NULL pointer dereference happens when a SCSI command is received for a
non-existing LU and tracing is enabled. The following call sequences
lead to NULL pointer dereference:
1) iscsit_setup_scsi_cmd
transport_lookup_cmd_lun <-- lookup fails.
iscsit_process_scsi_cmd
iscsit_sequence_cmd
transport_send_check_condition_and_sense
trace_target_cmd_complete <-- NULL dereference
2) target_submit_cmd_map_sgls
transport_lookup_cmd_lun <-- lookup fails
transport_send_check_condition_and_sense
trace_target_cmd_complete <-- NULL dereference
In the above sequence, cmd->t_task_cdb is uninitialized which when
referenced in trace_target_cmd_complete() causes NULL pointer dereference.
The fix is to use the helper, target_init_cmd_from_cdb() and call it
before transport_lookup_cmd_lun() is called, so that cmd->t_task_cdb can
be initialized and hence can be referenced in
trace_target_cmd_complete().
Signed-off-by: Sudhakar Panneerselvam <sudhakar.panneerselvam@xxxxxxxxxx>
---
drivers/target/iscsi/iscsi_target.c | 19 ++++++++++++-------
drivers/target/target_core_transport.c | 11 +++++++++--
drivers/target/target_core_xcopy.c | 3 +++
3 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
index 59379d662626..a90b80aee9d8 100644
--- a/drivers/target/iscsi/iscsi_target.c
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -1167,6 +1167,17 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
target_get_sess_cmd(&cmd->se_cmd, true);
+ cmd->se_cmd.orig_fe_lun = scsilun_to_int(&hdr->lun);
+ cmd->sense_reason = target_init_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
+ if (cmd->sense_reason) {
+ if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
+ return iscsit_add_reject_cmd(cmd,
+ ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
+ }
+
+ goto attach_cmd;
+ }
+
cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd,
scsilun_to_int(&hdr->lun));
if (cmd->sense_reason)
@@ -1175,14 +1186,8 @@ int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
/* only used for printks or comparing with ->ref_task_tag */
cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
- if (cmd->sense_reason) {
- if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
- return iscsit_add_reject_cmd(cmd,
- ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
- }
-
+ if (cmd->sense_reason)
goto attach_cmd;
- }
if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
return iscsit_add_reject_cmd(cmd,
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index f93e25baa664..2e878188dff7 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1455,8 +1455,6 @@ void transport_init_se_cmd(
struct se_device *dev = cmd->se_dev;
sense_reason_t ret;
- target_init_cmd_from_cdb(cmd, cdb);
-
ret = dev->transport->parse_cdb(cmd);
if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
@@ -1619,6 +1617,15 @@ int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess
*/
if (flags & TARGET_SCF_BIDI_OP)
se_cmd->se_cmd_flags |= SCF_BIDI;
+
+ se_cmd->orig_fe_lun = unpacked_lun;
+ rc = target_init_cmd_from_cdb(se_cmd, cdb);
+ if (rc) {
+ transport_send_check_condition_and_sense(se_cmd, rc, 0);
+ target_put_sess_cmd(se_cmd);
+ return 0;
+ }
+
/*
* Locate se_lun pointer and attach it to struct se_cmd
*/
diff --git a/drivers/target/target_core_xcopy.c b/drivers/target/target_core_xcopy.c
index bd3ed6ce7571..b20c25343cf1 100644
--- a/drivers/target/target_core_xcopy.c
+++ b/drivers/target/target_core_xcopy.c
@@ -526,6 +526,9 @@ static int target_xcopy_setup_pt_cmd(
}
cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
+ if (target_init_cmd_from_cdb(cmd, cdb))
+ return -EINVAL;
+
cmd->tag = 0;
if (target_setup_cmd_from_cdb(cmd, cdb))
return -EINVAL;
--
1.8.3.1
