From de1419e42088e99f8f839710c42aec759e45de77 Mon Sep 17 00:00:00 2001 From: Nicholas Bellinger Date: Thu, 29 Jan 2015 17:21:13 -0800 Subject: [PATCH] vhost/scsi: Fix incorrect early vhost_scsi_handle_vq failures This patch fixes vhost_scsi_handle_vq() failure cases that result in BUG_ON() getting triggered when vhost_scsi_free_cmd() is called, and ->tvc_se_cmd has not been initialized by target_submit_cmd_map_sgls(). It changes tcm_vhost_release_cmd() to use tcm_vhost_cmd->tvc_nexus for obtaining se_session pointer reference. Also, avoid calling put_page() on NULL sg->page entries in vhost_scsi_map_to_sgl() failure path. Cc: Michael S. Tsirkin Cc: Paolo Bonzini Signed-off-by: Nicholas Bellinger --- drivers/vhost/scsi.c | 52 ++++++++++++++++++++++++-------------------- 1 file changed, 29 insertions(+), 23 deletions(-) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 29dfdf66bbc5..62de820ae2f4 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -462,7 +462,7 @@ static void tcm_vhost_release_cmd(struct se_cmd *se_cmd) { struct tcm_vhost_cmd *tv_cmd = container_of(se_cmd, struct tcm_vhost_cmd, tvc_se_cmd); - struct se_session *se_sess = se_cmd->se_sess; + struct se_session *se_sess = tv_cmd->tvc_nexus->tvn_se_sess; int i; if (tv_cmd->tvc_sgl_count) { @@ -864,9 +864,11 @@ vhost_scsi_map_iov_to_sgl(struct tcm_vhost_cmd *cmd, ret = vhost_scsi_map_to_sgl(cmd, sg, sgl_count, &iov[i], cmd->tvc_upages, write); if (ret < 0) { - for (i = 0; i < cmd->tvc_sgl_count; i++) - put_page(sg_page(&cmd->tvc_sgl[i])); - + for (i = 0; i < cmd->tvc_sgl_count; i++) { + struct page *page = sg_page(&cmd->tvc_sgl[i]); + if (page) + put_page(page); + } cmd->tvc_sgl_count = 0; return ret; } @@ -905,9 +907,11 @@ vhost_scsi_map_iov_to_prot(struct tcm_vhost_cmd *cmd, ret = vhost_scsi_map_to_sgl(cmd, prot_sg, prot_sgl_count, &iov[i], cmd->tvc_upages, write); if (ret < 0) { - for (i = 0; i < cmd->tvc_prot_sgl_count; i++) - put_page(sg_page(&cmd->tvc_prot_sgl[i])); - + for (i = 0; i < cmd->tvc_prot_sgl_count; i++) { + struct page *page = sg_page(&cmd->tvc_prot_sgl[i]); + if (page) + put_page(page); + } cmd->tvc_prot_sgl_count = 0; return ret; } @@ -1065,12 +1069,14 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (unlikely(vq->iov[0].iov_len < req_size)) { pr_err("Expecting virtio-scsi header: %zu, got %zu\n", req_size, vq->iov[0].iov_len); - break; + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } ret = memcpy_fromiovecend(req, &vq->iov[0], 0, req_size); if (unlikely(ret)) { vq_err(vq, "Faulted on virtio_scsi_cmd_req\n"); - break; + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } /* virtio-scsi spec requires byte 0 of the lun to be 1 */ @@ -1101,14 +1107,16 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (data_direction != DMA_TO_DEVICE) { vq_err(vq, "Received non zero do_pi_niov" ", but wrong data_direction\n"); - goto err_cmd; + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesout); } else if (v_req_pi.pi_bytesin) { if (data_direction != DMA_FROM_DEVICE) { vq_err(vq, "Received non zero di_pi_niov" ", but wrong data_direction\n"); - goto err_cmd; + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } prot_bytes = vhost32_to_cpu(vq, v_req_pi.pi_bytesin); } @@ -1148,7 +1156,8 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) vq_err(vq, "Received SCSI CDB with command_size: %d that" " exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n", scsi_command_size(cdb), TCM_VHOST_MAX_CDB_SIZE); - goto err_cmd; + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } cmd = vhost_scsi_get_tag(vq, tpg, cdb, tag, lun, task_attr, @@ -1157,7 +1166,8 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (IS_ERR(cmd)) { vq_err(vq, "vhost_scsi_get_tag failed %ld\n", PTR_ERR(cmd)); - goto err_cmd; + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } pr_debug("Allocated tv_cmd: %p exp_data_len: %d, data_direction" @@ -1178,7 +1188,9 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) if (unlikely(ret)) { vq_err(vq, "Failed to map iov to" " prot_sgl\n"); - goto err_free; + tcm_vhost_release_cmd(&cmd->tvc_se_cmd); + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } } if (data_direction != DMA_NONE) { @@ -1187,7 +1199,9 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) data_direction == DMA_FROM_DEVICE); if (unlikely(ret)) { vq_err(vq, "Failed to map iov to sgl\n"); - goto err_free; + tcm_vhost_release_cmd(&cmd->tvc_se_cmd); + vhost_scsi_send_bad_target(vs, vq, head, out); + continue; } } /* @@ -1205,14 +1219,6 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) INIT_WORK(&cmd->work, tcm_vhost_submission_work); queue_work(tcm_vhost_workqueue, &cmd->work); } - - mutex_unlock(&vq->mutex); - return; - -err_free: - vhost_scsi_free_cmd(cmd); -err_cmd: - vhost_scsi_send_bad_target(vs, vq, head, out); out: mutex_unlock(&vq->mutex); } -- 2.20.1