From 87e459a810d7b1ec1638085b5a80ea3d9b43119a Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 1 Jun 2017 17:26:14 +0200 Subject: [PATCH] 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: Zhangyanyu Signed-off-by: Paolo Bonzini --- hw/scsi/megasas.c | 31 ++++++++++++++++--------------- tests/megasas-test.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 15 deletions(-) diff --git a/hw/scsi/megasas.c b/hw/scsi/megasas.c index 135662df31..734fdaef90 100644 --- a/hw/scsi/megasas.c +++ b/hw/scsi/megasas.c @@ -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 */ diff --git a/tests/megasas-test.c b/tests/megasas-test.c index a9e56a2389..ce960e7f81 100644 --- a/tests/megasas-test.c +++ b/tests/megasas-test.c @@ -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(); }