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[Qemu-block] [PATCH v3 3/7] block: fix data type casting for crypto payl
From: |
Daniel P. Berrange |
Subject: |
[Qemu-block] [PATCH v3 3/7] block: fix data type casting for crypto payload offset |
Date: |
Tue, 12 Sep 2017 12:28:51 +0100 |
The crypto APIs report the offset of the data payload as an uint64_t
type, but the block driver is casting to size_t or ssize_t which will
potentially truncate.
Most of the block APIs use int64_t for offsets meanwhile, so even if
using uint64_t in the crypto block driver we are still at risk of
truncation.
Change the block crypto driver to use uint64_t, but add asserts that
the value is less than INT64_MAX.
Signed-off-by: Daniel P. Berrange <address@hidden>
---
block/crypto.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)
diff --git a/block/crypto.c b/block/crypto.c
index cc8afe0e0d..d68cbac2ac 100644
--- a/block/crypto.c
+++ b/block/crypto.c
@@ -364,8 +364,9 @@ static int block_crypto_truncate(BlockDriverState *bs,
int64_t offset,
PreallocMode prealloc, Error **errp)
{
BlockCrypto *crypto = bs->opaque;
- size_t payload_offset =
+ uint64_t payload_offset =
qcrypto_block_get_payload_offset(crypto->block);
+ assert(payload_offset < (INT64_MAX - offset));
offset += payload_offset;
@@ -391,8 +392,9 @@ block_crypto_co_readv(BlockDriverState *bs, int64_t
sector_num,
uint8_t *cipher_data = NULL;
QEMUIOVector hd_qiov;
int ret = 0;
- size_t payload_offset =
+ uint64_t payload_offset =
qcrypto_block_get_payload_offset(crypto->block) / 512;
+ assert(payload_offset < (INT64_MAX / 512));
qemu_iovec_init(&hd_qiov, qiov->niov);
@@ -458,8 +460,9 @@ block_crypto_co_writev(BlockDriverState *bs, int64_t
sector_num,
uint8_t *cipher_data = NULL;
QEMUIOVector hd_qiov;
int ret = 0;
- size_t payload_offset =
+ uint64_t payload_offset =
qcrypto_block_get_payload_offset(crypto->block) / 512;
+ assert(payload_offset < (INT64_MAX / 512));
qemu_iovec_init(&hd_qiov, qiov->niov);
@@ -520,7 +523,9 @@ static int64_t block_crypto_getlength(BlockDriverState *bs)
BlockCrypto *crypto = bs->opaque;
int64_t len = bdrv_getlength(bs->file->bs);
- ssize_t offset = qcrypto_block_get_payload_offset(crypto->block);
+ uint64_t offset = qcrypto_block_get_payload_offset(crypto->block);
+ assert(offset < INT64_MAX);
+ assert(offset < len);
len -= offset;
--
2.13.5