Re: Memory leak in adjust_data_dir

On Wed, 16 Nov 2022 at 12:19, Tom Lane <tgl@sss.pgh.pa.us> wrote:

Japin Li <japinli@hotmail.com> writes:

Hi, hackers,

ITYM pgsql-hackers, this is off-topic here.

Sorry for typo the email address.

When I'm reviewing patch [1], I find there is a memory leak in
adjust_data_dir(), the cmd was allocated by psprintf(), but forget
releasing.

Can't get excited about it in pg_ctl; that program won't run
long enough for anybody to notice.

Yeah, it won't run a long time. I find that the memory of my_exec_path
was released, so I think we also should do release on cmd. IMO, this is
a bit confused when should we do release the memory of variables for
short lifetime?

[Here is the origin contents which I send a wrong mail-list]

Hi, hackers,

When I'm reviewing patch [1]/messages/by-id/CALte62y3yZpHNFnYVz1uACaFbmb6go9fyeRaO5uHF5XaxtarbA@mail.gmail.com, I find there is a memory leak in
adjust_data_dir(), the cmd was allocated by psprintf(), but forget
releasing.

[1]: /messages/by-id/CALte62y3yZpHNFnYVz1uACaFbmb6go9fyeRaO5uHF5XaxtarbA@mail.gmail.com

diff --git a/src/bin/pg_ctl/pg_ctl.c b/src/bin/pg_ctl/pg_ctl.c
index ceab603c47..ace2d676fc 100644
--- a/src/bin/pg_ctl/pg_ctl.c
+++ b/src/bin/pg_ctl/pg_ctl.c
@@ -2159,6 +2159,7 @@ adjust_data_dir(void)
 		write_stderr(_("%s: could not determine the data directory using command \"%s\"\n"), progname, cmd);
 		exit(1);
 	}
+	free(cmd);
 	free(my_exec_path);

/* strip trailing newline and carriage return */

--
Regrads,
Japin Li.
ChengDu WenWu Information Technology Co.,Ltd.