@matheusbsbs / matheus-bagliano / commits / 087740d65a

scalar: free result of `remote_default_branch()`

We don't free the result of `remote_default_branch()`, leading to a memory leak. This leak is exposed by t9211, but only when run with Meson with the `-Db_sanitize=leak` option: Direct leak of 5 byte(s) in 1 object(s) allocated from: #0 0x5555555cfb93 in malloc (scalar+0x7bb93) #1 0x5555556b05c2 in do_xmalloc ../wrapper.c:55:8 #2 0x5555556b06c4 in do_xmallocz ../wrapper.c:89:8 #3 0x5555556b0656 in xmallocz ../wrapper.c:97:9 #4 0x5555556b0728 in xmemdupz ../wrapper.c:113:16 #5 0x5555556b07a7 in xstrndup ../wrapper.c:119:9 #6 0x5555555d3a4b in remote_default_branch ../scalar.c:338:14 #7 0x5555555d20e6 in cmd_clone ../scalar.c:493:28 #8 0x5555555d196b in cmd_main ../scalar.c:992:14 #9 0x5555557c4059 in main ../common-main.c:64:11 #10 0x7ffff7a2a1fb in __libc_start_call_main (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a1fb) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0) #11 0x7ffff7a2a2b8 in __libc_start_main@GLIBC_2.2.5 (/nix/store/h7zcxabfxa7v5xdna45y2hplj31ncf8a-glibc-2.40-36/lib/libc.so.6+0x2a2b8) (BuildId: 0a855678aa0cb573cecbb2bcc73ab8239ec472d0) #12 0x555555592054 in _start (scalar+0x3e054) DEDUP_TOKEN: __interceptor_malloc--do_xmalloc--do_xmallocz--xmallocz--xmemdupz--xstrndup--remote_default_branch--cmd_clone--cmd_main--main--__libc_start_call_main--__libc_start_main@GLIBC_2.2.5--_start SUMMARY: LeakSanitizer: 5 byte(s) leaked in 1 allocation(s). As the `branch` variable may contain a string constant obtained from parsing command line arguments we cannot free the leaking variable directly. Instead, introduce a new `branch_to_free` variable that only ever gets assigned the allocated string and free that one to plug the leak. It is unclear why the leak isn't flagged when running the test via our Makefile. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Patrick Steinhardt committed Jan 30, 2025 at 07:17 UTC 087740d65a5d28756ecbe56fc3b10328b52e8d33

1 file changed +3 -1

scalar.c

+3 -1

@@ -408,6 +408,7 @@ void load_builtin_commands(const char *prefix, struct cmdnames *cmds)

408 static int cmd_clone(int argc, const char **argv)

409 {

410 const char *branch = NULL;

411 + char *branch_to_free = NULL;

412 int full_clone = 0, single_branch = 0, show_progress = isatty(2);

413 int src = 1;

414 struct option clone_options[] = {

@@ -487,7 +488,7 @@ static int cmd_clone(int argc, const char **argv)

488 /* common-main already logs `argv` */

489 trace2_def_repo(the_repository);

490

490 - if (!branch && !(branch = remote_default_branch(url))) {

491 + if (!branch && !(branch = branch_to_free = remote_default_branch(url))) {

492 res = error(_("failed to get default branch for '%s'"), url);

493 goto cleanup;

494 }

@@ -542,6 +543,7 @@ static int cmd_clone(int argc, const char **argv)

543 res = register_dir();

544

545 cleanup:

546 + free(branch_to_free);

547 free(enlistment);

548 free(dir);

549 strbuf_release(&buf);