name-hash: fix buffer overrun

Add check for the end of the entries for the thread partition.
Add test for lazy init name hash with specific directory structure

The lazy init hash name was causing a buffer overflow when the last
entry in the index was multiple folder deep with parent folders that
did not have any files in them.

This adds a test for the boundary condition of the thread partitions
with the folder structure that was triggering the buffer overflow.

The fix was to check if it is the last entry for the thread partition
in the handle_range_dir and not try to use the next entry in the cache.

Signed-off-by: Kevin Willford <kewillf@microsoft.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Jeff Hostetler <jeffhost@microsoft.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This commit is contained in:
Kevin Willford 2017-03-31 17:32:14 +00:00 committed by Junio C Hamano
parent 41b3eb4a6b
commit 2a1bd45b2e
2 changed files with 22 additions and 1 deletions

View File

@ -342,7 +342,9 @@ static int handle_range_dir(
* Scan forward in the index array for index entries having the same
* path prefix (that are also in this directory).
*/
if (strncmp(istate->cache[k_start + 1]->name, prefix->buf, prefix->len) > 0)
if (k_start + 1 >= k_end)
k = k_end;
else if (strncmp(istate->cache[k_start + 1]->name, prefix->buf, prefix->len) > 0)
k = k_start + 1;
else if (strncmp(istate->cache[k_end - 1]->name, prefix->buf, prefix->len) == 0)
k = k_end;

View File

@ -0,0 +1,19 @@
#!/bin/sh
test_description='Test the lazy init name hash with various folder structures'
. ./test-lib.sh
test_expect_success 'no buffer overflow in lazy_init_name_hash' '
(
test_seq 2000 | sed "s/^/a_/"
echo b/b/b
test_seq 2000 | sed "s/^/c_/"
test_seq 50 | sed "s/^/d_/" | tr "\n" "/"; echo d
) |
sed -e "s/^/100644 $EMPTY_BLOB /" |
git update-index --index-info &&
test-lazy-init-name-hash -m
'
test_done