From: Johannes Schindelin via GitGitGadget Date: Tue, 28 Apr 2026 16:26:15 GMT Subject: [PATCH 1/6] index-pack, unpack-objects: use size_t for object size Message-ID: In-Reply-To: From: Johannes Schindelin When unpacking objects from a packfile, the object size is decoded from a variable-length encoding. On platforms where unsigned long is 32-bit (such as Windows, even in 64-bit builds), the shift operation overflows when decoding sizes larger than 4GB. The result is a truncated size value, causing the unpacked object to be corrupted or rejected. Fix this by changing the size variable to size_t, which is 64-bit on 64-bit platforms, and ensuring the shift arithmetic occurs in 64-bit space. This was originally authored by LordKiRon , who preferred not to reveal their real name and therefore agreed that I take over authorship. Signed-off-by: Johannes Schindelin --- builtin/index-pack.c | 9 +++++---- builtin/unpack-objects.c | 5 +++-- 2 files changed, 8 insertions(+), 6 deletions(-) diff --git a/builtin/index-pack.c b/builtin/index-pack.c index ca7784dc2c..cc660582e9 100644 --- a/builtin/index-pack.c +++ b/builtin/index-pack.c @@ -37,7 +37,7 @@ static const char index_pack_usage[] = struct object_entry { struct pack_idx_entry idx; - unsigned long size; + size_t size; unsigned char hdr_size; signed char type; signed char real_type; @@ -469,7 +469,7 @@ static int is_delta_type(enum object_type type) return (type == OBJ_REF_DELTA || type == OBJ_OFS_DELTA); } -static void *unpack_entry_data(off_t offset, unsigned long size, +static void *unpack_entry_data(off_t offset, size_t size, enum object_type type, struct object_id *oid) { static char fixed_buf[8192]; @@ -524,7 +524,8 @@ static void *unpack_raw_entry(struct object_entry *obj, struct object_id *oid) { unsigned char *p; - unsigned long size, c; + size_t size; + unsigned long c; off_t base_offset; unsigned shift; void *data; @@ -542,7 +543,7 @@ static void *unpack_raw_entry(struct object_entry *obj, p = fill(1); c = *p; use(1); - size += (c & 0x7f) << shift; + size += ((size_t)c & 0x7f) << shift; shift += 7; } obj->size = size; diff --git a/builtin/unpack-objects.c b/builtin/unpack-objects.c index e01cf6e360..59a36c2481 100644 --- a/builtin/unpack-objects.c +++ b/builtin/unpack-objects.c @@ -533,7 +533,8 @@ static void unpack_one(unsigned nr) { unsigned shift; unsigned char *pack; - unsigned long size, c; + size_t size; + unsigned long c; enum object_type type; obj_list[nr].offset = consumed_bytes; @@ -548,7 +549,7 @@ static void unpack_one(unsigned nr) pack = fill(1); c = *pack; use(1); - size += (c & 0x7f) << shift; + size += ((size_t)c & 0x7f) << shift; shift += 7; } -- gitgitgadget