From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Guenter Roeck <linux@roeck-us.net>
Date: Tue, 28 Feb 2023 09:11:29 -0800
Subject: [PATCH] scsi: megasas: Internal cdbs have 16-byte length
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Host drivers do not necessarily set cdb_len in megasas io commands.
With commits 6d1511cea0 ("scsi: Reject commands if the CDB length
exceeds buf_len") and fe9d8927e2 ("scsi: Add buf_len parameter to
scsi_req_new()"), this results in failures to boot Linux from affected
SCSI drives because cdb_len is set to 0 by the host driver.
Set the cdb length to its actual size to solve the problem.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
(picked-up from https://lists.nongnu.org/archive/html/qemu-devel/2023-02/msg08653.html)
Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
---
 hw/scsi/megasas.c | 14 ++------------
 1 file changed, 2 insertions(+), 12 deletions(-)

diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index 9cbbb16121..d624866bb6 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -1780,7 +1780,7 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
     uint8_t cdb[16];
     int len;
     struct SCSIDevice *sdev = NULL;
-    int target_id, lun_id, cdb_len;
+    int target_id, lun_id;
 
     lba_count = le32_to_cpu(cmd->frame->io.header.data_len);
     lba_start_lo = le32_to_cpu(cmd->frame->io.lba_lo);
@@ -1789,7 +1789,6 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
 
     target_id = cmd->frame->header.target_id;
     lun_id = cmd->frame->header.lun_id;
-    cdb_len = cmd->frame->header.cdb_len;
 
     if (target_id < MFI_MAX_LD && lun_id == 0) {
         sdev = scsi_device_find(&s->bus, 0, target_id, lun_id);
@@ -1804,15 +1803,6 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
         return MFI_STAT_DEVICE_NOT_FOUND;
     }
 
-    if (cdb_len > 16) {
-        trace_megasas_scsi_invalid_cdb_len(
-            mfi_frame_desc(frame_cmd), 1, target_id, lun_id, cdb_len);
-        megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
-        cmd->frame->header.scsi_status = CHECK_CONDITION;
-        s->event_count++;
-        return MFI_STAT_SCSI_DONE_WITH_ERROR;
-    }
-
     cmd->iov_size = lba_count * sdev->blocksize;
     if (megasas_map_sgl(s, cmd, &cmd->frame->io.sgl)) {
         megasas_write_sense(cmd, SENSE_CODE(TARGET_FAILURE));
@@ -1823,7 +1813,7 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
 
     megasas_encode_lba(cdb, lba_start, lba_count, is_write);
     cmd->req = scsi_req_new(sdev, cmd->index,
-                            lun_id, cdb, cdb_len, cmd);
+                            lun_id, cdb, sizeof(cdb), cmd);
     if (!cmd->req) {
         trace_megasas_scsi_req_alloc_failed(
             mfi_frame_desc(frame_cmd), target_id, lun_id);
