4.17-stable review patch. If anyone has any objections, please let me know.
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From: David Disseldorp ddiss@suse.de
commit 63ce3c384db26494615e3c8972bcd419ed71f4c4 upstream.
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 ddiss@suse.de Reviewed-by: Mike Christie mchristi@redhat.com Tested-by: Maged Mokhtar mmokhtar@petasan.org Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/target/target_core_pr.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-)
--- 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 * * 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);