From: "Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
To: git@vger.kernel.org
Cc: "Junio C Hamano" <gitster@pobox.com>,
michelbach94@gmail.com,
"Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>
Subject: [PATCH v2 6/7] pack-objects: do not truncate result in-pack object size on 32-bit systems
Date: Wed, 13 Jul 2016 17:44:03 +0200 [thread overview]
Message-ID: <20160713154404.22909-7-pclouds@gmail.com> (raw)
In-Reply-To: <20160713154404.22909-1-pclouds@gmail.com>
A typical diff will not show what's going on and you need to see full
functions. The core code is like this, at the end of of write_one()
e->idx.offset = *offset;
size = write_object(f, e, *offset);
if (!size) {
e->idx.offset = recursing;
return WRITE_ONE_BREAK;
}
written_list[nr_written++] = &e->idx;
/* make sure off_t is sufficiently large not to wrap */
if (signed_add_overflows(*offset, size))
die("pack too large for current definition of off_t");
*offset += size;
Here we can see that the in-pack object size is returned by
write_object (or indirectly by write_reuse_object). And it's used to
calculate object offsets, which end up in the pack index file,
generated at the end.
If "size" overflows (on 32-bit sytems, unsigned long is 32-bit while
off_t can be 64-bit), we got wrong offsets and produce incorrect .idx
file, which may make it look like the .pack file is corrupted.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
---
builtin/pack-objects.c | 15 ++++++++-------
1 file changed, 8 insertions(+), 7 deletions(-)
diff --git a/builtin/pack-objects.c b/builtin/pack-objects.c
index a3a98c5..ac7a3a5 100644
--- a/builtin/pack-objects.c
+++ b/builtin/pack-objects.c
@@ -341,8 +341,8 @@ static unsigned long write_no_reuse_object(struct sha1file *f, struct object_ent
}
/* Return 0 if we will bust the pack-size limit */
-static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry,
- unsigned long limit, int usable_delta)
+static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
+ unsigned long limit, int usable_delta)
{
struct packed_git *p = entry->in_pack;
struct pack_window *w_curs = NULL;
@@ -415,11 +415,12 @@ static unsigned long write_reuse_object(struct sha1file *f, struct object_entry
}
/* Return 0 if we will bust the pack-size limit */
-static unsigned long write_object(struct sha1file *f,
- struct object_entry *entry,
- off_t write_offset)
+static off_t write_object(struct sha1file *f,
+ struct object_entry *entry,
+ off_t write_offset)
{
- unsigned long limit, len;
+ unsigned long limit;
+ off_t len;
int usable_delta, to_reuse;
if (!pack_to_stdout)
@@ -491,7 +492,7 @@ static enum write_one_status write_one(struct sha1file *f,
struct object_entry *e,
off_t *offset)
{
- unsigned long size;
+ off_t size;
int recursing;
/*
--
2.9.1.564.gb2f7278
next prev parent reply other threads:[~2016-07-13 15:45 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-24 22:38 [bug] Reliably Reproducible Bad Packing of Objects Christoph Michelbach
2016-07-02 9:10 ` Duy Nguyen
2016-07-02 14:35 ` Duy Nguyen
2016-07-05 17:05 ` [PATCH 0/5] Number truncation with 4+ GB files on 32-bit systems Nguyễn Thái Ngọc Duy
2016-07-05 17:05 ` [PATCH 1/5] pack-objects: pass length to check_pack_crc() without truncation Nguyễn Thái Ngọc Duy
2016-07-12 17:16 ` Junio C Hamano
2016-07-05 17:05 ` [PATCH 2/5] sha1_file.c: use type off_t* for object_info->disk_sizep Nguyễn Thái Ngọc Duy
2016-07-12 17:20 ` Junio C Hamano
2016-07-12 19:26 ` Junio C Hamano
2016-07-05 17:05 ` [PATCH 3/5] index-pack: correct "len" type in unpack_data() Nguyễn Thái Ngọc Duy
2016-07-05 20:25 ` Johannes Sixt
2016-07-06 15:25 ` Duy Nguyen
2016-07-06 16:04 ` Junio C Hamano
2016-07-06 16:08 ` Junio C Hamano
2016-07-05 17:05 ` [PATCH 4/5] index-pack: report correct bad object offsets even if they are large Nguyễn Thái Ngọc Duy
2016-07-12 17:24 ` Junio C Hamano
2016-07-12 19:27 ` Junio C Hamano
2016-07-05 17:05 ` [PATCH 5/5] index-pack: correct "offset" type in unpack_entry_data() Nguyễn Thái Ngọc Duy
2016-07-05 18:11 ` [PATCH 0/5] Number truncation with 4+ GB files on 32-bit systems Christoph Michelbach
[not found] ` <1467756891.4798.1.camel@gmail.com>
[not found] ` <CACsJy8BDQbanGsf=3z3K-OuH0++EuqQFEB22udXJT+WZnFKSBg@mail.gmail.com>
2016-07-06 18:02 ` Christoph Michelbach
2016-07-06 18:54 ` Duy Nguyen
2016-07-10 10:41 ` Duy Nguyen
2016-07-10 10:42 ` [PATCH 6/5] pack-objects: do not truncate result in-pack object size " Nguyễn Thái Ngọc Duy
2016-07-10 10:45 ` [PATCH 7/5] fsck: use streaming interface for large blobs in pack Nguyễn Thái Ngọc Duy
2016-07-12 18:39 ` Junio C Hamano
2016-07-12 19:06 ` Junio C Hamano
2016-07-12 17:07 ` [PATCH 0/5] Number truncation with 4+ GB files on 32-bit systems Junio C Hamano
2016-07-12 18:48 ` Junio C Hamano
2016-07-12 20:38 ` Junio C Hamano
2016-07-13 6:01 ` Duy Nguyen
2016-07-13 15:43 ` [PATCH v2 0/7] " Nguyễn Thái Ngọc Duy
2016-07-13 15:43 ` [PATCH v2 1/7] pack-objects: pass length to check_pack_crc() without truncation Nguyễn Thái Ngọc Duy
2016-07-13 15:43 ` [PATCH v2 2/7] sha1_file.c: use type off_t* for object_info->disk_sizep Nguyễn Thái Ngọc Duy
2016-07-13 15:44 ` [PATCH v2 3/7] index-pack: correct "len" type in unpack_data() Nguyễn Thái Ngọc Duy
2016-07-13 15:44 ` [PATCH v2 4/7] index-pack: report correct bad object offsets even if they are large Nguyễn Thái Ngọc Duy
2016-07-13 15:44 ` [PATCH v2 5/7] index-pack: correct "offset" type in unpack_entry_data() Nguyễn Thái Ngọc Duy
2016-07-13 15:44 ` Nguyễn Thái Ngọc Duy [this message]
2016-07-13 15:44 ` [PATCH v2 7/7] fsck: use streaming interface for large blobs in pack Nguyễn Thái Ngọc Duy
2016-07-13 16:16 ` [PATCH v2 0/7] Number truncation with 4+ GB files on 32-bit systems Junio C Hamano
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