[PATCH 1/1] hisi_sas: Fix possible buffer overflows in prep_ssp_v3_hw

[Xiaohui Zhang]

From: Zhang Xiaohui <ruc_zhangxiaohui@xxxxxxx>

prep_ssp_v3_hw() calls memcpy() without checking the
destination size may trigger a buffer overflower, which a
local user could use to cause denial of service or the
execution of arbitrary code.
Fix it by putting the length check before calling memcpy().

Signed-off-by: Zhang Xiaohui <ruc_zhangxiaohui@xxxxxxx>
---
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 7133ca859..2664c36d3 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -1267,7 +1267,8 @@ static void prep_ssp_v3_hw(struct hisi_hba *hisi_hba,
 	memcpy(buf_cmd, &task->ssp_task.LUN, 8);
 	if (!tmf) {
 		buf_cmd[9] = ssp_task->task_attr | (ssp_task->task_prio << 3);
-		memcpy(buf_cmd + 12, scsi_cmnd->cmnd, scsi_cmnd->cmd_len);
+		memcpy(buf_cmd + 12, scsi_cmnd->cmnd,
+		       min_t(unsigned short, scsi_cmnd->cmd_len, strlen(buf_cmd)-12));
 	} else {
 		buf_cmd[10] = tmf->tmf;
 		switch (tmf->tmf) {
-- 
2.17.1