From: Aleksandr Miloserdov <a.miloserdov@xxxxxxxxx> [ Upstream commit 14d24e2cc77411301e906a8cf41884739de192de ] 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. Link: https://lore.kernel.org/r/20210209072202.41154-3-a.miloserdov@xxxxxxxxx Reviewed-by: Roman Bolshakov <r.bolshakov@xxxxxxxxx> Reviewed-by: Bodo Stroesser <bostroesser@xxxxxxxxx> Signed-off-by: Aleksandr Miloserdov <a.miloserdov@xxxxxxxxx> Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 10db5656fd5d..949879f2f1d1 100644 --- a/drivers/target/target_core_pr.c +++ b/drivers/target/target_core_pr.c @@ -3742,6 +3742,7 @@ 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); @@ -3760,7 +3761,7 @@ 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" @@ -3778,8 +3779,9 @@ 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) @@ -3815,6 +3817,8 @@ 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); @@ -3833,7 +3837,7 @@ 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:" @@ -3845,7 +3849,7 @@ 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 */ @@ -3874,6 +3878,8 @@ 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; @@ -4034,6 +4040,7 @@ 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); -- 2.30.1
