transport: also free remote_refs in transport_disconnect()

transport_get_remote_refs() can populate the transport struct's
remote_refs. transport_disconnect() is already responsible for most of
transport's cleanup - therefore we also take care of freeing remote_refs
there.

There are 2 locations where transport_disconnect() is called before
we're done using the returned remote_refs. This patch changes those
callsites to only call transport_disconnect() after the returned refs
are no longer being used - which is necessary to safely be able to
free remote_refs during transport_disconnect().

This commit fixes the following leak which was found while running
t0000, but is expected to also fix the same pattern of leak in all
locations that use transport_get_remote_refs():

Direct leak of 165 byte(s) in 1 object(s) allocated from:
    #0 0x49a6b2 in calloc /home/abuild/rpmbuild/BUILD/llvm-11.0.0.src/build/../projects/compiler-rt/lib/asan/asan_malloc_linux.cpp:154:3
    #1 0x9a72f2 in xcalloc /home/ahunt/oss-fuzz/git/wrapper.c:140:8
    #2 0x8ce203 in alloc_ref_with_prefix /home/ahunt/oss-fuzz/git/remote.c:867:20
    #3 0x8ce1a2 in alloc_ref /home/ahunt/oss-fuzz/git/remote.c:875:9
    #4 0x72f63e in process_ref_v2 /home/ahunt/oss-fuzz/git/connect.c:426:8
    #5 0x72f21a in get_remote_refs /home/ahunt/oss-fuzz/git/connect.c:525:8
    #6 0x979ab7 in handshake /home/ahunt/oss-fuzz/git/transport.c:305:4
    #7 0x97872d in get_refs_via_connect /home/ahunt/oss-fuzz/git/transport.c:339:9
    #8 0x9774b5 in transport_get_remote_refs /home/ahunt/oss-fuzz/git/transport.c:1388:4
    #9 0x51cf80 in cmd_clone /home/ahunt/oss-fuzz/git/builtin/clone.c:1271:9
    #10 0x4cd60d in run_builtin /home/ahunt/oss-fuzz/git/git.c:453:11
    #11 0x4cb2da in handle_builtin /home/ahunt/oss-fuzz/git/git.c:704:3
    #12 0x4ccc37 in run_argv /home/ahunt/oss-fuzz/git/git.c:771:4
    #13 0x4cac29 in cmd_main /home/ahunt/oss-fuzz/git/git.c:902:19
    #14 0x69c45e in main /home/ahunt/oss-fuzz/git/common-main.c:52:11
    #15 0x7f6a459d5349 in __libc_start_main (/lib64/libc.so.6+0x24349)

Signed-off-by: Andrzej Hunt <ajrhunt@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Andrzej Hunt 2021-03-21 16:58:37 +00:00 committed by Junio C Hamano
parent 64cc539fd2
commit 68ffe095a2
3 changed files with 8 additions and 6 deletions

View File

@ -124,8 +124,6 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
int hash_algo = hash_algo_by_ptr(transport_get_hash_algo(transport));
repo_set_hash_algo(the_repository, hash_algo);
}
if (transport_disconnect(transport))
return 1;
if (!dest && !quiet)
fprintf(stderr, "From %s\n", *remote->url);
@ -151,5 +149,7 @@ int cmd_ls_remote(int argc, const char **argv, const char *prefix)
}
ref_array_clear(&ref_array);
if (transport_disconnect(transport))
return 1;
return status;
}

View File

@ -938,9 +938,6 @@ static int get_remote_ref_states(const char *name,
struct ref_states *states,
int query)
{
struct transport *transport;
const struct ref *remote_refs;
states->remote = remote_get(name);
if (!states->remote)
return error(_("No such remote: '%s'"), name);
@ -948,10 +945,12 @@ static int get_remote_ref_states(const char *name,
read_branches();
if (query) {
struct transport *transport;
const struct ref *remote_refs;
transport = transport_get(states->remote, states->remote->url_nr > 0 ?
states->remote->url[0] : NULL);
remote_refs = transport_get_remote_refs(transport, NULL);
transport_disconnect(transport);
states->queried = 1;
if (query & GET_REF_STATES)
@ -960,6 +959,7 @@ static int get_remote_ref_states(const char *name,
get_head_names(remote_refs, states);
if (query & GET_PUSH_REF_STATES)
get_push_ref_states(remote_refs, states);
transport_disconnect(transport);
} else {
for_each_ref(append_ref_to_tracked_list, states);
string_list_sort(&states->tracked);

View File

@ -1452,6 +1452,8 @@ int transport_disconnect(struct transport *transport)
int ret = 0;
if (transport->vtable->disconnect)
ret = transport->vtable->disconnect(transport);
if (transport->got_remote_refs)
free_refs((void *)transport->remote_refs);
free(transport);
return ret;
}