diff mbox series

[4/6] init: make a copy of $GIT_DIR string

Message ID 20190111221631.GD10188@sigill.intra.peff.net (mailing list archive)
State New, archived
Headers show
Series getenv() timing fixes | expand

Commit Message

Jeff King Jan. 11, 2019, 10:16 p.m. UTC 
We pass the result of getenv("GIT_DIR") to init_db() and assume that the
string remains valid. But that's not guaranteed across calls to setenv()
or even getenv(), although it often works in practice. Let's make a copy
of the string so that we follow the rules.

Note that we need to mark it with UNLEAK(), since the value persists
until the end of program (but we have no opportunity to free it).

This patch also handles $GIT_WORK_TREE the same way. It actually doesn't
have as long a lifetime and is probably fine, but it's simpler to just
treat the two side-by-side variables the same.

Signed-off-by: Jeff King <peff@peff.net>
---
 builtin/init-db.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

Comments

Junio C Hamano Jan. 12, 2019, 3:08 a.m. UTC | #1 
Jeff King <peff@peff.net> writes:

> We pass the result of getenv("GIT_DIR") to init_db() and assume that the
> string remains valid. But that's not guaranteed across calls to setenv()
> or even getenv(), although it often works in practice. Let's make a copy
> of the string so that we follow the rules.
>
> Note that we need to mark it with UNLEAK(), since the value persists
> until the end of program (but we have no opportunity to free it).

Makes sense.  Thanks.
diff mbox series

Patch

diff --git a/builtin/init-db.c b/builtin/init-db.c
index 41faffd28d..93eff7618c 100644
--- a/builtin/init-db.c
+++ b/builtin/init-db.c
@@ -542,8 +542,8 @@  int cmd_init_db(int argc, const char **argv, const char *prefix)
 	 * GIT_WORK_TREE makes sense only in conjunction with GIT_DIR
 	 * without --bare.  Catch the error early.
 	 */
-	git_dir = getenv(GIT_DIR_ENVIRONMENT);
-	work_tree = getenv(GIT_WORK_TREE_ENVIRONMENT);
+	git_dir = xstrdup_or_null(getenv(GIT_DIR_ENVIRONMENT));
+	work_tree = xstrdup_or_null(getenv(GIT_WORK_TREE_ENVIRONMENT));
 	if ((!git_dir || is_bare_repository_cfg == 1) && work_tree)
 		die(_("%s (or --work-tree=<directory>) not allowed without "
 			  "specifying %s (or --git-dir=<directory>)"),
@@ -582,6 +582,8 @@  int cmd_init_db(int argc, const char **argv, const char *prefix)
 	}
 
 	UNLEAK(real_git_dir);
+	UNLEAK(git_dir);
+	UNLEAK(work_tree);
 
 	flags |= INIT_DB_EXIST_OK;
 	return init_db(git_dir, real_git_dir, template_dir, flags);