From: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
This patch changes transport_generic_map_mem_to_cmd() to reject SCSI data
overflow and to send exception status with CHECK_CONDITION + TCM_INVALID_CDB_FIELD
for fabrics that are passing a pre-populated struct scatterlist (eg: tcm_loop
and iscsi-target) being mapped into se_cmd->t_data_sg and se_cmd->t_data_nents.
This addresses an OOPs where transport_allocate_data_tasks() would walk
the incorrect post OVERFLOW cmd->data_length value beyond the end of
the passed scatterlist.
Cc: <lists@xxxxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Andy Grover <agrover@xxxxxxxxxx>
Signed-off-by: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
---
drivers/target/target_core_transport.c | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 981dfa9..b9e8161 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -3436,6 +3436,18 @@ int transport_generic_map_mem_to_cmd(
if ((cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) ||
(cmd->se_cmd_flags & SCF_SCSI_CONTROL_SG_IO_CDB)) {
+ /*
+ * Reject SCSI data overflow with map_mem_to_cmd() as incoming
+ * scatterlists already have been set to follow what the fabric
+ * passes for the original expected data transfer length.
+ */
+ if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
+ pr_warn("Rejecting SCSI DATA overflow for fabric using"
+ " SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
+ cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
+ cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
+ return -EINVAL;
+ }
cmd->t_data_sg = sgl;
cmd->t_data_nents = sgl_count;
--
1.7.2.5
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