From c7e7244b82ad174a8ca51a385e6ad2eb508261d8 Mon Sep 17 00:00:00 2001 From: Fan Zhang Date: Fri, 4 Jan 2019 11:22:45 +0000 Subject: [PATCH] vhost/crypto: fix possible dead loop This patch fixes a possible infinite loop caused by incorrect descriptor chain created by the driver. Fixes: 3bb595ecd682 ("vhost/crypto: add request handler") Cc: stable@dpdk.org Signed-off-by: Fan Zhang Reviewed-by: Maxime Coquelin --- lib/librte_vhost/vhost_crypto.c | 121 ++++++++++++++++++++++---------- 1 file changed, 82 insertions(+), 39 deletions(-) diff --git a/lib/librte_vhost/vhost_crypto.c b/lib/librte_vhost/vhost_crypto.c index 598196fb7f..e12458ce09 100644 --- a/lib/librte_vhost/vhost_crypto.c +++ b/lib/librte_vhost/vhost_crypto.c @@ -467,12 +467,17 @@ vhost_crypto_msg_post_handler(int vid, void *msg) } static __rte_always_inline struct vring_desc * -find_write_desc(struct vring_desc *head, struct vring_desc *desc) +find_write_desc(struct vring_desc *head, struct vring_desc *desc, + uint32_t *nb_descs) { if (desc->flags & VRING_DESC_F_WRITE) return desc; while (desc->flags & VRING_DESC_F_NEXT) { + if (unlikely(*nb_descs == 0)) + return NULL; + (*nb_descs)--; + desc = &head[desc->next]; if (desc->flags & VRING_DESC_F_WRITE) return desc; @@ -482,13 +487,18 @@ find_write_desc(struct vring_desc *head, struct vring_desc *desc) } static struct virtio_crypto_inhdr * -reach_inhdr(struct vhost_crypto_data_req *vc_req, struct vring_desc *desc) +reach_inhdr(struct vhost_crypto_data_req *vc_req, struct vring_desc *desc, + uint32_t *nb_descs) { uint64_t dlen; struct virtio_crypto_inhdr *inhdr; - while (desc->flags & VRING_DESC_F_NEXT) + while (desc->flags & VRING_DESC_F_NEXT) { + if (unlikely(*nb_descs == 0)) + return NULL; + (*nb_descs)--; desc = &vc_req->head[desc->next]; + } dlen = desc->len; inhdr = IOVA_TO_VVA(struct virtio_crypto_inhdr *, vc_req, desc->addr, @@ -501,15 +511,16 @@ reach_inhdr(struct vhost_crypto_data_req *vc_req, struct vring_desc *desc) static __rte_always_inline int move_desc(struct vring_desc *head, struct vring_desc **cur_desc, - uint32_t size) + uint32_t size, uint32_t *nb_descs) { struct vring_desc *desc = *cur_desc; - int left = size; - - rte_prefetch0(&head[desc->next]); - left -= desc->len; + int left = size - desc->len; while ((desc->flags & VRING_DESC_F_NEXT) && left > 0) { + (*nb_descs)--; + if (unlikely(*nb_descs == 0)) + return -1; + desc = &head[desc->next]; rte_prefetch0(&head[desc->next]); left -= desc->len; @@ -518,7 +529,10 @@ move_desc(struct vring_desc *head, struct vring_desc **cur_desc, if (unlikely(left > 0)) return -1; - *cur_desc = &head[desc->next]; + if (unlikely(*nb_descs == 0)) + *cur_desc = NULL; + else + *cur_desc = &head[desc->next]; return 0; } @@ -540,7 +554,7 @@ get_data_ptr(struct vhost_crypto_data_req *vc_req, struct vring_desc *cur_desc, static int copy_data(void *dst_data, struct vhost_crypto_data_req *vc_req, - struct vring_desc **cur_desc, uint32_t size) + struct vring_desc **cur_desc, uint32_t size, uint32_t *nb_descs) { struct vring_desc *desc = *cur_desc; uint64_t remain, addr, dlen, len; @@ -549,7 +563,6 @@ copy_data(void *dst_data, struct vhost_crypto_data_req *vc_req, uint8_t *src; int left = size; - rte_prefetch0(&vc_req->head[desc->next]); to_copy = RTE_MIN(desc->len, (uint32_t)left); dlen = to_copy; src = IOVA_TO_VVA(uint8_t *, vc_req, desc->addr, &dlen, @@ -583,6 +596,12 @@ copy_data(void *dst_data, struct vhost_crypto_data_req *vc_req, left -= to_copy; while ((desc->flags & VRING_DESC_F_NEXT) && left > 0) { + if (unlikely(*nb_descs == 0)) { + VC_LOG_ERR("Invalid descriptors"); + return -1; + } + (*nb_descs)--; + desc = &vc_req->head[desc->next]; rte_prefetch0(&vc_req->head[desc->next]); to_copy = RTE_MIN(desc->len, (uint32_t)left); @@ -625,7 +644,10 @@ copy_data(void *dst_data, struct vhost_crypto_data_req *vc_req, return -1; } - *cur_desc = &vc_req->head[desc->next]; + if (unlikely(*nb_descs == 0)) + *cur_desc = NULL; + else + *cur_desc = &vc_req->head[desc->next]; return 0; } @@ -685,7 +707,8 @@ prepare_write_back_data(struct vhost_crypto_data_req *vc_req, struct vhost_crypto_writeback_data **end_wb_data, uint8_t *src, uint32_t offset, - uint64_t write_back_len) + uint64_t write_back_len, + uint32_t *nb_descs) { struct vhost_crypto_writeback_data *wb_data, *head; struct vring_desc *desc = *cur_desc; @@ -732,6 +755,12 @@ prepare_write_back_data(struct vhost_crypto_data_req *vc_req, offset -= desc->len; while (write_back_len) { + if (unlikely(*nb_descs == 0)) { + VC_LOG_ERR("Invalid descriptors"); + goto error_exit; + } + (*nb_descs)--; + desc = &vc_req->head[desc->next]; if (unlikely(!(desc->flags & VRING_DESC_F_WRITE))) { VC_LOG_ERR("incorrect descriptor"); @@ -771,7 +800,10 @@ prepare_write_back_data(struct vhost_crypto_data_req *vc_req, wb_data->next = NULL; } - *cur_desc = &vc_req->head[desc->next]; + if (unlikely(*nb_descs == 0)) + *cur_desc = NULL; + else + *cur_desc = &vc_req->head[desc->next]; *end_wb_data = wb_data; @@ -788,7 +820,8 @@ static uint8_t prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, struct vhost_crypto_data_req *vc_req, struct virtio_crypto_cipher_data_req *cipher, - struct vring_desc *cur_desc) + struct vring_desc *cur_desc, + uint32_t *nb_descs) { struct vring_desc *desc = cur_desc; struct vhost_crypto_writeback_data *ewb = NULL; @@ -798,8 +831,8 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, /* prepare */ /* iv */ - if (unlikely(copy_data(iv_data, vc_req, &desc, - cipher->para.iv_len) < 0)) { + if (unlikely(copy_data(iv_data, vc_req, &desc, cipher->para.iv_len, + nb_descs) < 0)) { ret = VIRTIO_CRYPTO_BADMSG; goto error_exit; } @@ -819,7 +852,7 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, } if (unlikely(move_desc(vc_req->head, &desc, - cipher->para.src_data_len) < 0)) { + cipher->para.src_data_len, nb_descs) < 0)) { VC_LOG_ERR("Incorrect descriptor"); ret = VIRTIO_CRYPTO_ERR; goto error_exit; @@ -836,8 +869,8 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, goto error_exit; } if (unlikely(copy_data(rte_pktmbuf_mtod(m_src, uint8_t *), - vc_req, &desc, cipher->para.src_data_len) - < 0)) { + vc_req, &desc, cipher->para.src_data_len, + nb_descs) < 0)) { ret = VIRTIO_CRYPTO_BADMSG; goto error_exit; } @@ -848,7 +881,7 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, } /* dst */ - desc = find_write_desc(vc_req->head, desc); + desc = find_write_desc(vc_req->head, desc, nb_descs); if (unlikely(!desc)) { VC_LOG_ERR("Cannot find write location"); ret = VIRTIO_CRYPTO_BADMSG; @@ -867,7 +900,7 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, } if (unlikely(move_desc(vc_req->head, &desc, - cipher->para.dst_data_len) < 0)) { + cipher->para.dst_data_len, nb_descs) < 0)) { VC_LOG_ERR("Incorrect descriptor"); ret = VIRTIO_CRYPTO_ERR; goto error_exit; @@ -878,7 +911,7 @@ prepare_sym_cipher_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, case RTE_VHOST_CRYPTO_ZERO_COPY_DISABLE: vc_req->wb = prepare_write_back_data(vc_req, &desc, &ewb, rte_pktmbuf_mtod(m_src, uint8_t *), 0, - cipher->para.dst_data_len); + cipher->para.dst_data_len, nb_descs); if (unlikely(vc_req->wb == NULL)) { ret = VIRTIO_CRYPTO_ERR; goto error_exit; @@ -920,7 +953,8 @@ static uint8_t prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, struct vhost_crypto_data_req *vc_req, struct virtio_crypto_alg_chain_data_req *chain, - struct vring_desc *cur_desc) + struct vring_desc *cur_desc, + uint32_t *nb_descs) { struct vring_desc *desc = cur_desc, *digest_desc; struct vhost_crypto_writeback_data *ewb = NULL, *ewb2 = NULL; @@ -933,7 +967,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, /* prepare */ /* iv */ if (unlikely(copy_data(iv_data, vc_req, &desc, - chain->para.iv_len) < 0)) { + chain->para.iv_len, nb_descs) < 0)) { ret = VIRTIO_CRYPTO_BADMSG; goto error_exit; } @@ -954,7 +988,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, } if (unlikely(move_desc(vc_req->head, &desc, - chain->para.src_data_len) < 0)) { + chain->para.src_data_len, nb_descs) < 0)) { VC_LOG_ERR("Incorrect descriptor"); ret = VIRTIO_CRYPTO_ERR; goto error_exit; @@ -970,7 +1004,8 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, goto error_exit; } if (unlikely(copy_data(rte_pktmbuf_mtod(m_src, uint8_t *), - vc_req, &desc, chain->para.src_data_len)) < 0) { + vc_req, &desc, chain->para.src_data_len, + nb_descs)) < 0) { ret = VIRTIO_CRYPTO_BADMSG; goto error_exit; } @@ -982,7 +1017,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, } /* dst */ - desc = find_write_desc(vc_req->head, desc); + desc = find_write_desc(vc_req->head, desc, nb_descs); if (unlikely(!desc)) { VC_LOG_ERR("Cannot find write location"); ret = VIRTIO_CRYPTO_BADMSG; @@ -1001,7 +1036,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, } if (unlikely(move_desc(vc_req->head, &desc, - chain->para.dst_data_len) < 0)) { + chain->para.dst_data_len, nb_descs) < 0)) { VC_LOG_ERR("Incorrect descriptor"); ret = VIRTIO_CRYPTO_ERR; goto error_exit; @@ -1018,7 +1053,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, } if (unlikely(move_desc(vc_req->head, &desc, - chain->para.hash_result_len) < 0)) { + chain->para.hash_result_len, nb_descs) < 0)) { VC_LOG_ERR("Incorrect descriptor"); ret = VIRTIO_CRYPTO_ERR; goto error_exit; @@ -1030,7 +1065,7 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, rte_pktmbuf_mtod(m_src, uint8_t *), chain->para.cipher_start_src_offset, chain->para.dst_data_len - - chain->para.cipher_start_src_offset); + chain->para.cipher_start_src_offset, nb_descs); if (unlikely(vc_req->wb == NULL)) { ret = VIRTIO_CRYPTO_ERR; goto error_exit; @@ -1043,14 +1078,15 @@ prepare_sym_chain_op(struct vhost_crypto *vcrypto, struct rte_crypto_op *op, /** create a wb_data for digest */ ewb->next = prepare_write_back_data(vc_req, &desc, &ewb2, - digest_addr, 0, chain->para.hash_result_len); + digest_addr, 0, chain->para.hash_result_len, + nb_descs); if (unlikely(ewb->next == NULL)) { ret = VIRTIO_CRYPTO_ERR; goto error_exit; } if (unlikely(copy_data(digest_addr, vc_req, &digest_desc, - chain->para.hash_result_len)) < 0) { + chain->para.hash_result_len, nb_descs)) < 0) { ret = VIRTIO_CRYPTO_BADMSG; goto error_exit; } @@ -1109,6 +1145,7 @@ vhost_crypto_process_one_req(struct vhost_crypto *vcrypto, struct vring_desc *desc = NULL; uint64_t session_id; uint64_t dlen; + uint32_t nb_descs = vq->size; int err = 0; vc_req->desc_idx = desc_idx; @@ -1117,6 +1154,10 @@ vhost_crypto_process_one_req(struct vhost_crypto *vcrypto, if (likely(head->flags & VRING_DESC_F_INDIRECT)) { dlen = head->len; + nb_descs = dlen / sizeof(struct vring_desc); + /* drop invalid descriptors */ + if (unlikely(nb_descs > vq->size)) + return -1; desc = IOVA_TO_VVA(struct vring_desc *, vc_req, head->addr, &dlen, VHOST_ACCESS_RO); if (unlikely(!desc || dlen != head->len)) @@ -1139,8 +1180,8 @@ vhost_crypto_process_one_req(struct vhost_crypto *vcrypto, goto error_exit; case RTE_VHOST_CRYPTO_ZERO_COPY_DISABLE: req = &tmp_req; - if (unlikely(copy_data(req, vc_req, &desc, sizeof(*req)) - < 0)) { + if (unlikely(copy_data(req, vc_req, &desc, sizeof(*req), + &nb_descs) < 0)) { err = VIRTIO_CRYPTO_BADMSG; VC_LOG_ERR("Invalid descriptor"); goto error_exit; @@ -1153,7 +1194,7 @@ vhost_crypto_process_one_req(struct vhost_crypto *vcrypto, } } else { if (unlikely(move_desc(vc_req->head, &desc, - sizeof(*req)) < 0)) { + sizeof(*req), &nb_descs) < 0)) { VC_LOG_ERR("Incorrect descriptor"); goto error_exit; } @@ -1194,11 +1235,13 @@ vhost_crypto_process_one_req(struct vhost_crypto *vcrypto, break; case VIRTIO_CRYPTO_SYM_OP_CIPHER: err = prepare_sym_cipher_op(vcrypto, op, vc_req, - &req->u.sym_req.u.cipher, desc); + &req->u.sym_req.u.cipher, desc, + &nb_descs); break; case VIRTIO_CRYPTO_SYM_OP_ALGORITHM_CHAINING: err = prepare_sym_chain_op(vcrypto, op, vc_req, - &req->u.sym_req.u.chain, desc); + &req->u.sym_req.u.chain, desc, + &nb_descs); break; } if (unlikely(err != 0)) { @@ -1216,7 +1259,7 @@ vhost_crypto_process_one_req(struct vhost_crypto *vcrypto, error_exit: - inhdr = reach_inhdr(vc_req, desc); + inhdr = reach_inhdr(vc_req, desc, &nb_descs); if (likely(inhdr != NULL)) inhdr->status = (uint8_t)err; -- 2.20.1