Am 30.05.2017 um 19:30 schrieb Brandon Williams:
> @@ -392,7 +392,7 @@ static int add(int argc, const char **argv, const char *prefix)
> const char *object_ref;
> struct notes_tree *t;
> unsigned char object[20], new_note[20];
> - const unsigned char *note;
> + const struct object_id *note;
> struct note_data d = { 0, 0, NULL, STRBUF_INIT };
> struct option options[] = {
> { OPTION_CALLBACK, 'm', "message", &d, N_("message"),
In between here, note can be set to NULL...
> @@ -453,7 +453,7 @@ static int add(int argc, const char **argv, const char *prefix)
> sha1_to_hex(object));
> }
>
> - prepare_note_data(object, &d, note);
> + prepare_note_data(object, &d, note->hash);
... which we then dereference here.
> @@ -598,13 +598,13 @@ static int append_edit(int argc, const char **argv, const char *prefix)
> t = init_notes_check(argv[0], NOTES_INIT_WRITABLE);
> note = get_note(t, object);
>
> - prepare_note_data(object, &d, edit ? note : NULL);
> + prepare_note_data(object, &d, edit && note ? note->hash : NULL);
Here a NULL check was added; we need a similar one above as well.
-- >8 --
Subject: [PATCH] notes: don't access hash of NULL object_id pointer
Check if note is NULL, as we already do for different purposes a few
lines above, and pass a NULL pointer to prepare_note_data() in that
case instead of trying to access the hash member.
Found with Clang's UBSan.
Signed-off-by: Rene Scharfe <l.s.r@xxxxxx>
---
The third parameter of prepare_note_data() could easily be turned into
an object_id pointer (and it should), but this patch is meant to be a
minimal fix.
builtin/notes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/builtin/notes.c b/builtin/notes.c
index 77573cf1ea..4303848e04 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -456,7 +456,7 @@ static int add(int argc, const char **argv, const char *prefix)
oid_to_hex(&object));
}
- prepare_note_data(&object, &d, note->hash);
+ prepare_note_data(&object, &d, note ? note->hash : NULL);
if (d.buf.len || allow_empty) {
write_note_data(&d, new_note.hash);
if (add_note(t, &object, &new_note, combine_notes_overwrite))
--
2.13.3
