Commit message: scsi: aacraid: Don't copy uninitialized stack memory to userspace

Both aac_send_raw_srb() and aac_get_hba_info() may copy stack allocated
structs to userspace without initializing all members of these
structs. Clear out this memory to prevent information leaks.

Fixes: 423400e64d377 ("scsi: aacraid: Include HBA direct interface")
Fixes: c799d519bf088 ("scsi: aacraid: Retrieve HBA host information ioctl")
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
CVE: CVE-2017-18549
CWE: CWE-200
Vulnerability description: An issue was discovered in drivers/scsi/aacraid/commctrl.c in the Linux kernel before 4.13. There is potential exposure of kernel stack memory because aac_send_raw_srb does not initialize the reply structure.

Project: linux
File: commctrl.c

static int aac_send_raw_srb(struct aac_dev* dev, void __user * arg)
{
	struct fib* srbfib;
	int status;
	struct aac_srb *srbcmd = NULL;
	struct aac_hba_cmd_req *hbacmd = NULL;
	struct user_aac_srb *user_srbcmd = NULL;
	struct user_aac_srb __user *user_srb = arg;
	struct aac_srb_reply __user *user_reply;
	u32 chn;
	u32 fibsize = 0;
	u32 flags = 0;
	s32 rcode = 0;
	u32 data_dir;
	void __user *sg_user[HBA_MAX_SG_EMBEDDED];
	void *sg_list[HBA_MAX_SG_EMBEDDED];
	u32 sg_count[HBA_MAX_SG_EMBEDDED];
	u32 sg_indx = 0;
	u32 byte_count = 0;
	u32 actual_fibsize64, actual_fibsize = 0;
	int i;
	int is_native_device;
	u64 address;


	if (dev->in_reset) {
		dprintk((KERN_DEBUG"aacraid: send raw srb -EBUSY\n"));
		return -EBUSY;
	}
	if (!capable(CAP_SYS_ADMIN)){
		dprintk((KERN_DEBUG"aacraid: No permission to send raw srb\n"));
		return -EPERM;
	}
	/*
	 *	Allocate and initialize a Fib then setup a SRB command
	 */
	if (!(srbfib = aac_fib_alloc(dev))) {
		return -ENOMEM;
	}

	memset(sg_list, 0, sizeof(sg_list)); /* cleanup may take issue */
	if(copy_from_user(&fibsize, &user_srb->count,sizeof(u32))){
		dprintk((KERN_DEBUG"aacraid: Could not copy data size from user\n"));
		rcode = -EFAULT;
		goto cleanup;
	}

	if ((fibsize < (sizeof(struct user_aac_srb) - sizeof(struct user_sgentry))) ||
	    (fibsize > (dev->max_fib_size - sizeof(struct aac_fibhdr)))) {
		rcode = -EINVAL;
		goto cleanup;
	}

	user_srbcmd = kmalloc(fibsize, GFP_KERNEL);
	if (!user_srbcmd) {
		dprintk((KERN_DEBUG"aacraid: Could not make a copy of the srb\n"));
		rcode = -ENOMEM;
		goto cleanup;
	}
	if(copy_from_user(user_srbcmd, user_srb,fibsize)){
		dprintk((KERN_DEBUG"aacraid: Could not copy srb from user\n"));
		rcode = -EFAULT;
		goto cleanup;
	}

	flags = user_srbcmd->flags; /* from user in cpu order */
	switch (flags & (SRB_DataIn | SRB_DataOut)) {
	case SRB_DataOut:
		data_dir = DMA_TO_DEVICE;
		break;
	case (SRB_DataIn | SRB_DataOut):
		data_dir = DMA_BIDIRECTIONAL;
		break;
	case SRB_DataIn:
		data_dir = DMA_FROM_DEVICE;
		break;
	default:
		data_dir = DMA_NONE;
	}
	if (user_srbcmd->sg.count > ARRAY_SIZE(sg_list)) {
		dprintk((KERN_DEBUG"aacraid: too many sg entries %d\n",
			user_srbcmd->sg.count));
		rcode = -EINVAL;
		goto cleanup;
	}
	if ((data_dir == DMA_NONE) && user_srbcmd->sg.count) {
		dprintk((KERN_DEBUG"aacraid:SG with no direction specified\n"));
		rcode = -EINVAL;
		goto cleanup;
	}
	actual_fibsize = sizeof(struct aac_srb) - sizeof(struct sgentry) +
		((user_srbcmd->sg.count & 0xff) * sizeof(struct sgentry));
	actual_fibsize64 = actual_fibsize + (user_srbcmd->sg.count & 0xff) *
	  (sizeof(struct sgentry64) - sizeof(struct sgentry));
	/* User made a mistake - should not continue */
	if ((actual_fibsize != fibsize) && (actual_fibsize64 != fibsize)) {
		dprintk((KERN_DEBUG"aacraid: Bad Size specified in "
		  "Raw SRB command calculated fibsize=%lu;%lu "
		  "user_srbcmd->sg.count=%d aac_srb=%lu sgentry=%lu;%lu "
		  "issued fibsize=%d\n",
		  actual_fibsize, actual_fibsize64, user_srbcmd->sg.count,
		  sizeof(struct aac_srb), sizeof(struct sgentry),
		  sizeof(struct sgentry64), fibsize));
		rcode = -EINVAL;
		goto cleanup;
	}

	chn = user_srbcmd->channel;
	if (chn < AAC_MAX_BUSES && user_srbcmd->id < AAC_MAX_TARGETS &&
		dev->hba_map[chn][user_srbcmd->id].devtype ==
		AAC_DEVTYPE_NATIVE_RAW) {
		is_native_device = 1;
		hbacmd = (struct aac_hba_cmd_req *)srbfib->hw_fib_va;
		memset(hbacmd, 0, 96);	/* sizeof(*hbacmd) is not necessary */

		/* iu_type is a parameter of aac_hba_send */
		switch (data_dir) {
		case DMA_TO_DEVICE:
			hbacmd->byte1 = 2;
			break;
		case DMA_FROM_DEVICE:
		case DMA_BIDIRECTIONAL:
			hbacmd->byte1 = 1;
			break;
		case DMA_NONE:
		default:
			break;
		}
		hbacmd->lun[1] = cpu_to_le32(user_srbcmd->lun);
		hbacmd->it_nexus = dev->hba_map[chn][user_srbcmd->id].rmw_nexus;

		/*
		 * we fill in reply_qid later in aac_src_deliver_message
		 * we fill in iu_type, request_id later in aac_hba_send
		 * we fill in emb_data_desc_count, data_length later
		 * in sg list build
		 */

		memcpy(hbacmd->cdb, user_srbcmd->cdb, sizeof(hbacmd->cdb));

		address = (u64)srbfib->hw_error_pa;
		hbacmd->error_ptr_hi = cpu_to_le32((u32)(address >> 32));
		hbacmd->error_ptr_lo = cpu_to_le32((u32)(address & 0xffffffff));
		hbacmd->error_length = cpu_to_le32(FW_ERROR_BUFFER_SIZE);
		hbacmd->emb_data_desc_count =
					cpu_to_le32(user_srbcmd->sg.count);
		srbfib->hbacmd_size = 64 +
			user_srbcmd->sg.count * sizeof(struct aac_hba_sgl);

	} else {
		is_native_device = 0;
		aac_fib_init(srbfib);

		/* raw_srb FIB is not FastResponseCapable */
		srbfib->hw_fib_va->header.XferState &=
			~cpu_to_le32(FastResponseCapable);

		srbcmd = (struct aac_srb *) fib_data(srbfib);

		// Fix up srb for endian and force some values

		srbcmd->function = cpu_to_le32(SRBF_ExecuteScsi); // Force this
		srbcmd->channel	 = cpu_to_le32(user_srbcmd->channel);
		srbcmd->id	 = cpu_to_le32(user_srbcmd->id);
		srbcmd->lun	 = cpu_to_le32(user_srbcmd->lun);
		srbcmd->timeout	 = cpu_to_le32(user_srbcmd->timeout);
		srbcmd->flags	 = cpu_to_le32(flags);
		srbcmd->retry_limit = 0; // Obsolete parameter
		srbcmd->cdb_size = cpu_to_le32(user_srbcmd->cdb_size);
		memcpy(srbcmd->cdb, user_srbcmd->cdb, sizeof(srbcmd->cdb));
	}

	byte_count = 0;
	if (is_native_device) {
		struct user_sgmap *usg32 = &user_srbcmd->sg;
		struct user_sgmap64 *usg64 =
			(struct user_sgmap64 *)&user_srbcmd->sg;

		for (i = 0; i < usg32->count; i++) {
			void *p;
			u64 addr;

			sg_count[i] = (actual_fibsize64 == fibsize) ?
				usg64->sg[i].count : usg32->sg[i].count;
			if (sg_count[i] >
				(dev->scsi_host_ptr->max_sectors << 9)) {
				pr_err("aacraid: upsg->sg[%d].count=%u>%u\n",
					i, sg_count[i],
					dev->scsi_host_ptr->max_sectors << 9);
				rcode = -EINVAL;
				goto cleanup;
			}

			p = kmalloc(sg_count[i], GFP_KERNEL);
			if (!p) {
				rcode = -ENOMEM;
				goto cleanup;
			}

			if (actual_fibsize64 == fibsize) {
				addr = (u64)usg64->sg[i].addr[0];
				addr += ((u64)usg64->sg[i].addr[1]) << 32;
			} else {
				addr = (u64)usg32->sg[i].addr;
			}

			sg_user[i] = (void __user *)(uintptr_t)addr;
			sg_list[i] = p; // save so we can clean up later
			sg_indx = i;

			if (flags & SRB_DataOut) {
				if (copy_from_user(p, sg_user[i],
					sg_count[i])) {
					rcode = -EFAULT;
					goto cleanup;
				}
			}
			addr = pci_map_single(dev->pdev, p, sg_count[i],
						data_dir);
			hbacmd->sge[i].addr_hi = cpu_to_le32((u32)(addr>>32));
			hbacmd->sge[i].addr_lo = cpu_to_le32(
						(u32)(addr & 0xffffffff));
			hbacmd->sge[i].len = cpu_to_le32(sg_count[i]);
			hbacmd->sge[i].flags = 0;
			byte_count += sg_count[i];
		}

		if (usg32->count > 0)	/* embedded sglist */
			hbacmd->sge[usg32->count-1].flags =
				cpu_to_le32(0x40000000);
		hbacmd->data_length = cpu_to_le32(byte_count);

		status = aac_hba_send(HBA_IU_TYPE_SCSI_CMD_REQ, srbfib,
					NULL, NULL);

	} else if (dev->adapter_info.options & AAC_OPT_SGMAP_HOST64) {
		struct user_sgmap64* upsg = (struct user_sgmap64*)&user_srbcmd->sg;
		struct sgmap64* psg = (struct sgmap64*)&srbcmd->sg;

		/*
		 * This should also catch if user used the 32 bit sgmap
		 */
		if (actual_fibsize64 == fibsize) {
			actual_fibsize = actual_fibsize64;
			for (i = 0; i < upsg->count; i++) {
				u64 addr;
				void* p;

				sg_count[i] = upsg->sg[i].count;
				if (sg_count[i] >
				    ((dev->adapter_info.options &
				     AAC_OPT_NEW_COMM) ?
				      (dev->scsi_host_ptr->max_sectors << 9) :
				      65536)) {
					rcode = -EINVAL;
					goto cleanup;
				}

				p = kmalloc(sg_count[i], GFP_KERNEL);
				if(!p) {
					dprintk((KERN_DEBUG"aacraid: Could not allocate SG buffer - size = %d buffer number %d of %d\n",
					  sg_count[i], i, upsg->count));
					rcode = -ENOMEM;
					goto cleanup;
				}
				addr = (u64)upsg->sg[i].addr[0];
				addr += ((u64)upsg->sg[i].addr[1]) << 32;
				sg_user[i] = (void __user *)(uintptr_t)addr;
				sg_list[i] = p; // save so we can clean up later
				sg_indx = i;

				if (flags & SRB_DataOut) {
					if (copy_from_user(p, sg_user[i],
						sg_count[i])){
						dprintk((KERN_DEBUG"aacraid: Could not copy sg data from user\n"));
						rcode = -EFAULT;
						goto cleanup;
					}
				}
				addr = pci_map_single(dev->pdev, p,
							sg_count[i], data_dir);

				psg->sg[i].addr[0] = cpu_to_le32(addr & 0xffffffff);
				psg->sg[i].addr[1] = cpu_to_le32(addr>>32);
				byte_count += sg_count[i];
				psg->sg[i].count = cpu_to_le32(sg_count[i]);
			}
		} else {
			struct user_sgmap* usg;
			usg = kmemdup(upsg,
				      actual_fibsize - sizeof(struct aac_srb)
				      + sizeof(struct sgmap), GFP_KERNEL);
			if (!usg) {
				dprintk((KERN_DEBUG"aacraid: Allocation error in Raw SRB command\n"));
				rcode = -ENOMEM;
				goto cleanup;
			}
			actual_fibsize = actual_fibsize64;

			for (i = 0; i < usg->count; i++) {
				u64 addr;
				void* p;

				sg_count[i] = usg->sg[i].count;
				if (sg_count[i] >
				    ((dev->adapter_info.options &
				     AAC_OPT_NEW_COMM) ?
				      (dev->scsi_host_ptr->max_sectors << 9) :
				      65536)) {
					kfree(usg);
					rcode = -EINVAL;
					goto cleanup;
				}

				p = kmalloc(sg_count[i], GFP_KERNEL);
				if(!p) {
					dprintk((KERN_DEBUG "aacraid: Could not allocate SG buffer - size = %d buffer number %d of %d\n",
						sg_count[i], i, usg->count));
					kfree(usg);
					rcode = -ENOMEM;
					goto cleanup;
				}
				sg_user[i] = (void __user *)(uintptr_t)usg->sg[i].addr;
				sg_list[i] = p; // save so we can clean up later
				sg_indx = i;

				if (flags & SRB_DataOut) {
					if (copy_from_user(p, sg_user[i],
						sg_count[i])) {
						kfree (usg);
						dprintk((KERN_DEBUG"aacraid: Could not copy sg data from user\n"));
						rcode = -EFAULT;
						goto cleanup;
					}
				}
				addr = pci_map_single(dev->pdev, p,
							sg_count[i], data_dir);

				psg->sg[i].addr[0] = cpu_to_le32(addr & 0xffffffff);
				psg->sg[i].addr[1] = cpu_to_le32(addr>>32);
				byte_count += sg_count[i];
				psg->sg[i].count = cpu_to_le32(sg_count[i]);
			}
			kfree (usg);
		}
		srbcmd->count = cpu_to_le32(byte_count);
		if (user_srbcmd->sg.count)
			psg->count = cpu_to_le32(sg_indx+1);
		else
			psg->count = 0;
		status = aac_fib_send(ScsiPortCommand64, srbfib, actual_fibsize, FsaNormal, 1, 1,NULL,NULL);
	} else {
		struct user_sgmap* upsg = &user_srbcmd->sg;
		struct sgmap* psg = &srbcmd->sg;

		if (actual_fibsize64 == fibsize) {
			struct user_sgmap64* usg = (struct user_sgmap64 *)upsg;
			for (i = 0; i < upsg->count; i++) {
				uintptr_t addr;
				void* p;

				sg_count[i] = usg->sg[i].count;
				if (sg_count[i] >
				    ((dev->adapter_info.options &
				     AAC_OPT_NEW_COMM) ?
				      (dev->scsi_host_ptr->max_sectors << 9) :
				      65536)) {
					rcode = -EINVAL;
					goto cleanup;
				}
				p = kmalloc(sg_count[i], GFP_KERNEL|GFP_DMA32);
				if (!p) {
					dprintk((KERN_DEBUG"aacraid: Could not allocate SG buffer - size = %d buffer number %d of %d\n",
						sg_count[i], i, usg->count));
					rcode = -ENOMEM;
					goto cleanup;
				}
				addr = (u64)usg->sg[i].addr[0];
				addr += ((u64)usg->sg[i].addr[1]) << 32;
				sg_user[i] = (void __user *)addr;
				sg_list[i] = p; // save so we can clean up later
				sg_indx = i;

				if (flags & SRB_DataOut) {
					if (copy_from_user(p, sg_user[i],
						sg_count[i])){
						dprintk((KERN_DEBUG"aacraid: Could not copy sg data from user\n"));
						rcode = -EFAULT;
						goto cleanup;
					}
				}
				addr = pci_map_single(dev->pdev, p, usg->sg[i].count, data_dir);

				psg->sg[i].addr = cpu_to_le32(addr & 0xffffffff);
				byte_count += usg->sg[i].count;
				psg->sg[i].count = cpu_to_le32(sg_count[i]);
			}
		} else {
			for (i = 0; i < upsg->count; i++) {
				dma_addr_t addr;
				void* p;

				sg_count[i] = upsg->sg[i].count;
				if (sg_count[i] >
				    ((dev->adapter_info.options &
				     AAC_OPT_NEW_COMM) ?
				      (dev->scsi_host_ptr->max_sectors << 9) :
				      65536)) {
					rcode = -EINVAL;
					goto cleanup;
				}
				p = kmalloc(sg_count[i], GFP_KERNEL|GFP_DMA32);
				if (!p) {
					dprintk((KERN_DEBUG"aacraid: Could not allocate SG buffer - size = %d buffer number %d of %d\n",
					  sg_count[i], i, upsg->count));
					rcode = -ENOMEM;
					goto cleanup;
				}
				sg_user[i] = (void __user *)(uintptr_t)upsg->sg[i].addr;
				sg_list[i] = p; // save so we can clean up later
				sg_indx = i;

				if (flags & SRB_DataOut) {
					if (copy_from_user(p, sg_user[i],
						sg_count[i])) {
						dprintk((KERN_DEBUG"aacraid: Could not copy sg data from user\n"));
						rcode = -EFAULT;
						goto cleanup;
					}
				}
				addr = pci_map_single(dev->pdev, p,
					sg_count[i], data_dir);

				psg->sg[i].addr = cpu_to_le32(addr);
				byte_count += sg_count[i];
				psg->sg[i].count = cpu_to_le32(sg_count[i]);
			}
		}
		srbcmd->count = cpu_to_le32(byte_count);
		if (user_srbcmd->sg.count)
			psg->count = cpu_to_le32(sg_indx+1);
		else
			psg->count = 0;
		status = aac_fib_send(ScsiPortCommand, srbfib, actual_fibsize, FsaNormal, 1, 1, NULL, NULL);
	}

	if (status == -ERESTARTSYS) {
		rcode = -ERESTARTSYS;
		goto cleanup;
	}

	if (status != 0) {
		dprintk((KERN_DEBUG"aacraid: Could not send raw srb fib to hba\n"));
		rcode = -ENXIO;
		goto cleanup;
	}

	if (flags & SRB_DataIn) {
		for(i = 0 ; i <= sg_indx; i++){
			if (copy_to_user(sg_user[i], sg_list[i], sg_count[i])) {
				dprintk((KERN_DEBUG"aacraid: Could not copy sg data to user\n"));
				rcode = -EFAULT;
				goto cleanup;

			}
		}
	}

	user_reply = arg + fibsize;
	if (is_native_device) {
		struct aac_hba_resp *err =
			&((struct aac_native_hba *)srbfib->hw_fib_va)->resp.err;
		struct aac_srb_reply reply;

		reply.status = ST_OK;
		if (srbfib->flags & FIB_CONTEXT_FLAG_FASTRESP) {
			/* fast response */
			reply.srb_status = SRB_STATUS_SUCCESS;
			reply.scsi_status = 0;
			reply.data_xfer_length = byte_count;
			reply.sense_data_size = 0;
			memset(reply.sense_data, 0, AAC_SENSE_BUFFERSIZE);
		} else {
			reply.srb_status = err->service_response;
			reply.scsi_status = err->status;
			reply.data_xfer_length = byte_count -
				le32_to_cpu(err->residual_count);
			reply.sense_data_size = err->sense_response_data_len;
			memcpy(reply.sense_data, err->sense_response_buf,
				AAC_SENSE_BUFFERSIZE);
		}
		if (copy_to_user(user_reply, &reply,
			sizeof(struct aac_srb_reply))) {
			dprintk((KERN_DEBUG"aacraid: Copy to user failed\n"));
			rcode = -EFAULT;
			goto cleanup;
		}
	} else {
		struct aac_srb_reply *reply;

		reply = (struct aac_srb_reply *) fib_data(srbfib);
		if (copy_to_user(user_reply, reply,
			sizeof(struct aac_srb_reply))) {
			dprintk((KERN_DEBUG"aacraid: Copy to user failed\n"));
			rcode = -EFAULT;
			goto cleanup;
		}
	}

cleanup:
	kfree(user_srbcmd);
	if (rcode != -ERESTARTSYS) {
		for (i = 0; i <= sg_indx; i++)
			kfree(sg_list[i]);
		aac_fib_complete(srbfib);
		aac_fib_free(srbfib);
	}

	return rcode;
}