block/vmdk.c | 28 ++++++++++++++++++++-------- tests/qemu-iotests/059 | 2 ++ tests/qemu-iotests/059.out | 4 ++++ 3 files changed, 26 insertions(+), 8 deletions(-)
From: Fam Zheng <fam@euphon.net>
If the text description file is larger than DESC_SIZE, we force the last
byte in the buffer to be 0 and write it out.
This results in a corruption.
Try to allocate a big buffer in this case.
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1923
Signed-off-by: Fam Zheng <fam@euphon.net>
---
block/vmdk.c | 28 ++++++++++++++++++++--------
tests/qemu-iotests/059 | 2 ++
tests/qemu-iotests/059.out | 4 ++++
3 files changed, 26 insertions(+), 8 deletions(-)
diff --git a/block/vmdk.c b/block/vmdk.c
index d87f6d9aaa..d6971c7067 100644
--- a/block/vmdk.c
+++ b/block/vmdk.c
@@ -351,29 +351,41 @@ vmdk_write_cid(BlockDriverState *bs, uint32_t cid)
BDRVVmdkState *s = bs->opaque;
int ret = 0;
- desc = g_malloc0(DESC_SIZE);
- tmp_desc = g_malloc0(DESC_SIZE);
- ret = bdrv_co_pread(bs->file, s->desc_offset, DESC_SIZE, desc, 0);
+ size_t desc_buf_size;
+
+ if (s->desc_offset == 0) {
+ desc_buf_size = bdrv_getlength(bs->file->bs);
+ if (desc_buf_size > 16ULL << 20) {
+ error_report("VMDK description file too big");
+ return -EFBIG;
+ }
+ } else {
+ desc_buf_size = DESC_SIZE;
+ }
+
+ desc = g_malloc0(desc_buf_size);
+ tmp_desc = g_malloc0(desc_buf_size);
+ ret = bdrv_co_pread(bs->file, s->desc_offset, desc_buf_size, desc, 0);
if (ret < 0) {
goto out;
}
- desc[DESC_SIZE - 1] = '\0';
+ desc[desc_buf_size - 1] = '\0';
tmp_str = strstr(desc, "parentCID");
if (tmp_str == NULL) {
ret = -EINVAL;
goto out;
}
- pstrcpy(tmp_desc, DESC_SIZE, tmp_str);
+ pstrcpy(tmp_desc, desc_buf_size, tmp_str);
p_name = strstr(desc, "CID");
if (p_name != NULL) {
p_name += sizeof("CID");
- snprintf(p_name, DESC_SIZE - (p_name - desc), "%" PRIx32 "\n", cid);
- pstrcat(desc, DESC_SIZE, tmp_desc);
+ snprintf(p_name, desc_buf_size - (p_name - desc), "%" PRIx32 "\n", cid);
+ pstrcat(desc, desc_buf_size, tmp_desc);
}
- ret = bdrv_co_pwrite_sync(bs->file, s->desc_offset, DESC_SIZE, desc, 0);
+ ret = bdrv_co_pwrite_sync(bs->file, s->desc_offset, desc_buf_size, desc, 0);
out:
g_free(desc);
diff --git a/tests/qemu-iotests/059 b/tests/qemu-iotests/059
index 2bcb1f7f9c..0634c7bd92 100755
--- a/tests/qemu-iotests/059
+++ b/tests/qemu-iotests/059
@@ -84,6 +84,8 @@ echo
echo "=== Testing big twoGbMaxExtentFlat ==="
_make_test_img -o "subformat=twoGbMaxExtentFlat" 1000G
_img_info --format-specific | _filter_img_info --format-specific
+$QEMU_IO -c "write 990G 512 -P 89" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IO -c "read 990G 512 -P 89" "$TEST_IMG" | _filter_qemu_io
_cleanup_test_img
echo
diff --git a/tests/qemu-iotests/059.out b/tests/qemu-iotests/059.out
index 2b83c0c8b6..275ee7c778 100644
--- a/tests/qemu-iotests/059.out
+++ b/tests/qemu-iotests/059.out
@@ -2032,6 +2032,10 @@ Format specific information:
virtual size: 2147483648
filename: TEST_DIR/t-f500.IMGFMT
format: FLAT
+wrote 512/512 bytes at offset 1063004405760
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+read 512/512 bytes at offset 1063004405760
+512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
=== Testing malformed VMFS extent description line ===
qemu-img: Could not open 'TEST_DIR/t.IMGFMT': Invalid extent line: RW 12582912 VMFS "dummy.IMGFMT" 1
--
2.34.1Am 24.11.2023 um 12:56 hat Fam geschrieben: > From: Fam Zheng <fam@euphon.net> > > If the text description file is larger than DESC_SIZE, we force the last > byte in the buffer to be 0 and write it out. > > This results in a corruption. > > Try to allocate a big buffer in this case. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1923 > > Signed-off-by: Fam Zheng <fam@euphon.net> Thanks, applied to the block branch. But while I'm looking at this function, is there really anything that guarantees that "parentCID" always exists and comes immediately after "CID"? This looks like a questionable assumption to me. Kevin
On Fri, Nov 24, 2023 at 11:56:54AM +0000, Fam wrote: > From: Fam Zheng <fam@euphon.net> > > If the text description file is larger than DESC_SIZE, we force the last > byte in the buffer to be 0 and write it out. > > This results in a corruption. > > Try to allocate a big buffer in this case. > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1923 > > Signed-off-by: Fam Zheng <fam@euphon.net> > --- > block/vmdk.c | 28 ++++++++++++++++++++-------- > tests/qemu-iotests/059 | 2 ++ > tests/qemu-iotests/059.out | 4 ++++ > 3 files changed, 26 insertions(+), 8 deletions(-) Reviewed-by: Eric Blake <eblake@redhat.com> Are we trying to get this into 8.2, since it is a data corruption? -- Eric Blake, Principal Software Engineer Red Hat, Inc. Virtualization: qemu.org | libguestfs.org
Am 27.11.2023 um 16:18 hat Eric Blake geschrieben: > On Fri, Nov 24, 2023 at 11:56:54AM +0000, Fam wrote: > > From: Fam Zheng <fam@euphon.net> > > > > If the text description file is larger than DESC_SIZE, we force the last > > byte in the buffer to be 0 and write it out. > > > > This results in a corruption. > > > > Try to allocate a big buffer in this case. > > > > Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1923 > > > > Signed-off-by: Fam Zheng <fam@euphon.net> > > --- > > block/vmdk.c | 28 ++++++++++++++++++++-------- > > tests/qemu-iotests/059 | 2 ++ > > tests/qemu-iotests/059.out | 4 ++++ > > 3 files changed, 26 insertions(+), 8 deletions(-) > > Reviewed-by: Eric Blake <eblake@redhat.com> > > Are we trying to get this into 8.2, since it is a data corruption? Yes, I've queued it for -rc2. Kevin
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