In some instances, match_refs() sets the peer_ref field of refs in the
dst list such that it points to a ref in the src list. This prevents
callers from freeing both the src and dst lists, as doing so would cause
a double-free since free_refs() frees the peer_ref.
As well, the following configuration causes two refs in the dst list to
have the same peer_ref, which can also lead to a double-free:
push = refs/heads/master:refs/heads/backup
push = refs/heads/master:refs/heads/master
Existing callers of match_heads() call it only once and then terminate,
w/o ever bothering to free the src or dst lists, so this is not
currently a problem.
This patch modifies match_refs() to first copy any refs it plucks from
the src list before assigning them as a peer_ref, thus future-proofing
the function against callers who might wish to free the src and/or dst
lists.
Signed-off-by: Jay Soffian <jaysoffian@xxxxxxxxx>
---
remote.c | 7 +++++--
1 files changed, 5 insertions(+), 2 deletions(-)
diff --git a/remote.c b/remote.c
index 6385a22..64879ce 100644
--- a/remote.c
+++ b/remote.c
@@ -927,6 +927,7 @@ static int match_explicit(struct ref *src, struct ref *dst,
struct refspec *rs)
{
struct ref *matched_src, *matched_dst;
+ int copy_src;
const char *dst_value = rs->dst;
char *dst_guess;
@@ -937,6 +938,7 @@ static int match_explicit(struct ref *src, struct ref *dst,
matched_src = matched_dst = NULL;
switch (count_refspec_match(rs->src, src, &matched_src)) {
case 1:
+ copy_src = 1;
break;
case 0:
/* The source could be in the get_sha1() format
@@ -946,6 +948,7 @@ static int match_explicit(struct ref *src, struct ref *dst,
matched_src = try_explicit_object_name(rs->src);
if (!matched_src)
return error("src refspec %s does not match any.", rs->src);
+ copy_src = 0;
break;
default:
return error("src refspec %s matches more than one.", rs->src);
@@ -991,7 +994,7 @@ static int match_explicit(struct ref *src, struct ref *dst,
return error("dst ref %s receives from more than one src.",
matched_dst->name);
else {
- matched_dst->peer_ref = matched_src;
+ matched_dst->peer_ref = copy_src ? copy_ref(matched_src) : matched_src;
matched_dst->force = rs->force;
}
return 0;
@@ -1099,7 +1102,7 @@ int match_refs(struct ref *src, struct ref *dst, struct ref ***dst_tail,
dst_peer = make_linked_ref(dst_name, dst_tail);
hashcpy(dst_peer->new_sha1, src->new_sha1);
}
- dst_peer->peer_ref = src;
+ dst_peer->peer_ref = copy_ref(src);
dst_peer->force = pat->force;
free_name:
free(dst_name);
--
1.6.2.rc1.291.g83eb
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