megasas: do not read command more than once from frame
Avoid TOC-TOU bugs by passing the frame_cmd down, and checking
cmd->dcmd_opcode instead of cmd->frame->header.frame_cmd.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c
index a3f75c1..38e0a2f 100644
--- a/hw/scsi/megasas.c
+++ b/hw/scsi/megasas.c
@@ -1591,12 +1591,13 @@
}
static int megasas_finish_internal_dcmd(MegasasCmd *cmd,
- SCSIRequest *req)
+ SCSIRequest *req, size_t resid)
{
int retval = MFI_STAT_OK;
int lun = req->lun;
trace_megasas_dcmd_internal_finish(cmd->index, cmd->dcmd_opcode, lun);
+ cmd->iov_size -= resid;
switch (cmd->dcmd_opcode) {
case MFI_DCMD_PD_GET_INFO:
retval = megasas_pd_get_info_submit(req->dev, lun, cmd);
@@ -1649,11 +1650,12 @@
}
static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd,
- bool is_logical)
+ int frame_cmd)
{
uint8_t *cdb;
bool is_write;
struct SCSIDevice *sdev = NULL;
+ bool is_logical = (frame_cmd == MFI_CMD_LD_SCSI_IO);
cdb = cmd->frame->pass.cdb;
@@ -1661,7 +1663,7 @@
if (cmd->frame->header.target_id >= MFI_MAX_LD ||
cmd->frame->header.lun_id != 0) {
trace_megasas_scsi_target_not_present(
- mfi_frame_desc[cmd->frame->header.frame_cmd], is_logical,
+ mfi_frame_desc[frame_cmd], is_logical,
cmd->frame->header.target_id, cmd->frame->header.lun_id);
return MFI_STAT_DEVICE_NOT_FOUND;
}
@@ -1671,19 +1673,20 @@
cmd->iov_size = le32_to_cpu(cmd->frame->header.data_len);
trace_megasas_handle_scsi(mfi_frame_desc[cmd->frame->header.frame_cmd],
- is_logical, cmd->frame->header.target_id,
+ trace_megasas_handle_scsi(mfi_frame_desc[frame_cmd], is_logical,
+ cmd->frame->header.target_id,
cmd->frame->header.lun_id, sdev, cmd->iov_size);
if (!sdev || (megasas_is_jbod(s) && is_logical)) {
trace_megasas_scsi_target_not_present(
- mfi_frame_desc[cmd->frame->header.frame_cmd], is_logical,
+ mfi_frame_desc[frame_cmd], is_logical,
cmd->frame->header.target_id, cmd->frame->header.lun_id);
return MFI_STAT_DEVICE_NOT_FOUND;
}
if (cmd->frame->header.cdb_len > 16) {
trace_megasas_scsi_invalid_cdb_len(
- mfi_frame_desc[cmd->frame->header.frame_cmd], is_logical,
+ mfi_frame_desc[frame_cmd], is_logical,
cmd->frame->header.target_id, cmd->frame->header.lun_id,
cmd->frame->header.cdb_len);
megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
@@ -1703,7 +1706,7 @@
cmd->frame->header.lun_id, cdb, cmd);
if (!cmd->req) {
trace_megasas_scsi_req_alloc_failed(
- mfi_frame_desc[cmd->frame->header.frame_cmd],
+ mfi_frame_desc[frame_cmd],
cmd->frame->header.target_id, cmd->frame->header.lun_id);
megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
cmd->frame->header.scsi_status = BUSY;
@@ -1725,11 +1728,11 @@
return MFI_STAT_INVALID_STATUS;
}
-static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd)
+static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd, int frame_cmd)
{
uint32_t lba_count, lba_start_hi, lba_start_lo;
uint64_t lba_start;
- bool is_write = (cmd->frame->header.frame_cmd == MFI_CMD_LD_WRITE);
+ bool is_write = (frame_cmd == MFI_CMD_LD_WRITE);
uint8_t cdb[16];
int len;
struct SCSIDevice *sdev = NULL;
@@ -1746,20 +1749,20 @@
}
trace_megasas_handle_io(cmd->index,
- mfi_frame_desc[cmd->frame->header.frame_cmd],
+ mfi_frame_desc[frame_cmd],
cmd->frame->header.target_id,
cmd->frame->header.lun_id,
(unsigned long)lba_start, (unsigned long)lba_count);
if (!sdev) {
trace_megasas_io_target_not_present(cmd->index,
- mfi_frame_desc[cmd->frame->header.frame_cmd],
+ mfi_frame_desc[frame_cmd],
cmd->frame->header.target_id, cmd->frame->header.lun_id);
return MFI_STAT_DEVICE_NOT_FOUND;
}
if (cmd->frame->header.cdb_len > 16) {
trace_megasas_scsi_invalid_cdb_len(
- mfi_frame_desc[cmd->frame->header.frame_cmd], 1,
+ mfi_frame_desc[frame_cmd], 1,
cmd->frame->header.target_id, cmd->frame->header.lun_id,
cmd->frame->header.cdb_len);
megasas_write_sense(cmd, SENSE_CODE(INVALID_OPCODE));
@@ -1781,7 +1784,7 @@
cmd->frame->header.lun_id, cdb, cmd);
if (!cmd->req) {
trace_megasas_scsi_req_alloc_failed(
- mfi_frame_desc[cmd->frame->header.frame_cmd],
+ mfi_frame_desc[frame_cmd],
cmd->frame->header.target_id, cmd->frame->header.lun_id);
megasas_write_sense(cmd, SENSE_CODE(NO_SENSE));
cmd->frame->header.scsi_status = BUSY;
@@ -1799,23 +1802,11 @@
return MFI_STAT_INVALID_STATUS;
}
-static int megasas_finish_internal_command(MegasasCmd *cmd,
- SCSIRequest *req, size_t resid)
-{
- int retval = MFI_STAT_INVALID_CMD;
-
- if (cmd->frame->header.frame_cmd == MFI_CMD_DCMD) {
- cmd->iov_size -= resid;
- retval = megasas_finish_internal_dcmd(cmd, req);
- }
- return retval;
-}
-
static QEMUSGList *megasas_get_sg_list(SCSIRequest *req)
{
MegasasCmd *cmd = req->hba_private;
- if (cmd->frame->header.frame_cmd == MFI_CMD_DCMD) {
+ if (cmd->dcmd_opcode != -1) {
return NULL;
} else {
return &cmd->qsg;
@@ -1829,7 +1820,7 @@
trace_megasas_io_complete(cmd->index, len);
- if (cmd->frame->header.frame_cmd != MFI_CMD_DCMD) {
+ if (cmd->dcmd_opcode != -1) {
scsi_req_continue(req);
return;
}
@@ -1872,7 +1863,7 @@
/*
* Internal command complete
*/
- cmd_status = megasas_finish_internal_command(cmd, req, resid);
+ cmd_status = megasas_finish_internal_dcmd(cmd, req, resid);
if (cmd_status == MFI_STAT_INVALID_STATUS) {
return;
}
@@ -1943,6 +1934,7 @@
{
uint8_t frame_status = MFI_STAT_INVALID_CMD;
uint64_t frame_context;
+ int frame_cmd;
MegasasCmd *cmd;
/*
@@ -1961,7 +1953,8 @@
s->event_count++;
return;
}
- switch (cmd->frame->header.frame_cmd) {
+ frame_cmd = cmd->frame->header.frame_cmd;
+ switch (frame_cmd) {
case MFI_CMD_INIT:
frame_status = megasas_init_firmware(s, cmd);
break;
@@ -1972,18 +1965,15 @@
frame_status = megasas_handle_abort(s, cmd);
break;
case MFI_CMD_PD_SCSI_IO:
- frame_status = megasas_handle_scsi(s, cmd, 0);
- break;
case MFI_CMD_LD_SCSI_IO:
- frame_status = megasas_handle_scsi(s, cmd, 1);
+ frame_status = megasas_handle_scsi(s, cmd, frame_cmd);
break;
case MFI_CMD_LD_READ:
case MFI_CMD_LD_WRITE:
- frame_status = megasas_handle_io(s, cmd);
+ frame_status = megasas_handle_io(s, cmd, frame_cmd);
break;
default:
- trace_megasas_unhandled_frame_cmd(cmd->index,
- cmd->frame->header.frame_cmd);
+ trace_megasas_unhandled_frame_cmd(cmd->index, frame_cmd);
s->event_count++;
break;
}
