Commit 87e459a8 authored by Paolo Bonzini's avatar Paolo Bonzini
Browse files

megasas: always store SCSIRequest* into MegasasCmd 



This ensures that the request is unref'ed properly, and avoids a
segmentation fault in the new qtest testcase that is added.
This is CVE-2017-9503.

Reported-by: default avatarZhangyanyu <zyy4013@stu.ouc.edu.cn>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent b356807f

hw/scsi/megasas.c

+16 −15
Original line number Diff line number Diff line
@@ -609,6 +609,9 @@ static void megasas_reset_frames(MegasasState *s) 
static void megasas_abort_command(MegasasCmd *cmd)

{

    /* Never abort internal commands.  */

    if (cmd->dcmd_opcode != -1) {

        return;

    }

    if (cmd->req != NULL) {

        scsi_req_cancel(cmd->req);

    }
@@ -1017,7 +1020,6 @@ static int megasas_pd_get_info_submit(SCSIDevice *sdev, int lun, 
    uint64_t pd_size;

    uint16_t pd_id = ((sdev->id & 0xFF) << 8) | (lun & 0xFF);

    uint8_t cmdbuf[6];

    SCSIRequest *req;

    size_t len, resid;



    if (!cmd->iov_buf) {
@@ -1026,8 +1028,8 @@ static int megasas_pd_get_info_submit(SCSIDevice *sdev, int lun, 
        info->inquiry_data[0] = 0x7f; /* Force PQual 0x3, PType 0x1f */

        info->vpd_page83[0] = 0x7f;

        megasas_setup_inquiry(cmdbuf, 0, sizeof(info->inquiry_data));

        req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);

        if (!req) {

        cmd->req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);

        if (!cmd->req) {

            trace_megasas_dcmd_req_alloc_failed(cmd->index,

                                                "PD get info std inquiry");

            g_free(cmd->iov_buf);
@@ -1036,26 +1038,26 @@ static int megasas_pd_get_info_submit(SCSIDevice *sdev, int lun, 
        }

        trace_megasas_dcmd_internal_submit(cmd->index,

                                           "PD get info std inquiry", lun);

        len = scsi_req_enqueue(req);

        len = scsi_req_enqueue(cmd->req);

        if (len > 0) {

            cmd->iov_size = len;

            scsi_req_continue(req);

            scsi_req_continue(cmd->req);

        }

        return MFI_STAT_INVALID_STATUS;

    } else if (info->inquiry_data[0] != 0x7f && info->vpd_page83[0] == 0x7f) {

        megasas_setup_inquiry(cmdbuf, 0x83, sizeof(info->vpd_page83));

        req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);

        if (!req) {

        cmd->req = scsi_req_new(sdev, cmd->index, lun, cmdbuf, cmd);

        if (!cmd->req) {

            trace_megasas_dcmd_req_alloc_failed(cmd->index,

                                                "PD get info vpd inquiry");

            return MFI_STAT_FLASH_ALLOC_FAIL;

        }

        trace_megasas_dcmd_internal_submit(cmd->index,

                                           "PD get info vpd inquiry", lun);

        len = scsi_req_enqueue(req);

        len = scsi_req_enqueue(cmd->req);

        if (len > 0) {

            cmd->iov_size = len;

            scsi_req_continue(req);

            scsi_req_continue(cmd->req);

        }

        return MFI_STAT_INVALID_STATUS;

    }
@@ -1217,7 +1219,6 @@ static int megasas_ld_get_info_submit(SCSIDevice *sdev, int lun, 
    struct mfi_ld_info *info = cmd->iov_buf;

    size_t dcmd_size = sizeof(struct mfi_ld_info);

    uint8_t cdb[6];

    SCSIRequest *req;

    ssize_t len, resid;

    uint16_t sdev_id = ((sdev->id & 0xFF) << 8) | (lun & 0xFF);

    uint64_t ld_size;
@@ -1226,8 +1227,8 @@ static int megasas_ld_get_info_submit(SCSIDevice *sdev, int lun, 
        cmd->iov_buf = g_malloc0(dcmd_size);

        info = cmd->iov_buf;

        megasas_setup_inquiry(cdb, 0x83, sizeof(info->vpd_page83));

        req = scsi_req_new(sdev, cmd->index, lun, cdb, cmd);

        if (!req) {

        cmd->req = scsi_req_new(sdev, cmd->index, lun, cdb, cmd);

        if (!cmd->req) {

            trace_megasas_dcmd_req_alloc_failed(cmd->index,

                                                "LD get info vpd inquiry");

            g_free(cmd->iov_buf);
@@ -1236,10 +1237,10 @@ static int megasas_ld_get_info_submit(SCSIDevice *sdev, int lun, 
        }

        trace_megasas_dcmd_internal_submit(cmd->index,

                                           "LD get info vpd inquiry", lun);

        len = scsi_req_enqueue(req);

        len = scsi_req_enqueue(cmd->req);

        if (len > 0) {

            cmd->iov_size = len;

            scsi_req_continue(req);

            scsi_req_continue(cmd->req);

        }

        return MFI_STAT_INVALID_STATUS;

    }
@@ -1851,7 +1852,7 @@ static void megasas_command_complete(SCSIRequest *req, uint32_t status, 
        return;

    }



    if (cmd->req == NULL) {

    if (cmd->dcmd_opcode != -1) {

        /*

         * Internal command complete

         */

tests/megasas-test.c

+35 −0
Original line number Diff line number Diff line
@@ -42,10 +42,45 @@ static void pci_nop(void) 
    qmegasas_stop(qs);

}



/* This used to cause a NULL pointer dereference.  */

static void megasas_pd_get_info_fuzz(void)

{

    QPCIDevice *dev;

    QOSState *qs;

    QPCIBar bar;

    uint32_t context[256];

    uint64_t context_pa;

    int i;



    qs = qmegasas_start(NULL);

    dev = qpci_device_find(qs->pcibus, QPCI_DEVFN(4,0));

    g_assert(dev != NULL);



    qpci_device_enable(dev);

    bar = qpci_iomap(dev, 0, NULL);



    memset(context, 0, sizeof(context));

    context[0] = cpu_to_le32(0x05050505);

    context[1] = cpu_to_le32(0x01010101);

    for (i = 2; i < ARRAY_SIZE(context); i++) {

        context[i] = cpu_to_le32(0x41414141);

    }

    context[6] = cpu_to_le32(0x02020000);

    context[7] = cpu_to_le32(0);



    context_pa = qmalloc(qs, sizeof(context));

    memwrite(context_pa, context, sizeof(context));

    qpci_io_writel(dev, bar, 0x40, context_pa);



    g_free(dev);

    qmegasas_stop(qs);

}



int main(int argc, char **argv)

{

    g_test_init(&argc, &argv, NULL);

    qtest_add_func("/megasas/pci/nop", pci_nop);

    qtest_add_func("/megasas/dcmd/pd-get-info/fuzz", megasas_pd_get_info_fuzz);



    return g_test_run();

}