4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
commit 4ff83daa0200affe1894bd33d17bac404e3d78d4 upstream.
During v4.3 when the overflow/underflow check was relaxed by
commit c72c525022:
commit c72c5250224d475614a00c1d7e54a67f77cd3410
Author: Roland Dreier <roland@xxxxxxxxxxxxxxx>
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@xxxxxxxxxxx>
Cc: Roland Dreier <roland@xxxxxxxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1182,15 +1182,28 @@ target_cmd_size_check(struct se_cmd *cmd
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