From: David Disseldorp Date: Tue, 19 Jun 2018 15:58:24 +0000 (+0200) Subject: scsi: target: Fix truncated PR-in ReadKeys response X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=63ce3c384db26494615e3c8972bcd419ed71f4c4;p=linux.git scsi: 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. According to Maged: Yes it fixes the "Storage Spaces Persistent Reservation" test in the Windows 2016 Server Failover Cluster validation suites when having many connections that result in more than 8 registrations. I tested your patch on 4.17 with iblock. This behaviour can be tested using the libiscsi PrinReadKeys.Truncate test. Cc: stable@vger.kernel.org Signed-off-by: David Disseldorp Reviewed-by: Mike Christie Tested-by: Maged Mokhtar Reviewed-by: Christoph Hellwig Signed-off-by: Martin K. Petersen --- diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c index 01ac306131c1f..10db5656fd5dc 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);