Nagios Support Forum

--047d7b33dd70bb676904d9ee5b98
Content-Type: text/plain; charset=ISO-8859-1

This patch avoids a race condition in removal of lock files. The race
condition happens when:

1. we receive a SIGHUP, breaking us out of the event execution loop, and
2. receive a SIGTERM - or any other "shutdown" signal - AFTER checking for
the sigshutdown state but BEFORE the do-while loop terminates. I.e, during
execution of cleanup() or close_debug_log() towards the end of the loop.

Signed-off-by: Anton Lofgren
---
base/nagios.c | 15 +++++++++++----
base/utils.c | 1 -
2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/base/nagios.c b/base/nagios.c
index 6b834b2..806d355 100644
--- a/base/nagios.c
+++ b/base/nagios.c
@@ -539,6 +539,11 @@ int main(int argc, char **argv) {

/* keep monitoring things until we get a shutdown command */
do {
+ if (daemon_mode == TRUE && sigrestart == TRUE) {
+ /* if we've restarted in daemon mode, we don't want to
leak the
+ * lock file */
+ my_free(lock_file);
+ }

/* reset program variables */
reset_variables();
@@ -827,10 +832,6 @@ int main(int argc, char **argv) {
iobroker_destroy(nagios_iobs, IOBROKER_CLOSE_SOCKETS);
nagios_iobs = NULL;

- /* make sure lock file has been removed - it may not have
been if we received a shutdown command */
- if(daemon_mode == TRUE)
- unlink(lock_file);
-
/* log a shutdown message */
logit(NSLOG_PROCESS_INFO, TRUE, "Successfully shutdown...
(PID=%d)\n", (int)getpid());
}
@@ -844,6 +845,12 @@ int main(int argc, char **argv) {
}
while(sigrestart == TRUE && sigshutdown == FALSE);

+ /* make sure lock file has been removed - it may not have been if
we received a shutdown command */
+ if(daemon_mode == TRUE) {
+ unlink(lock_file);
+ my_free(lock_file);
+ }
+
/* free misc memory */
my_free(config_file);
}
diff --git a/base/utils.c b/base/utils.c
index af95663..1ff1e7b 100644
--- a/base/utils.c
+++ b/base/utils.c
@@ -3157,7 +3157,6 @@ void free_memory(nagios_macros *mac) {
my_free(temp_path);
my_free(check_result_path);
my_free(command_file);
- my_free(lock_file);
my_free(log_archive_path);

return;
--
1.8.2

--047d7b33dd70bb676904d9ee5b98
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

This patch avoids a=A0 race condition in removal of lock f=
iles. The racecondition happens when:1. we receive a SIGHUP, br=
eaking us out of the event execution loop, and2. receive a SIGTERM - or=
any other "shutdown" signal - AFTER checking for
the sigshutdown state but BEFORE the do-while loop terminates. I.e, duringexecution of cleanup() or close_debug_log() towards the end of the loop.=
Signed-off-by: Anton Lofgren <alofgren@op5.com>
---=A0base/nagios.c | 15 +++++++++++----=A0base/utils.c=A0 |=A0 1 -=
=A02 files changed, 11 insertions(+), 5 deletions(-)diff --git =
a/base/nagios.c b/base/nagios.cindex 6b834b2..806d355 100644--- a/b=
ase/nagios.c
+++ b/base/nagios.c@@ -539,6 +539,11 @@ int main(int argc, char **argv)=
{=A0=A0=A0=A0=A0 =A0=A0=A0 /* keep monitoring things until we get =
a shutdown command */=A0=A0=A0=A0 =A0=A0=A0 do {+=A0=A0=A0 =A0=A0=
=A0 =A0=A0=A0 if (daemon_mode =3D=3D TRUE && sigrestart =3D=3D TRUE=
) {
+=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 =A0=A0=A0 /* if we've restarted in daemo=
n mode, we don't want to leak the+=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 =A0=
=A0=A0 =A0* lock file */+=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 =A0=A0=A0 my_fre=
e(lock_file);+=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 }=A0=A0=A0=A0=A0 =
=A0=A0=A0 =A0=A0=A0 /* reset program variables */
=A0=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 reset_variables();@@ -827,10 +832,6 @@=
int main(int argc, char **argv) {=A0=A0=A0=A0 =A0=A0=A0 =A0=A0=A0 =A0=
=A0=A0 iobroker_destroy(nagios_iobs, IOBROKER_CLOSE_SOCKETS);=

...[email truncated]...


This post was automatically imported from historical nagios-devel mailing list archives
Original poster: alofgren@op5.com