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target: Re-add check to reject control WRITEs with overflow data

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During v4.3 when the overflow/underflow check was relaxed by
commit c72c525022:

  commit c72c525022
  Author: Roland Dreier <roland@purestorage.com>
  Date:   Wed Jul 22 15:08:18 2015 -0700

       target: allow underflow/overflow for PR OUT etc. commands

to allow underflow/overflow for Windows compliance + FCP, a
consequence was to allow control CDBs to process overflow
data for iscsi-target with immediate data as well.

As per Roland's original change, continue to allow underflow
cases for control CDBs to make Windows compliance + FCP happy,
but until overflow for control CDBs is supported tree-wide,
explicitly reject all control WRITEs with overflow following
pre v4.3.y logic.

Reported-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Roland Dreier <roland@purestorage.com>
Cc: <stable@vger.kernel.org> # v4.3+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
This commit is contained in:
Nicholas Bellinger 2017-05-11 01:07:24 -07:00
parent 75dbf2d36f
commit 4ff83daa02
1 changed files with 18 additions and 5 deletions
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23
drivers/target/target_core_transport.c
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@ -1160,15 +1160,28 @@ target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
if (cmd->unknown_data_length) {
cmd->data_length = size;
} else if (size != cmd->data_length) {
pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
" %u does not match SCSI CDB Length: %u for SAM Opcode:"
" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
cmd->data_length, size, cmd->t_task_cdb[0]);
if (cmd->data_direction == DMA_TO_DEVICE &&
cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
pr_err("Rejecting underflow/overflow WRITE data\n");
return TCM_INVALID_CDB_FIELD;
if (cmd->data_direction == DMA_TO_DEVICE) {
if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
pr_err_ratelimited("Rejecting underflow/overflow"
" for WRITE data CDB\n");
return TCM_INVALID_CDB_FIELD;
}
/*
* Some fabric drivers like iscsi-target still expect to
* always reject overflow writes. Reject this case until
* full fabric driver level support for overflow writes
* is introduced tree-wide.
*/
if (size > cmd->data_length) {
pr_err_ratelimited("Rejecting overflow for"
" WRITE control CDB\n");
return TCM_INVALID_CDB_FIELD;
}
}
/*
* Reject READ_* or WRITE_* with overflow/underflow for