[PATCH 2/2] fix "bundle --stdin" segfault
- From
Jonathan Nieder <jrnieder@gmail.com>
- Date
- Apr 19, 2010, 08:03 UTC
- Message-ID
- <20100419080340.GB23609@progeny.tock>
- In-Reply-To
- <20100419071449.GA23166@progeny.tock>
When passed an empty list, objects_array_remove_duplicates() corrupts it by changing the number of entries from 0 to 1.
The problem lies in the condition of its main loop:
for (ref = 0; ref < array->nr - 1; ref++) {The loop body manipulates the supplied object array. In the case of an empty array, it should not be doing anything at all. But array->nr is an unsigned quantity, so the code enters the loop, in particular increasing array->nr. Fix this by comparing (ref + 1 < array->nr) instead.
This bug can be triggered by git bundle --stdin:
$ echo HEAD | git bundle create some.bundle --stdin’ Segmentation fault (core dumped)
The list of commits to bundle appears to be empty because of another bug: by the time the revision-walking machinery gets to look at it, standard input has already been consumed by rev-list, so ...remove_duplicates() gets an empty list of revisions.
After this patch, git bundle --stdin still does not work; it just doesn’t segfault any more.
Reported-by: Joey Hess <joey@kitenet.net> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> --- object.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/object.c b/object.c index 3ca92c4..277b3dd 100644 --- a/object.c +++ b/object.c @@ -252,10 +252,10 @@ void add_object_array_with_mode(struct object *obj, const char *name, struct obj void object_array_remove_duplicates(struct object_array *array) { - int ref, src, dst; + unsigned int ref, src, dst; struct object_array_entry *objects = array->objects; - for (ref = 0; ref < array->nr - 1; ref++) { + for (ref = 0; ref + 1 < array->nr; ref++) { for (src = ref + 1, dst = src; src < array->nr; src++) {
-- 1.7.1.rc1