commit-graph: check order while reading fanout chunk

We read the fanout chunk, storing a pointer to it, but only confirm that
the entries are monotonic in a final "lite" verification step. Let's
move that into the actual OIDF chunk callback, so that we can report
problems immediately (for all the reasons given in the previous
"commit-graph: abort as soon as we see a bogus chunk" commit).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Jeff King 2023-11-09 02:25:07 -05:00 committed by Junio C Hamano
parent d3b6f6c631
commit 06fb135f8e
2 changed files with 15 additions and 13 deletions

View file

@ -277,8 +277,6 @@ struct commit_graph *load_commit_graph_one_fd_st(struct repository *r,
static int verify_commit_graph_lite(struct commit_graph *g)
{
int i;
/*
* Basic validation shared between parse_commit_graph()
* which'll be called every time the graph is used, and the
@ -291,6 +289,20 @@ static int verify_commit_graph_lite(struct commit_graph *g)
* over g->num_commits, or runs a checksum on the commit-graph
* itself.
*/
return 0;
}
static int graph_read_oid_fanout(const unsigned char *chunk_start,
size_t chunk_size, void *data)
{
struct commit_graph *g = data;
int i;
if (chunk_size != 256 * sizeof(uint32_t))
return error("commit-graph oid fanout chunk is wrong size");
g->chunk_oid_fanout = (const uint32_t *)chunk_start;
g->num_commits = ntohl(g->chunk_oid_fanout[255]);
for (i = 0; i < 255; i++) {
uint32_t oid_fanout1 = ntohl(g->chunk_oid_fanout[i]);
uint32_t oid_fanout2 = ntohl(g->chunk_oid_fanout[i + 1]);
@ -304,17 +316,6 @@ static int verify_commit_graph_lite(struct commit_graph *g)
return 0;
}
static int graph_read_oid_fanout(const unsigned char *chunk_start,
size_t chunk_size, void *data)
{
struct commit_graph *g = data;
if (chunk_size != 256 * sizeof(uint32_t))
return error("commit-graph oid fanout chunk is wrong size");
g->chunk_oid_fanout = (const uint32_t *)chunk_start;
g->num_commits = ntohl(g->chunk_oid_fanout[255]);
return 0;
}
static int graph_read_oid_lookup(const unsigned char *chunk_start,
size_t chunk_size, void *data)
{

View file

@ -867,6 +867,7 @@ test_expect_success 'reader notices out-of-bounds fanout' '
check_corrupt_chunk OIDF 0 $(printf "%02x000000" $(test_seq 0 254)) &&
cat >expect.err <<-\EOF &&
error: commit-graph fanout values out of order
error: commit-graph required OID fanout chunk missing or corrupted
EOF
test_cmp expect.err err
'