--------------------------------------------------
From: "David Disseldorp" <ddiss@xxxxxxx>
Sent: Friday, June 01, 2018 1:20 AM
To: <target-devel@xxxxxxxxxxxxxxx>
Cc: "ronnie sahlberg" <ronniesahlberg@xxxxxxxxx>; "David Disseldorp"
<ddiss@xxxxxxx>
Subject: [PATCH] target: fix truncated PR-in ReadKeys response
SPC5r17 states that the contents of the ADDITIONAL LENGTH field are not
altered based on the allocation length, so always calculate and pack the
full key list length even if the list itself is truncated.
This behaviour can be tested using the libiscsi PrinReadKeys.Truncate
test.
Signed-off-by: David Disseldorp <ddiss@xxxxxxx>
---
drivers/target/target_core_pr.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)
diff --git a/drivers/target/target_core_pr.c
b/drivers/target/target_core_pr.c
index 01ac306131c1..2e865fdaa362 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -3727,11 +3727,16 @@ core_scsi3_pri_read_keys(struct se_cmd *cmd)
* Check for overflow of 8byte PRI READ_KEYS payload and
* next reservation key list descriptor.
*/
- if ((add_len + 8) > (cmd->data_length - 8))
- break;
-
- put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
- off += 8;
+ if ((off + 8) <= cmd->data_length) {
+ put_unaligned_be64(pr_reg->pr_res_key, &buf[off]);
+ off += 8;
+ }
+ /*
+ * SPC5r17: 6.16.2 READ KEYS service action
+ * The ADDITIONAL LENGTH field indicates the number of bytes in
+ * the Reservation key list. The contents of the ADDITIONAL
+ * LENGTH field are not altered based on the allocation length
+ */
add_len += 8;
}
spin_unlock(&dev->t10_pr.registration_lock);
--
2.13.6
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This also fixes an issue in Windows server 2016 failover cluster with
many client connections, the initial allocation length sent in cdb is
72 bytes which limits it to 8 keys, with additional length not affected
by truncation, it will retry with correct size.
Interesting I was looking at the same issue in target_core_rbd.
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