From: Paolo Bonzini Date: Thu, 1 Jun 2017 17:23:13 +0200 Subject: [PATCH] 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 (cherry picked from commit 36c327a69d723571f02a7691631667cdb1865ee1) --- hw/scsi/megasas.c | 60 +++++++++++++++++++++++-------------------------------- 1 file changed, 25 insertions(+), 35 deletions(-) diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c index a3f75c1650..38e0a2f5ef 100644 --- a/hw/scsi/megasas.c +++ b/hw/scsi/megasas.c @@ -1591,12 +1591,13 @@ static int megasas_handle_dcmd(MegasasState *s, MegasasCmd *cmd) } 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_enqueue_req(MegasasCmd *cmd, bool is_write) } 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 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd, 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 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd, 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 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd, 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 @@ static int megasas_handle_scsi(MegasasState *s, MegasasCmd *cmd, 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 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd) } 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 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd) 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 @@ static int megasas_handle_io(MegasasState *s, MegasasCmd *cmd) 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 @@ static void megasas_xfer_complete(SCSIRequest *req, uint32_t len) 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 @@ static void megasas_command_complete(SCSIRequest *req, uint32_t status, /* * 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 @@ static void megasas_handle_frame(MegasasState *s, uint64_t frame_addr, { uint8_t frame_status = MFI_STAT_INVALID_CMD; uint64_t frame_context; + int frame_cmd; MegasasCmd *cmd; /* @@ -1961,7 +1953,8 @@ static void megasas_handle_frame(MegasasState *s, uint64_t frame_addr, 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 @@ static void megasas_handle_frame(MegasasState *s, uint64_t frame_addr, 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; }