target: Check number of unmap descriptors against our limit

commit 7409a6657aebf8be74c21d0eded80709b27275cb upstream.

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

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
[bwh: Backported to 3.2: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/target/target_core_cdb.c b/drivers/target/target_core_cdb.c
index 00f0f7d..717a8d4 100644 (file)
--- a/drivers/target/target_core_cdb.c
+++ b/drivers/target/target_core_cdb.c
@@ -1133,6 +1133,11 @@ int target_emulate_unmap(struct se_task *task)
        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];