commit-graph.c: prevent overflow in fill_commit_in_graph()

In a similar spirit as previous commits, ensure that we don't overflow
when the lex_index of the commit we are trying to fill out exceeds
2^32-1/(g->hash_len+16).

The other hunk touched in this patch is not susceptible to overflow,
since an explicit cast is made to a 64-bit unsigned value. For clarity
and consistency with the rest of the commits in this series, avoid a
tricky to reason about cast, and use `st_mult()` directly.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Taylor Blau
2023-07-12 19:38:05 -04:00
committed by Junio C Hamano
parent 2740ed1c76
commit 50a71c2942

View File

@ -838,7 +838,7 @@ static int fill_commit_in_graph(struct repository *r,
fill_commit_graph_info(item, g, pos);
lex_index = pos - g->num_commits_in_base;
commit_data = g->chunk_commit_data + (g->hash_len + 16) * lex_index;
commit_data = g->chunk_commit_data + st_mult(g->hash_len + 16, lex_index);
item->object.parsed = 1;
@ -860,7 +860,7 @@ static int fill_commit_in_graph(struct repository *r,
}
parent_data_ptr = (uint32_t*)(g->chunk_extra_edges +
4 * (uint64_t)(edge_value & GRAPH_EDGE_LAST_MASK));
st_mult(4, edge_value & GRAPH_EDGE_LAST_MASK));
do {
edge_value = get_be32(parent_data_ptr);
pptr = insert_parent_or_die(r, g,