git/list[1] front-page[2] threads[3] people[4] search[5] about
 

[PATCH 18/20] commit-graph.c: prevent overflow in `merge_commit_graph()`

From
Taylor Blau <me@ttaylorr.com>
Date
Jul 12, 2023, 23:38 UTC
Message-ID
<094aca51c2c23fe74016c60d5ba31c325da038d2.1689205042.git.me@ttaylorr.com>
In-Reply-To
<cover.1689205042.git.me@ttaylorr.com>

When merging two commit graphs, ensure that we don't attempt to merge two graphs which, when combined, have more total commits than the 32-bit unsigned maximum.

Signed-off-by: Taylor Blau <me@ttaylorr.com>
---
 commit-graph.c | 5 +++++
 1 file changed, 5 insertions(+)
diff --git a/commit-graph.c b/commit-graph.c
index 8010e0763e..c679d1d633 100644
--- a/commit-graph.c
+++ b/commit-graph.c
@@ -2178,6 +2178,11 @@ static void merge_commit_graph(struct write_commit_graph_context *ctx,
 	uint32_t i;
 	uint32_t offset = g->num_commits_in_base;
 
+	if (unsigned_add_overflows(ctx->commits.nr, g->num_commits))
+		die(_("cannot merge graph %s, too many commits: %"PRIuMAX),
+		    oid_to_hex(&g->oid),
+		    (uintmax_t)st_add(ctx->commits.nr, g->num_commits));
+
 	ALLOC_GROW(ctx->commits.list, ctx->commits.nr + g->num_commits, ctx->commits.alloc);
 
 	for (i = 0; i < g->num_commits; i++) {
-- 
2.41.0.347.g7b976b8871f
Previous: Taylor BlauNext: Taylor Blau
Message 25 of 28 in “guard object lookups against 32-bit overflow”
  1. 00/20 guard object lookups against 32-bit overflowTaylor Blau, Jul 12, 2023
  2. 01/20 packfile.c: prevent overflow in `nth_packed_object_id()`Taylor Blau, Jul 12, 2023
  3. 02/20 packfile.c: prevent overflow in `load_idx()`Taylor Blau, Jul 12, 2023
  4. Phillip WoodJul 13, 2023
  5. Taylor BlauJul 13, 2023
  6. Taylor BlauJul 14, 2023
  7. Phillip WoodJul 14, 2023
  8. Junio C HamanoJul 14, 2023
  9. Phillip WoodJul 14, 2023
  10. Junio C HamanoJul 13, 2023
  11. 03/20 packfile.c: use checked arithmetic in `nth_packed_object_offset()`Taylor Blau, Jul 12, 2023
  12. 04/20 midx.c: use `size_t`'s for fanout nr and allocTaylor Blau, Jul 12, 2023
  13. 05/20 midx.c: prevent overflow in `nth_midxed_object_oid()`Taylor Blau, Jul 12, 2023
  14. 06/20 midx.c: prevent overflow in `nth_midxed_offset()`Taylor Blau, Jul 12, 2023
  15. 08/20 midx.c: prevent overflow in `write_midx_internal()`Taylor Blau, Jul 12, 2023
  16. 09/20 midx.c: prevent overflow in `fill_included_packs_batch()`Taylor Blau, Jul 12, 2023
  17. 10/20 pack-bitmap.c: ensure that eindex lookups don't overflowTaylor Blau, Jul 12, 2023
  18. 11/20 commit-graph.c: prevent overflow in `write_commit_graph_file()`Taylor Blau, Jul 12, 2023
  19. 12/20 commit-graph.c: prevent overflow in add_graph_to_chain()Taylor Blau, Jul 12, 2023
  20. 13/20 commit-graph.c: prevent overflow in `load_oid_from_graph()`Taylor Blau, Jul 12, 2023
  21. 14/20 commit-graph.c: prevent overflow in `fill_commit_graph_info()`Taylor Blau, Jul 12, 2023
  22. 15/20 commit-graph.c: prevent overflow in `fill_commit_in_graph()`Taylor Blau, Jul 12, 2023
  23. 16/20 commit-graph.c: prevent overflow in `load_tree_for_commit()`Taylor Blau, Jul 12, 2023
  24. 17/20 commit-graph.c: prevent overflow in `split_graph_merge_strategy()`Taylor Blau, Jul 12, 2023
  25. 18/20 commit-graph.c: prevent overflow in `merge_commit_graph()`Taylor Blau, Jul 12, 2023
  26. 19/20 commit-graph.c: prevent overflow in `write_commit_graph()`Taylor Blau, Jul 12, 2023
  27. 20/20 commit-graph.c: prevent overflow in `verify_commit_graph()`Taylor Blau, Jul 12, 2023
  28. 07/20 midx.c: store `nr`, `alloc` variables as `size_t`'sTaylor Blau, Jul 12, 2023

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.