midx: bounds-check large offset chunk

[thirdparty/git.git] / midx.c

diff --git a/midx.c b/midx.c
index 7b1b45f381c88cbf9ec0411250145f7bf49837eb..3e768d0df079b79339b61e590d6cdd50f5bdb502 100644 (file)
--- a/midx.c
+++ b/midx.c
@@ -180,7 +180,8 @@ struct multi_pack_index *load_multi_pack_index(const char *object_dir, int local
        if (read_chunk(cf, MIDX_CHUNKID_OBJECTOFFSETS, midx_read_object_offsets, m))
                die(_("multi-pack-index required object offsets chunk missing or corrupted"));
 
-       pair_chunk_unsafe(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets);
+       pair_chunk(cf, MIDX_CHUNKID_LARGEOFFSETS, &m->chunk_large_offsets,
+                  &m->chunk_large_offsets_len);
 
        if (git_env_bool("GIT_TEST_MIDX_READ_RIDX", 1))
                pair_chunk_unsafe(cf, MIDX_CHUNKID_REVINDEX, &m->chunk_revindex);
@@ -303,8 +304,9 @@ off_t nth_midxed_offset(struct multi_pack_index *m, uint32_t pos)
                        die(_("multi-pack-index stores a 64-bit offset, but off_t is too small"));
 
                offset32 ^= MIDX_LARGE_OFFSET_NEEDED;
-               return get_be64(m->chunk_large_offsets +
-                               st_mult(sizeof(uint64_t), offset32));
+               if (offset32 >= m->chunk_large_offsets_len / sizeof(uint64_t))
+                       die(_("multi-pack-index large offset out of bounds"));
+               return get_be64(m->chunk_large_offsets + sizeof(uint64_t) * offset32);
        }
 
        return offset32;