Because the 'size_t' type is 4 bytes in 32-bit platform, which is the same with 'int'. It's easy to make 'max_len' to zero when integer overflow and then cause heap overflow if 'max_len' is zero.
Using uint_64 instead of size_t to avoid the integer overflow. Cc: qemu-sta...@nongnu.org Reported-by: Li Qiang <liqiang...@360.cn> Signed-off-by: Gonglei <arei.gong...@huawei.com> Tested-by: Li Qiang <liqiang...@360.cn> --- hw/virtio/virtio-crypto.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c index 978bb98..fc30bc3 100644 --- a/hw/virtio/virtio-crypto.c +++ b/hw/virtio/virtio-crypto.c @@ -416,7 +416,7 @@ virtio_crypto_sym_op_helper(VirtIODevice *vdev, uint32_t hash_start_src_offset = 0, len_to_hash = 0; uint32_t cipher_start_src_offset = 0, len_to_cipher = 0; - size_t max_len, curr_size = 0; + uint64_t max_len, curr_size = 0; size_t s; /* Plain cipher */ @@ -441,7 +441,7 @@ virtio_crypto_sym_op_helper(VirtIODevice *vdev, return NULL; } - max_len = iv_len + aad_len + src_len + dst_len + hash_result_len; + max_len = (uint64_t)iv_len + aad_len + src_len + dst_len + hash_result_len; if (unlikely(max_len > vcrypto->conf.max_size)) { virtio_error(vdev, "virtio-crypto too big length"); return NULL; -- 1.8.3.1