From 7409a6657aebf8be74c21d0eded80709b27275cb Mon Sep 17 00:00:00 2001
From: Roland Dreier <roland@purestorage.com>
Date: Mon, 16 Jul 2012 15:34:25 -0700
Subject: target: Check number of unmap descriptors against our limit

Fail UNMAP commands that have more than our reported limit on unmap
descriptors.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Cc: stable@vger.kernel.org
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 2efd70c..76db75e 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -336,6 +336,11 @@ static int iblock_execute_unmap(struct se_cmd *cmd)
 	bd_dl = get_unaligned_be16(&buf[2]);
 
 	size = min(size - 8, bd_dl);
+	if (size / 16 > dev->se_sub_dev->se_dev_attrib.max_unmap_block_desc_count) {
+		cmd->scsi_sense_reason = TCM_INVALID_PARAMETER_LIST;
+		ret = -EINVAL;
+		goto err;
+	}
 
 	/* First UNMAP block descriptor starts at 8 byte offset */
 	ptr = &buf[8];
-- 
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