commit-graph: verify corrupt OID fanout and lookup
In the commit-graph file, the OID fanout chunk provides an index into the OID lookup. The 'verify' subcommand should find incorrect values in the fanout. Similarly, the 'verify' subcommand should find out-of-order values in the OID lookup. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Derrick Stolee committed
Jun 27, 2018 at 09:24 UTC
9bda84678950c95e4d81cad60e5210c001fbe119
2 files changed
+58
commit-graph.c
+36
@@ -843,6 +843,9 @@ static void graph_report(const char *fmt, ...)
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int verify_commit_graph(struct repository *r, struct commit_graph *g)
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{
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+ uint32_t i, cur_fanout_pos = 0;
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+ struct object_id prev_oid, cur_oid;
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+
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if (!g) {
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graph_report("no commit-graph file loaded");
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return 1;
@@ -857,5 +860,38 @@ int verify_commit_graph(struct repository *r, struct commit_graph *g)
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if (!g->chunk_commit_data)
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graph_report("commit-graph is missing the Commit Data chunk");
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+ if (verify_commit_graph_error)
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+ return verify_commit_graph_error;
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+
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+ for (i = 0; i < g->num_commits; i++) {
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+ hashcpy(cur_oid.hash, g->chunk_oid_lookup + g->hash_len * i);
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+
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+ if (i && oidcmp(&prev_oid, &cur_oid) >= 0)
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+ graph_report("commit-graph has incorrect OID order: %s then %s",
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+ oid_to_hex(&prev_oid),
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+ oid_to_hex(&cur_oid));
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+
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+ oidcpy(&prev_oid, &cur_oid);
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+
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+ while (cur_oid.hash[0] > cur_fanout_pos) {
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+ uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
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+
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+ if (i != fanout_value)
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+ graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
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+ cur_fanout_pos, fanout_value, i);
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+ cur_fanout_pos++;
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+ }
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+ }
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+
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+ while (cur_fanout_pos < 256) {
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+ uint32_t fanout_value = get_be32(g->chunk_oid_fanout + cur_fanout_pos);
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+
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+ if (g->num_commits != fanout_value)
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+ graph_report("commit-graph has incorrect fanout value: fanout[%d] = %u != %u",
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+ cur_fanout_pos, fanout_value, i);
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+
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+ cur_fanout_pos++;
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+ }
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+
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return verify_commit_graph_error;
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}
t/t5318-commit-graph.sh
+22
@@ -247,6 +247,7 @@ test_expect_success 'git commit-graph verify' '
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git commit-graph verify >output
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'
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+HASH_LEN=20
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GRAPH_BYTE_VERSION=4
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GRAPH_BYTE_HASH=5
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GRAPH_BYTE_CHUNK_COUNT=6
@@ -258,6 +259,12 @@ GRAPH_BYTE_OID_LOOKUP_ID=$(($GRAPH_CHUNK_LOOKUP_OFFSET + \
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1 * $GRAPH_CHUNK_LOOKUP_WIDTH))
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GRAPH_BYTE_COMMIT_DATA_ID=$(($GRAPH_CHUNK_LOOKUP_OFFSET + \
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2 * $GRAPH_CHUNK_LOOKUP_WIDTH))
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+GRAPH_FANOUT_OFFSET=$(($GRAPH_CHUNK_LOOKUP_OFFSET + \
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+ $GRAPH_CHUNK_LOOKUP_WIDTH * $GRAPH_CHUNK_LOOKUP_ROWS))
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+GRAPH_BYTE_FANOUT1=$(($GRAPH_FANOUT_OFFSET + 4 * 4))
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+GRAPH_BYTE_FANOUT2=$(($GRAPH_FANOUT_OFFSET + 4 * 255))
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+GRAPH_OID_LOOKUP_OFFSET=$(($GRAPH_FANOUT_OFFSET + 4 * 256))
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+GRAPH_BYTE_OID_LOOKUP_ORDER=$(($GRAPH_OID_LOOKUP_OFFSET + $HASH_LEN * 8))
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# usage: corrupt_graph_and_verify <position> <data> <string>
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# Manipulates the commit-graph file at the position
@@ -312,4 +319,19 @@ test_expect_success 'detect missing commit data chunk' '
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"missing the Commit Data chunk"
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'
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+test_expect_success 'detect incorrect fanout' '
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+ corrupt_graph_and_verify $GRAPH_BYTE_FANOUT1 "\01" \
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+ "fanout value"
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+'
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+
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+test_expect_success 'detect incorrect fanout final value' '
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+ corrupt_graph_and_verify $GRAPH_BYTE_FANOUT2 "\01" \
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+ "fanout value"
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+'
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+
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+test_expect_success 'detect incorrect OID order' '
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+ corrupt_graph_and_verify $GRAPH_BYTE_OID_LOOKUP_ORDER "\01" \
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+ "incorrect OID order"
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+'
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+
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test_done