also exit immediately when "restartd -h" Signed-off-by: Yin Kangkai Fix build with gcc-10 Bug: https://bugs.debian.org/957761 Signed-off-by: Sudip Mukherjee Handle memory allocation failures. This makes the code a little more robust. Signed-off-by: Maxime Devos Handle fopen failures. This makes the code a little more robust. What if /var/run does not exist, or we do not have permission to open /var/run/restartd.pid (EPERM?) due to SELinux misconfiguration? Signed-off-by: Maxime Devos Handle printf and fprintf failures. This makes the code a little more robust. What if the write was refused to the underlying device being removed? The --help, debug and stderr printfs were ignored because there error handling does not appear important to me. Signed-off-by: Maxime Devos Handle fclose failures when writing. This makes the code a little more robust. What if a quotum is exceeded? Signed-off-by: Maxime Devos --- config.c | 19 +++++++++---- config.h | 14 ++++++---- restartd.c | 80 +++++++++++++++++++++++++++++++++++++++++++++++------- 3 files changed, 92 insertions(+), 21 deletions(-) diff --git a/config.c b/config.c index f307b8a..5cc0271 100644 --- a/config.c +++ b/config.c @@ -57,7 +57,11 @@ int read_config(void) config_process_number = 0; line1 = (char *) malloc(MAX_LINE_LENGTH); + if (!line1) + oom_failure(); line2 = (char *) malloc(MAX_LINE_LENGTH); + if (!line2) + oom_failure(); if ((config_fd = fopen(config_file, "rt")) == NULL) { fprintf(stderr, "Error at opening config file: %s\n", config_file); @@ -155,11 +159,16 @@ void dump_config(void) { int i; for(i=0; i * Copyright (C) 2006 Aurélien GÉRÔME + * Copyright (C) 2022 Maxime Devos * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -25,12 +26,12 @@ #define DEFAULT_CONFIG "/etc/restartd.conf" -int debug; -int config_process_number; -int check_interval; -int foreground; -struct config_process_type *config_process; -char *config_file; +extern int debug; +extern int config_process_number; +extern int check_interval; +extern int foreground; +extern struct config_process_type *config_process; +extern char *config_file; typedef struct config_process_type { char name[64]; @@ -43,5 +44,6 @@ typedef struct config_process_type { int read_config(/* char *config_file */); void dump_config(void); +void oom_failure(void); #endif /* RESTARTD_CONFIG_H */ diff --git a/restartd.c b/restartd.c index 2aa720c..aa74334 100644 --- a/restartd.c +++ b/restartd.c @@ -1,6 +1,7 @@ /* restartd - Process checker and/or restarter daemon * Copyright (C) 2000-2002 Tibor Koleszar * Copyright (C) 2006 Aurélien GÉRÔME + * Copyright (C) 2022 Maxime Devos * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License @@ -35,6 +36,13 @@ #include "config.h" +int debug; +int config_process_number; +int check_interval; +int foreground; +struct config_process_type *config_process; +char *config_file; + /* SIGTERM & SIGHUP handler */ void got_signal(int sig) { @@ -52,6 +60,17 @@ void got_signal(int sig) } } +/* Ignoring out-of-memory failures is risky on systems without virtual memory + where additionally at address 0 there is actually something important + mapped. Additionally, while often on Linux the OOM killer will kill processes + where an OOM happens, this is not always the case and there exist other systems + without an OOM killer (e.g. the Hurd). */ +void oom_failure() +{ + syslog(LOG_ERR, "Failed to allocate memory. Exiting."); + exit(1); +} + int main(int argc, char *argv[]) { DIR *procdir_id; @@ -75,15 +94,21 @@ int main(int argc, char *argv[]) /* Options */ config_file = strdup(DEFAULT_CONFIG); + if (!config_file) + oom_failure(); + list_only = 0; for(i = 0; i < argc; i++) { if (!strcmp(argv[i], "-c") || !strcmp(argv[i], "--config")) { config_file = strdup(argv[i + 1]); + if (!config_file) + oom_failure(); } if (!strcmp(argv[i], "-v") || !strcmp(argv[i], "--version")) { printf("restard %s - Copyright 2000-2002 Tibor Koleszar \n" - " Copyright 2006 Aurélien GÉRÔME \n", + " Copyright 2006 Aurélien GÉRÔME \n" + " Copyright 2022 Maxime Devos \n", VERSION); exit(0); } @@ -118,10 +143,13 @@ int main(int argc, char *argv[]) " -i : the check interval in second\n" " -l : list configuration options\n" " -h : help\n\n", VERSION); + exit(0); } } config_process = malloc(sizeof(struct config_process_type) * 128); + if (!config_process) + oom_failure(); read_config(); if (list_only) { @@ -133,9 +161,17 @@ int main(int argc, char *argv[]) config_process_number); procdir_dirent = malloc(sizeof(struct dirent)); + if (!procdir_dirent) + oom_failure(); proc_cmdline_str = (char *) malloc(1024); + if (!proc_cmdline_str) + oom_failure(); proc_cmdline_name = (char *) malloc(1024); + if (!proc_cmdline_name) + oom_failure(); regc = malloc(1024); + if (!regc) + oom_failure(); /* Catch signals */ signal(SIGTERM, got_signal); @@ -187,8 +223,19 @@ int main(int argc, char *argv[]) } out_proc = fopen("/var/run/restartd.pid", "wt"); - fprintf(out_proc, "%d", getpid()); - fclose(out_proc); + if (!out_proc) { + syslog(LOG_ERR, "Failed to open /var/run/restartd.pid"); + return -1; + } + if (fprintf(out_proc, "%d", getpid()) < 0) { + syslog(LOG_ERR, "Failed to write to /var/run/restartd.pid. Exiting."); + return -1; + } + if (fclose(out_proc) < 0) { /* errors can happen when flushing the buffer */ + syslog(LOG_ERR, "Failed to write to /var/run/restartd.pid. Exiting."); + return -1; + } + while(1) { if ((procdir_id = opendir("/proc")) == NULL) { @@ -237,16 +284,23 @@ int main(int argc, char *argv[]) now = time(NULL); out_proc = fopen("/var/run/restartd", "wt"); + if (!out_proc) { + syslog(LOG_ERR, "Failed to open /var/run/restartd.pid"); + return -1; + } - fprintf(out_proc, "%s\n", ctime(&now)); + if (fprintf(out_proc, "%s\n", ctime(&now)) < 0) { + syslog(LOG_ERR, "Failed to write to /var/run/restartd. Exiting."); + return -1; + } for(i=0; i 0) { if (strlen(config_process[i].running) > 0) { strcpy(config_process[i].status, "running"); - syslog(LOG_INFO, "%s is running, executing '%s'", + /* syslog(LOG_INFO, "%s is running, executing '%s'", config_process[i].name, - config_process[i].running); + config_process[i].running); */ system(config_process[i].running); } else { strcpy(config_process[i].status, "running"); @@ -267,12 +321,18 @@ int main(int argc, char *argv[]) strcpy(config_process[i].status, "not running"); } - fprintf(out_proc, "%-12s %-12s %s\n", - config_process[i].name, config_process[i].status, - config_process[i].processes); + if (fprintf(out_proc, "%-12s %-12s %s\n", + config_process[i].name, config_process[i].status, + config_process[i].processes) < 0) { + syslog(LOG_ERR, "Failed to write to /var/run/restartd. Exiting."); + return -1; + } } - fclose(out_proc); + if (fclose(out_proc) < 0) { + syslog(LOG_ERR, "Failed to write to /var/run/restartd.pid. Exiting."); + return -1; + } sleep(check_interval); } -- 2.37.3