diff options
| -rw-r--r-- | block/io.c | 10 | ||||
| -rw-r--r-- | include/qemu/iov.h | 2 | ||||
| -rw-r--r-- | util/iov.c | 25 |
3 files changed, 31 insertions, 6 deletions
diff --git a/block/io.c b/block/io.c index 23abdae794..ab953bd58f 100644 --- a/block/io.c +++ b/block/io.c @@ -1680,13 +1680,17 @@ static bool bdrv_pad_request(BlockDriverState *bs, int64_t *offset, unsigned int *bytes, BdrvRequestPadding *pad) { + int ret; + if (!bdrv_init_padding(bs, *offset, *bytes, pad)) { return false; } - qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head, - *qiov, *qiov_offset, *bytes, - pad->buf + pad->buf_len - pad->tail, pad->tail); + ret = qemu_iovec_init_extended(&pad->local_qiov, pad->buf, pad->head, + *qiov, *qiov_offset, *bytes, + pad->buf + pad->buf_len - pad->tail, + pad->tail); + assert(ret == 0); *bytes += pad->head + pad->tail; *offset -= pad->head; *qiov = &pad->local_qiov; diff --git a/include/qemu/iov.h b/include/qemu/iov.h index b6b283a5e5..9330746680 100644 --- a/include/qemu/iov.h +++ b/include/qemu/iov.h @@ -222,7 +222,7 @@ static inline void *qemu_iovec_buf(QEMUIOVector *qiov) void qemu_iovec_init(QEMUIOVector *qiov, int alloc_hint); void qemu_iovec_init_external(QEMUIOVector *qiov, struct iovec *iov, int niov); -void qemu_iovec_init_extended( +int qemu_iovec_init_extended( QEMUIOVector *qiov, void *head_buf, size_t head_len, QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len, diff --git a/util/iov.c b/util/iov.c index f3a9e92a37..58c7b3eeee 100644 --- a/util/iov.c +++ b/util/iov.c @@ -415,7 +415,7 @@ int qemu_iovec_subvec_niov(QEMUIOVector *qiov, size_t offset, size_t len) * Compile new iovec, combining @head_buf buffer, sub-qiov of @mid_qiov, * and @tail_buf buffer into new qiov. */ -void qemu_iovec_init_extended( +int qemu_iovec_init_extended( QEMUIOVector *qiov, void *head_buf, size_t head_len, QEMUIOVector *mid_qiov, size_t mid_offset, size_t mid_len, @@ -425,12 +425,24 @@ void qemu_iovec_init_extended( int total_niov, mid_niov = 0; struct iovec *p, *mid_iov = NULL; + assert(mid_qiov->niov <= IOV_MAX); + + if (SIZE_MAX - head_len < mid_len || + SIZE_MAX - head_len - mid_len < tail_len) + { + return -EINVAL; + } + if (mid_len) { mid_iov = qiov_slice(mid_qiov, mid_offset, mid_len, &mid_head, &mid_tail, &mid_niov); } total_niov = !!head_len + mid_niov + !!tail_len; + if (total_niov > IOV_MAX) { + return -EINVAL; + } + if (total_niov == 1) { qemu_iovec_init_buf(qiov, NULL, 0); p = &qiov->local_iov; @@ -459,6 +471,8 @@ void qemu_iovec_init_extended( p->iov_base = tail_buf; p->iov_len = tail_len; } + + return 0; } /* @@ -492,7 +506,14 @@ bool qemu_iovec_is_zero(QEMUIOVector *qiov, size_t offset, size_t bytes) void qemu_iovec_init_slice(QEMUIOVector *qiov, QEMUIOVector *source, size_t offset, size_t len) { - qemu_iovec_init_extended(qiov, NULL, 0, source, offset, len, NULL, 0); + int ret; + + assert(source->size >= len); + assert(source->size - len >= offset); + + /* We shrink the request, so we can't overflow neither size_t nor MAX_IOV */ + ret = qemu_iovec_init_extended(qiov, NULL, 0, source, offset, len, NULL, 0); + assert(ret == 0); } void qemu_iovec_destroy(QEMUIOVector *qiov) |