Re: [PATCH v3 2/3] commit-graph: fix buffer read-overflow
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Dec 9, 2018, 04:01 UTC
- Message-ID
- <xmqqsgz74acm.fsf@gitster-ct.c.googlers.com>
- In-Reply-To
- <675d58ecea2f315bd05d2a21f6a473e9de1105a0.1544221121.git.steadmon@google.com>
Josh Steadmon <steadmon@google.com> writes:
Show 21 quoted lines
> diff --git a/t/t5318-commit-graph.sh b/t/t5318-commit-graph.sh
> index 5fe21db99f..5b6b44b78e 100755
> --- a/t/t5318-commit-graph.sh
> +++ b/t/t5318-commit-graph.sh
> @@ -366,24 +366,30 @@ GRAPH_OCTOPUS_DATA_OFFSET=$(($GRAPH_COMMIT_DATA_OFFSET + \
> GRAPH_BYTE_OCTOPUS=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4))
> GRAPH_BYTE_FOOTER=$(($GRAPH_OCTOPUS_DATA_OFFSET + 4 * $NUM_OCTOPUS_EDGES))
>
> -# usage: corrupt_graph_and_verify <position> <data> <string>
> +# usage: corrupt_graph_and_verify <position> <data> <string> [<zero_pos>]
> # Manipulates the commit-graph file at the position
> -# by inserting the data, then runs 'git commit-graph verify'
> +# by inserting the data, optionally zeroing the file
> +# starting at <zero_pos>, then runs 'git commit-graph verify'
> # and places the output in the file 'err'. Test 'err' for
> # the given string.
> corrupt_graph_and_verify() {
> pos=$1
> data="${2:-\0}"
> grepstr=$3
> + orig_size=$(stat --format=%s $objdir/info/commit-graph)"stat(1)" is not so portable, so you'll get complaints from minority platform users later. So is "truncate(1)".
Show 22 quoted lines
> + zero_pos=${4:-${orig_size}}
> cd "$TRASH_DIRECTORY/full" &&
> test_when_finished mv commit-graph-backup $objdir/info/commit-graph &&
> cp $objdir/info/commit-graph commit-graph-backup &&
> printf "$data" | dd of="$objdir/info/commit-graph" bs=1 seek="$pos" conv=notrunc &&
> + truncate --size=$zero_pos $objdir/info/commit-graph &&
> + truncate --size=$orig_size $objdir/info/commit-graph &&
> test_must_fail git commit-graph verify 2>test_err &&
> grep -v "^+" test_err >err
> test_i18ngrep "$grepstr" err
> }
>
> +
> test_expect_success 'detect bad signature' '
> corrupt_graph_and_verify 0 "\0" \
> "graph signature"
> @@ -484,6 +490,11 @@ test_expect_success 'detect invalid checksum hash' '
> "incorrect checksum"
> '
>
> +test_expect_success 'detect incorrect chunk count' '
> + corrupt_graph_and_verify $GRAPH_BYTE_CHUNK_COUNT "\xff" \Implementations of printf(1) may not grok "\xff" as a valid representation of "\377". The shell built-in of dash(1) for example would not work with this.
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> + "chunk lookup table entry missing" $GRAPH_CHUNK_LOOKUP_OFFSET > +' > + > test_expect_success 'git fsck (checks commit-graph)' ' > cd "$TRASH_DIRECTORY/full" && > git fsck &&