From a045ef8abc1c81ac359103ac61841bae860d8960 Mon Sep 17 00:00:00 2001
From: "Jose M. Guisado Gomez" <guigom@riseup.net>
Date: Fri, 16 Aug 2019 11:25:11 +0200
Subject: [PATCH] src: fix strncpy -Wstringop-truncation warnings
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-Wstringop-truncation warning was introduced in GCC-8 as truncation
checker for strncpy and strncat.
Systems using gcc version >= 8 would receive the following warnings:
read_config_yy.c: In function ‘yyparse’:
read_config_yy.y:1594:2: warning: ‘strncpy’ specified bound 16 equals destination size [-Wstringop-truncation]
1594 | strncpy(policy->name, $2, CTD_HELPER_NAME_LEN);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
read_config_yy.y:1384:2: warning: ‘strncpy’ specified bound 256 equals destination size [-Wstringop-truncation]
1384 | strncpy(conf.stats.logfile, $2, FILENAME_MAXLEN);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
read_config_yy.y:692:2: warning: ‘strncpy’ specified bound 108 equals destination size [-Wstringop-truncation]
692 | strncpy(conf.local.path, $2, UNIX_PATH_MAX);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
read_config_yy.y:169:2: warning: ‘strncpy’ specified bound 256 equals destination size [-Wstringop-truncation]
169 | strncpy(conf.lockfile, $2, FILENAME_MAXLEN);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
read_config_yy.y:119:2: warning: ‘strncpy’ specified bound 256 equals destination size [-Wstringop-truncation]
119 | strncpy(conf.logfile, $2, FILENAME_MAXLEN);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
main.c: In function ‘main’:
main.c:168:5: warning: ‘strncpy’ specified bound 4096 equals destination size [-Wstringop-truncation]
168 | strncpy(config_file, argv[i], PATH_MAX);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix the issue by checking for string length first. Also using
snprintf instead.
In addition, correct an off-by-one when warning about maximum config
file path length.
Signed-off-by: Jose M. Guisado Gomez <guigom@riseup.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(cherry picked from commit f196de88cdd9764ddc2e4de737a960972d82fe9d)
---
include/conntrackd.h | 6 +++---
include/helper.h | 2 +-
include/local.h | 4 ++--
src/main.c | 7 +++----
src/read_config_yy.y | 39 +++++++++++++++++++++++++++++----------
5 files changed, 38 insertions(+), 20 deletions(-)
diff --git a/include/conntrackd.h b/include/conntrackd.h
index 81dff221e96de..fe9ec1854a7d2 100644
--- a/include/conntrackd.h
+++ b/include/conntrackd.h
@@ -85,9 +85,9 @@ union inet_address {
#define CONFIG(x) conf.x
struct ct_conf {
- char logfile[FILENAME_MAXLEN];
+ char logfile[FILENAME_MAXLEN + 1];
int syslog_facility;
- char lockfile[FILENAME_MAXLEN];
+ char lockfile[FILENAME_MAXLEN + 1];
int hashsize; /* hashtable size */
int channel_num;
int channel_default;
@@ -132,7 +132,7 @@ struct ct_conf {
int prio;
} sched;
struct {
- char logfile[FILENAME_MAXLEN];
+ char logfile[FILENAME_MAXLEN + 1];
int syslog_facility;
size_t buffer_size;
} stats;
diff --git a/include/helper.h b/include/helper.h
index 7353dfa9b2073..08d4cf4642802 100644
--- a/include/helper.h
+++ b/include/helper.h
@@ -13,7 +13,7 @@ struct pkt_buff;
#define CTD_HELPER_POLICY_MAX 4
struct ctd_helper_policy {
- char name[CTD_HELPER_NAME_LEN];
+ char name[CTD_HELPER_NAME_LEN + 1];
uint32_t expect_timeout;
uint32_t expect_max;
};
diff --git a/include/local.h b/include/local.h
index 22859d7ab60aa..9379446732eed 100644
--- a/include/local.h
+++ b/include/local.h
@@ -7,12 +7,12 @@
struct local_conf {
int reuseaddr;
- char path[UNIX_PATH_MAX];
+ char path[UNIX_PATH_MAX + 1];
};
struct local_server {
int fd;
- char path[UNIX_PATH_MAX];
+ char path[UNIX_PATH_MAX + 1];
};
/* callback return values */
diff --git a/src/main.c b/src/main.c
index 8c3fa1c943a96..de4773df8a204 100644
--- a/src/main.c
+++ b/src/main.c
@@ -120,8 +120,8 @@ do_chdir(const char *d)
int main(int argc, char *argv[])
{
+ char config_file[PATH_MAX + 1] = {};
int ret, i, action = -1;
- char config_file[PATH_MAX] = {};
int type = 0;
struct utsname u;
int version, major, minor;
@@ -165,13 +165,12 @@ int main(int argc, char *argv[])
break;
case 'C':
if (++i < argc) {
- strncpy(config_file, argv[i], PATH_MAX);
- if (strlen(argv[i]) >= PATH_MAX){
- config_file[PATH_MAX-1]='\0';
+ if (strlen(argv[i]) > PATH_MAX) {
dlog(LOG_WARNING, "Path to config file"
" to long. Cutting it down to %d"
" characters", PATH_MAX);
}
+ snprintf(config_file, PATH_MAX, "%s", argv[i]);
break;
}
show_usage(argv[0]);
diff --git a/src/read_config_yy.y b/src/read_config_yy.y
index 6aee67623953b..d963c494be1fc 100644
--- a/src/read_config_yy.y
+++ b/src/read_config_yy.y
@@ -116,7 +116,12 @@ logfile_bool : T_LOG T_OFF
logfile_path : T_LOG T_PATH_VAL
{
- strncpy(conf.logfile, $2, FILENAME_MAXLEN);
+ if (strlen($2) > FILENAME_MAXLEN) {
+ dlog(LOG_ERR, "LogFile path is longer than %u characters",
+ FILENAME_MAXLEN);
+ exit(EXIT_FAILURE);
+ }
+ snprintf(conf.logfile, FILENAME_MAXLEN, "%s", $2);
free($2);
};
@@ -166,7 +171,12 @@ syslog_facility : T_SYSLOG T_STRING
lock : T_LOCK T_PATH_VAL
{
- strncpy(conf.lockfile, $2, FILENAME_MAXLEN);
+ if (strlen($2) > FILENAME_MAXLEN) {
+ dlog(LOG_ERR, "LockFile path is longer than %u characters",
+ FILENAME_MAXLEN);
+ exit(EXIT_FAILURE);
+ }
+ snprintf(conf.lockfile, FILENAME_MAXLEN, "%s", $2);
free($2);
};
@@ -689,13 +699,13 @@ unix_options:
unix_option : T_PATH T_PATH_VAL
{
- strncpy(conf.local.path, $2, UNIX_PATH_MAX);
- free($2);
- if (conf.local.path[UNIX_PATH_MAX - 1]) {
- dlog(LOG_ERR, "UNIX Path is longer than %u characters",
- UNIX_PATH_MAX - 1);
+ if (strlen($2) > UNIX_PATH_MAX) {
+ dlog(LOG_ERR, "Path is longer than %u characters",
+ UNIX_PATH_MAX);
exit(EXIT_FAILURE);
}
+ snprintf(conf.local.path, UNIX_PATH_MAX, "%s", $2);
+ free($2);
};
unix_option : T_BACKLOG T_NUMBER
@@ -1381,7 +1391,12 @@ stat_logfile_bool : T_LOG T_OFF
stat_logfile_path : T_LOG T_PATH_VAL
{
- strncpy(conf.stats.logfile, $2, FILENAME_MAXLEN);
+ if (strlen($2) > FILENAME_MAXLEN) {
+ dlog(LOG_ERR, "stats LogFile path is longer than %u characters",
+ FILENAME_MAXLEN);
+ exit(EXIT_FAILURE);
+ }
+ snprintf(conf.stats.logfile, FILENAME_MAXLEN, "%s", $2);
free($2);
};
@@ -1589,11 +1604,15 @@ helper_type: T_HELPER_POLICY T_STRING '{' helper_policy_list '}'
exit(EXIT_FAILURE);
break;
}
+ if (strlen($2) > CTD_HELPER_NAME_LEN) {
+ dlog(LOG_ERR, "Helper Policy is longer than %u characters",
+ CTD_HELPER_NAME_LEN);
+ exit(EXIT_FAILURE);
+ }
policy = (struct ctd_helper_policy *) &e->data;
- strncpy(policy->name, $2, CTD_HELPER_NAME_LEN);
+ snprintf(policy->name, CTD_HELPER_NAME_LEN, "%s", $2);
free($2);
- policy->name[CTD_HELPER_NAME_LEN-1] = '\0';
/* Now object is complete. */
e->type = SYMBOL_HELPER_POLICY_EXPECT_ROOT;
stack_item_push(&symbol_stack, e);
--
2.34.1