qemu/0405-qcow1-Stricter-backing...

48 lines
1.6 KiB
Diff

From: Kevin Wolf <kwolf@redhat.com>
Date: Thu, 8 May 2014 13:35:09 +0200
Subject: [PATCH] qcow1: Stricter backing file length check
Like qcow2 since commit 6d33e8e7, error out on invalid lengths instead
of silently truncating them to 1023.
Also don't rely on bdrv_pread() catching integer overflows that make len
negative, but use unsigned variables in the first place.
Cc: qemu-stable@nongnu.org
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Benoit Canet <benoit@irqsave.net>
(cherry picked from commit d66e5cee002c471b78139228a4e7012736b375f9)
Conflicts:
tests/qemu-iotests/092
tests/qemu-iotests/092.out
---
block/qcow.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/block/qcow.c b/block/qcow.c
index 4946bbf..9439c73 100644
--- a/block/qcow.c
+++ b/block/qcow.c
@@ -96,7 +96,8 @@ static int qcow_probe(const uint8_t *buf, int buf_size, const char *filename)
static int qcow_open(BlockDriverState *bs, QDict *options, int flags)
{
BDRVQcowState *s = bs->opaque;
- int len, i, shift, ret;
+ unsigned int len, i, shift;
+ int ret;
QCowHeader header;
ret = bdrv_pread(bs->file, 0, &header, sizeof(header));
@@ -198,7 +199,9 @@ static int qcow_open(BlockDriverState *bs, QDict *options, int flags)
if (header.backing_file_offset != 0) {
len = header.backing_file_size;
if (len > 1023) {
- len = 1023;
+ error_report("Backing file name too long");
+ ret = -EINVAL;
+ goto fail;
}
ret = bdrv_pread(bs->file, header.backing_file_offset,
bs->backing_file, len);