@matheusbsbs / matheus-bagliano / commits / af92a645d3

pack-objects: do not truncate result in-pack object size on 32-bit systems

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>

Nguyễn Thái Ngọc Duy committed Jul 13, 2016 at 17:44 UTC af92a645d30b9ac775cdfe5dd56ea1d66fb6e492
1 file changed +8 -7
builtin/pack-objects.c
+8 -7
@@ -341,8 +341,8 @@ static unsigned long write_no_reuse_object(struct sha1file *f, struct object_ent
341 }
342
343 /* Return 0 if we will bust the pack-size limit */
344 -static unsigned long write_reuse_object(struct sha1file *f, struct object_entry *entry,
345 - unsigned long limit, int usable_delta)
344 +static off_t write_reuse_object(struct sha1file *f, struct object_entry *entry,
345 + unsigned long limit, int usable_delta)
346 {
347 struct packed_git *p = entry->in_pack;
348 struct pack_window *w_curs = NULL;
@@ -415,11 +415,12 @@ static unsigned long write_reuse_object(struct sha1file *f, struct object_entry
415 }
416
417 /* Return 0 if we will bust the pack-size limit */
418 -static unsigned long write_object(struct sha1file *f,
419 - struct object_entry *entry,
420 - off_t write_offset)
418 +static off_t write_object(struct sha1file *f,
419 + struct object_entry *entry,
420 + off_t write_offset)
421 {
422 - unsigned long limit, len;
422 + unsigned long limit;
423 + off_t len;
424 int usable_delta, to_reuse;
425
426 if (!pack_to_stdout)
@@ -491,7 +492,7 @@ static enum write_one_status write_one(struct sha1file *f,
492 struct object_entry *e,
493 off_t *offset)
494 {
494 - unsigned long size;
495 + off_t size;
496 int recursing;
497
498 /*