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negotiator/default: avoid stack overflow

mark_common() in negotiator/default.c may overflow the stack due to
recursive function calls. Avoid this by instead recursing using a
heap-allocated data structure.

This is the same case as 4654134976 (negotiator/skipping: avoid
stack overflow, 2022-10-25)

Reported-by: Xin Xing <xingxin.xx@bytedance.com>
Signed-off-by: Han Xin <hanxin.hx@bytedance.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Han Xin 2023-04-26 21:15:03 +08:00 committed by Junio C Hamano
parent 2807bd2c10
commit 8e21ff5edb

View File

@ -55,30 +55,49 @@ static int clear_marks(const char *refname, const struct object_id *oid,
static void mark_common(struct negotiation_state *ns, struct commit *commit,
int ancestors_only, int dont_parse)
{
if (commit != NULL && !(commit->object.flags & COMMON)) {
struct object *o = (struct object *)commit;
struct prio_queue queue = { NULL };
if (!ancestors_only)
o->flags |= COMMON;
if (!commit || (commit->object.flags & COMMON))
return;
prio_queue_put(&queue, commit);
if (!ancestors_only) {
commit->object.flags |= COMMON;
if ((commit->object.flags & SEEN) && !(commit->object.flags & POPPED))
ns->non_common_revs--;
}
while ((commit = prio_queue_get(&queue))) {
struct object *o = (struct object *)commit;
if (!(o->flags & SEEN))
rev_list_push(ns, commit, SEEN);
else {
struct commit_list *parents;
if (!ancestors_only && !(o->flags & POPPED))
ns->non_common_revs--;
if (!o->parsed && !dont_parse)
if (repo_parse_commit(the_repository, commit))
return;
continue;
for (parents = commit->parents;
parents;
parents = parents->next)
mark_common(ns, parents->item, 0,
dont_parse);
parents = parents->next) {
struct commit *p = parents->item;
if (p->object.flags & COMMON)
continue;
p->object.flags |= COMMON;
if ((p->object.flags & SEEN) && !(p->object.flags & POPPED))
ns->non_common_revs--;
prio_queue_put(&queue, parents->item);
}
}
}
clear_prio_queue(&queue);
}
/*