diff options
| author | Taylor Blau <me@ttaylorr.com> | 2023-07-13 20:54:54 -0400 |
|---|---|---|
| committer | Junio C Hamano <gitster@pobox.com> | 2023-07-14 09:31:34 -0700 |
| commit | 42be681b33ef73be056fb99e3c63c6e9b9c2e7ef (patch) | |
| tree | dcdb2e0ebeebbd83ba1e560792edeb69225a6888 | |
| parent | de41d03e1c7ab73174716c99b8eaf7ff5884d6bb (diff) | |
| download | git-42be681b33ef73be056fb99e3c63c6e9b9c2e7ef.tar.xz | |
packfile.c: prevent overflow in `load_idx()`
Prevent an overflow when locating a pack's CRC offset when the number
of packed items is greater than 2^32-1/hashsz by guarding the
computation with an `st_mult()`.
Note that to avoid truncating the result, the `crc_offset` member must
itself become a `size_t`. The only usage of this variable (besides the
assignment in `load_idx()`) is in `read_v2_anomalous_offsets()` in the
index-pack code. There we use the `crc_offset` as a pointer offset, so
we are already equipped to handle the type change.
Helped-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
| -rw-r--r-- | object-store.h | 2 | ||||
| -rw-r--r-- | packfile.c | 2 |
2 files changed, 2 insertions, 2 deletions
diff --git a/object-store.h b/object-store.h index 12415e5ea7..cfe47c9c07 100644 --- a/object-store.h +++ b/object-store.h @@ -110,7 +110,7 @@ struct packed_git { const void *index_data; size_t index_size; uint32_t num_objects; - uint32_t crc_offset; + size_t crc_offset; struct oidset bad_objects; int index_version; time_t mtime; diff --git a/packfile.c b/packfile.c index 5ee67de569..efe4a22c63 100644 --- a/packfile.c +++ b/packfile.c @@ -186,7 +186,7 @@ int load_idx(const char *path, const unsigned int hashsz, void *idx_map, */ (sizeof(off_t) <= 4)) return error("pack too large for current definition of off_t in %s", path); - p->crc_offset = 8 + 4 * 256 + nr * hashsz; + p->crc_offset = st_add(8 + 4 * 256, st_mult(nr, hashsz)); } p->index_version = version; |