From 31376555c7b447afb1bf9084eacbb8f566ff6b9d Mon Sep 17 00:00:00 2001 From: "Daniel P. Berrange" Date: Wed, 27 Sep 2017 13:53:37 +0100 Subject: block: fix data type casting for crypto payload offset 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. Reviewed-by: Max Reitz Reviewed-by: Eric Blake Signed-off-by: Daniel P. Berrange Message-id: 20170927125340.12360-4-berrange@redhat.com Signed-off-by: Max Reitz --- block/crypto.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) (limited to 'block') diff --git a/block/crypto.c b/block/crypto.c index 684cabe..61f5d77 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; @@ -395,8 +396,9 @@ 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); @@ -462,8 +464,9 @@ 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); @@ -524,7 +527,9 @@ 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; -- cgit v1.1