On 09.02.21 08:22, Aleksandr Miloserdov wrote:
TCM buffer length doesn't necessarily equal 8 + ADDITIONAL LENGTH which
might be considered an underflow in case of Data-In size being greater than
8 + ADDITIONAL LENGTH. So truncate buffer length to prevent underflow.
Signed-off-by: Aleksandr Miloserdov <a.miloserdov@xxxxxxxxx>
Reviewed-by: Roman Bolshakov <r.bolshakov@xxxxxxxxx>
---
drivers/target/target_core_pr.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
index 14db5e568f22..a13140e95b47 100644
--- a/drivers/target/target_core_pr.c
+++ b/drivers/target/target_core_pr.c
@@ -3739,6 +3739,7 @@ core_scsi3_pri_read_keys(struct se_cmd *cmd)
spin_unlock(&dev->t10_pr.registration_lock);
put_unaligned_be32(add_len, &buf[4]);
+ target_set_cmd_data_length(cmd, 8 + add_len);
transport_kunmap_data_sg(cmd);
@@ -3757,7 +3758,7 @@ core_scsi3_pri_read_reservation(struct se_cmd *cmd)
struct t10_pr_registration *pr_reg;
unsigned char *buf;
u64 pr_res_key;
- u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
+ u32 add_len = 0;
if (cmd->data_length < 8) {
pr_err("PRIN SA READ_RESERVATIONS SCSI Data Length: %u"
@@ -3775,8 +3776,9 @@ core_scsi3_pri_read_reservation(struct se_cmd *cmd)
pr_reg = dev->dev_pr_res_holder;
if (pr_reg) {
/*
- * Set the hardcoded Additional Length
+ * Set the Additional Length to 16 when a reservation is held
*/
+ add_len = 16;
put_unaligned_be32(add_len, &buf[4]);
if (cmd->data_length < 22)
@@ -3812,6 +3814,8 @@ core_scsi3_pri_read_reservation(struct se_cmd *cmd)
(pr_reg->pr_res_type & 0x0f);
}
+ target_set_cmd_data_length(cmd, 8 + add_len);
+
err:
spin_unlock(&dev->dev_reservation_lock);
transport_kunmap_data_sg(cmd);
@@ -3830,7 +3834,7 @@ core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
struct se_device *dev = cmd->se_dev;
struct t10_reservation *pr_tmpl = &dev->t10_pr;
unsigned char *buf;
- u16 add_len = 8; /* Hardcoded to 8. */
+ u16 len = 8; /* Hardcoded to 8. */
if (cmd->data_length < 6) {
pr_err("PRIN SA REPORT_CAPABILITIES SCSI Data Length:"
@@ -3842,7 +3846,7 @@ core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
if (!buf)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
- put_unaligned_be16(add_len, &buf[0]);
+ put_unaligned_be16(len, &buf[0]);
buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
@@ -3871,6 +3875,8 @@ core_scsi3_pri_report_capabilities(struct se_cmd *cmd)
buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
+ target_set_cmd_data_length(cmd, len);
+
transport_kunmap_data_sg(cmd);
return 0;
@@ -4031,6 +4037,7 @@ core_scsi3_pri_read_full_status(struct se_cmd *cmd)
* Set ADDITIONAL_LENGTH
*/
put_unaligned_be32(add_len, &buf[4]);
+ target_set_cmd_data_length(cmd, 8 + add_len);
transport_kunmap_data_sg(cmd);
Looks ok to me.
Reviewed-by: Bodo Stroesser <bostroesser@xxxxxxxxx>
