In a similar spirit as previous commits, ensure that we don't overflow
in a few spots within `fill_commit_graph_info()`:
- First, when computing an offset into the commit data chunk, which
can occur when the `lex_index` of the item we're looking up exceeds
2^32-1/GRAPH_DATA_WIDTH.
- A similar issue when computing the generation date offset for
commits with `lex_index` greater than 2^32-1/4. Note that in
practice this will never overflow, since the left-hand operand is
from calling `sizeof(...)` and is thus already a `size_t`. But wrap
that in an `st_mult()` to make it clear that we intend to perform
this computation using 64-bit operands.
- Finally, a nearly identical issue as above when computing an offset
into the `generation_data_overflow` chunk.
Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx>
---
commit-graph.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/commit-graph.c b/commit-graph.c
index 1b70bdb07e..ceaeb8b785 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -789,7 +789,7 @@ static void fill_commit_graph_info(struct commit *item, struct commit_graph *g,
die(_("invalid commit position. commit-graph is likely corrupt"));
lex_index = pos - g->num_commits_in_base;
- commit_data = g->chunk_commit_data + GRAPH_DATA_WIDTH * lex_index;
+ commit_data = g->chunk_commit_data + st_mult(GRAPH_DATA_WIDTH, lex_index);
graph_data = commit_graph_data_at(item);
graph_data->graph_pos = pos;
@@ -799,14 +799,14 @@ static void fill_commit_graph_info(struct commit *item, struct commit_graph *g,
item->date = (timestamp_t)((date_high << 32) | date_low);
if (g->read_generation_data) {
- offset = (timestamp_t)get_be32(g->chunk_generation_data + sizeof(uint32_t) * lex_index);
+ offset = (timestamp_t)get_be32(g->chunk_generation_data + st_mult(sizeof(uint32_t), lex_index));
if (offset & CORRECTED_COMMIT_DATE_OFFSET_OVERFLOW) {
if (!g->chunk_generation_data_overflow)
die(_("commit-graph requires overflow generation data but has none"));
offset_pos = offset ^ CORRECTED_COMMIT_DATE_OFFSET_OVERFLOW;
- graph_data->generation = item->date + get_be64(g->chunk_generation_data_overflow + 8 * offset_pos);
+ graph_data->generation = item->date + get_be64(g->chunk_generation_data_overflow + st_mult(8, offset_pos));
} else
graph_data->generation = item->date + offset;
} else
--
2.41.0.347.g7b976b8871f
