| #!/bin/sh |
| |
| test_description='bounds-checking of access to mmapped on-disk file formats' |
| . ./test-lib.sh |
| |
| clear_base () { |
| test_when_finished 'restore_base' && |
| rm -f $base |
| } |
| |
| restore_base () { |
| cp base-backup/* .git/objects/pack/ |
| } |
| |
| do_pack () { |
| pack_objects=$1; shift |
| sha1=$( |
| for i in $pack_objects |
| do |
| echo $i |
| done | git pack-objects "$@" .git/objects/pack/pack |
| ) && |
| pack=.git/objects/pack/pack-$sha1.pack && |
| idx=.git/objects/pack/pack-$sha1.idx && |
| chmod +w $pack $idx && |
| test_when_finished 'rm -f "$pack" "$idx"' |
| } |
| |
| munge () { |
| printf "$3" | dd of="$1" bs=1 conv=notrunc seek=$2 |
| } |
| |
| # Offset in a v2 .idx to its initial and extended offset tables. For an index |
| # with "nr" objects, this is: |
| # |
| # magic(4) + version(4) + fan-out(4*256) + sha1s(20*nr) + crc(4*nr), |
| # |
| # for the initial, and another ofs(4*nr) past that for the extended. |
| # |
| ofs_table () { |
| echo $((4 + 4 + 4*256 + $(test_oid rawsz)*$1 + 4*$1)) |
| } |
| extended_table () { |
| echo $(($(ofs_table "$1") + 4*$1)) |
| } |
| |
| test_expect_success 'setup' ' |
| test_oid_cache <<-EOF |
| oid000 sha1:1485 |
| oid000 sha256:4222 |
| |
| oidfff sha1:74 |
| oidfff sha256:1350 |
| EOF |
| ' |
| |
| test_expect_success 'set up base packfile and variables' ' |
| # the hash of this content starts with ff, which |
| # makes some later computations much simpler |
| echo $(test_oid oidfff) >file && |
| git add file && |
| git commit -m base && |
| git repack -ad && |
| base=$(echo .git/objects/pack/*) && |
| chmod +w $base && |
| mkdir base-backup && |
| cp $base base-backup/ && |
| object=$(git rev-parse HEAD:file) |
| ' |
| |
| test_expect_success 'pack/index object count mismatch' ' |
| do_pack $object && |
| munge $pack 8 "\377\0\0\0" && |
| clear_base && |
| |
| # We enumerate the objects from the completely-fine |
| # .idx, but notice later that the .pack is bogus |
| # and fail to show any data. |
| echo "$object missing" >expect && |
| git cat-file --batch-all-objects --batch-check >actual && |
| test_cmp expect actual && |
| |
| # ...and here fail to load the object (without segfaulting), |
| # but fallback to a good copy if available. |
| test_must_fail git cat-file blob $object && |
| restore_base && |
| git cat-file blob $object >actual && |
| test_cmp file actual && |
| |
| # ...and make sure that index-pack --verify, which has its |
| # own reading routines, does not segfault. |
| test_must_fail git index-pack --verify $pack |
| ' |
| |
| test_expect_success 'matched bogus object count' ' |
| do_pack $object && |
| munge $pack 8 "\377\0\0\0" && |
| munge $idx $((255 * 4)) "\377\0\0\0" && |
| clear_base && |
| |
| # Unlike above, we should notice early that the .idx is totally |
| # bogus, and not even enumerate its contents. |
| git cat-file --batch-all-objects --batch-check >actual && |
| test_must_be_empty actual && |
| |
| # But as before, we can do the same object-access checks. |
| test_must_fail git cat-file blob $object && |
| restore_base && |
| git cat-file blob $object >actual && |
| test_cmp file actual && |
| |
| test_must_fail git index-pack --verify $pack |
| ' |
| |
| # Note that we cannot check the fallback case for these |
| # further .idx tests, as we notice the problem in functions |
| # whose interface doesn't allow an error return (like use_pack()), |
| # and thus we just die(). |
| # |
| # There's also no point in doing enumeration tests, as |
| # we are munging offsets here, which are about looking up |
| # specific objects. |
| |
| test_expect_success 'bogus object offset (v1)' ' |
| do_pack $object --index-version=1 && |
| munge $idx $((4 * 256)) "\377\0\0\0" && |
| clear_base && |
| test_must_fail git cat-file blob $object && |
| test_must_fail git index-pack --verify $pack |
| ' |
| |
| test_expect_success 'bogus object offset (v2, no msb)' ' |
| do_pack $object --index-version=2 && |
| munge $idx $(ofs_table 1) "\0\377\0\0" && |
| clear_base && |
| test_must_fail git cat-file blob $object && |
| test_must_fail git index-pack --verify $pack |
| ' |
| |
| test_expect_success 'bogus offset into v2 extended table' ' |
| do_pack $object --index-version=2 && |
| munge $idx $(ofs_table 1) "\377\0\0\0" && |
| clear_base && |
| test_must_fail git cat-file blob $object && |
| test_must_fail git index-pack --verify $pack |
| ' |
| |
| test_expect_success 'bogus offset inside v2 extended table' ' |
| # We need two objects here, so we can plausibly require |
| # an extended table (if the first object were larger than 2^31). |
| # |
| # Note that the value is important here. We want $object as |
| # the second entry in sorted-hash order. The hash of this object starts |
| # with "000", which sorts before that of $object (which starts |
| # with "fff"). |
| second=$(test_oid oid000 | git hash-object -w --stdin) && |
| do_pack "$object $second" --index-version=2 && |
| |
| # We have to make extra room for the table, so we cannot |
| # just munge in place as usual. |
| { |
| dd if=$idx bs=1 count=$(($(ofs_table 2) + 4)) && |
| printf "\200\0\0\0" && |
| printf "\377\0\0\0\0\0\0\0" && |
| dd if=$idx bs=1 skip=$(extended_table 2) |
| } >tmp && |
| mv tmp "$idx" && |
| clear_base && |
| test_must_fail git cat-file blob $object && |
| test_must_fail git index-pack --verify $pack |
| ' |
| |
| test_expect_success 'bogus OFS_DELTA in packfile' ' |
| # Generate a pack with a delta in it. |
| base=$(test-tool genrandom foo 3000 | git hash-object --stdin -w) && |
| delta=$(test-tool genrandom foo 2000 | git hash-object --stdin -w) && |
| do_pack "$base $delta" --delta-base-offset && |
| rm -f .git/objects/??/* && |
| |
| # Double check that we have the delta we expect. |
| echo $base >expect && |
| echo $delta | git cat-file --batch-check="%(deltabase)" >actual && |
| test_cmp expect actual && |
| |
| # Now corrupt it. We assume the varint size for the delta is small |
| # enough to fit in the first byte (which it should be, since it |
| # is a pure deletion from the base), and that original ofs_delta |
| # takes 2 bytes (which it should, as it should be ~3000). |
| ofs=$(git show-index <$idx | grep $delta | cut -d" " -f1) && |
| munge $pack $(($ofs + 1)) "\177\377" && |
| test_must_fail git cat-file blob $delta >/dev/null |
| ' |
| |
| test_done |