Commit 984a9d4c authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

Revert "target: Fix VERIFY and WRITE VERIFY command parsing" 



This reverts commit 0e2eb7d1

  Author: Bart Van Assche <bart.vanassche@sandisk.com>
  Date:   Thu Mar 30 10:12:39 2017 -0700

      target: Fix VERIFY and WRITE VERIFY command parsing

This patch broke existing behaviour for WRITE_VERIFY because
it dropped the original SCF_SCSI_DATA_CDB assignment for
bytchk = 0 so target_cmd_size_check() no longer rejected
this case, allowing an overflow case to trigger an OOPs
in iscsi-target.

Since the short term and long term fixes are still being
discussed, revert it for now since it's late in the merge
window and try again in v4.13-rc1.

Conflicts:
	drivers/target/target_core_sbc.c

Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent bd2c52d7

drivers/target/target_core_sbc.c

+10 −64
Original line number Diff line number Diff line
@@ -831,60 +831,6 @@ sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb) 
	return 0;

}



/**

 * sbc_parse_verify - parse VERIFY, VERIFY_16 and WRITE VERIFY commands

 * @cmd:     (in)  structure that describes the SCSI command to be parsed.

 * @sectors: (out) Number of logical blocks on the storage medium that will be

 *           affected by the SCSI command.

 * @bufflen: (out) Expected length of the SCSI Data-Out buffer.

 */

static sense_reason_t sbc_parse_verify(struct se_cmd *cmd, int *sectors,

				       u32 *bufflen)

{

	struct se_device *dev = cmd->se_dev;

	u8 *cdb = cmd->t_task_cdb;

	u8 bytchk = (cdb[1] >> 1) & 3;

	sense_reason_t ret;



	switch (cdb[0]) {

	case VERIFY:

	case WRITE_VERIFY:

		*sectors = transport_get_sectors_10(cdb);

		cmd->t_task_lba = transport_lba_32(cdb);

		break;

	case VERIFY_16:

	case WRITE_VERIFY_16:

		*sectors = transport_get_sectors_16(cdb);

		cmd->t_task_lba = transport_lba_64(cdb);

		break;

	default:

		WARN_ON_ONCE(true);

		return TCM_UNSUPPORTED_SCSI_OPCODE;

	}



	if (sbc_check_dpofua(dev, cmd, cdb))

		return TCM_INVALID_CDB_FIELD;



	ret = sbc_check_prot(dev, cmd, cdb, *sectors, true);

	if (ret)

		return ret;



	switch (bytchk) {

	case 0:

		*bufflen = 0;

		break;

	case 1:

		*bufflen = sbc_get_size(cmd, *sectors);

		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;

		break;

	default:

		pr_err("Unsupported BYTCHK value %d for SCSI opcode %#x\n",

		       bytchk, cdb[0]);

		return TCM_INVALID_CDB_FIELD;

	}

	return TCM_NO_SENSE;

}



sense_reason_t

sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)

{
@@ -952,6 +898,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		cmd->execute_cmd = sbc_execute_rw;

		break;

	case WRITE_10:

	case WRITE_VERIFY:

		sectors = transport_get_sectors_10(cdb);

		cmd->t_task_lba = transport_lba_32(cdb);
@@ -965,13 +912,6 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;

		cmd->execute_cmd = sbc_execute_rw;

		break;

	case WRITE_VERIFY:

	case WRITE_VERIFY_16:

		ret = sbc_parse_verify(cmd, &sectors, &size);

		if (ret)

			return ret;

		cmd->execute_cmd = sbc_execute_rw;

		goto check_lba;

	case WRITE_12:

		sectors = transport_get_sectors_12(cdb);

		cmd->t_task_lba = transport_lba_32(cdb);
@@ -987,6 +927,7 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		cmd->execute_cmd = sbc_execute_rw;

		break;

	case WRITE_16:

	case WRITE_VERIFY_16:

		sectors = transport_get_sectors_16(cdb);

		cmd->t_task_lba = transport_lba_64(cdb);
@@ -1169,9 +1110,14 @@ sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops) 
		break;

	case VERIFY:

	case VERIFY_16:

		ret = sbc_parse_verify(cmd, &sectors, &size);

		if (ret)

			return ret;

		size = 0;

		if (cdb[0] == VERIFY) {

			sectors = transport_get_sectors_10(cdb);

			cmd->t_task_lba = transport_lba_32(cdb);

		} else {

			sectors = transport_get_sectors_16(cdb);

			cmd->t_task_lba = transport_lba_64(cdb);

		}

		cmd->execute_cmd = sbc_emulate_noop;

		goto check_lba;

	case REZERO_UNIT:

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