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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/target/target_core_cdb.c b/drivers/target/target_core_cdb.c
index 94d89f2b97d2a7374a5340a6613fd329b8f760e1..52a5f6208acf461896e9e08ea71e927c6e8de46d 100644 (file)
--- a/drivers/target/target_core_cdb.c
+++ b/drivers/target/target_core_cdb.c
@@ -1041,6 +1041,11 @@ 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];