82 lines
2.7 KiB
Diff
82 lines
2.7 KiB
Diff
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From: Prasad J Pandit <address@hidden>
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Vmware Paravirtual SCSI emulation uses command descriptors to
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process SCSI commands. These descriptors come with their ring
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buffers. A guest could set the page count for these rings to
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an arbitrary value, leading to infinite loop or OOB access.
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Add check to avoid it.
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Reported-by: Tom Victor <address@hidden>
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Reported-by: Li Qiang <address@hidden>
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Signed-off-by: Prasad J Pandit <address@hidden>
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---
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hw/scsi/vmw_pvscsi.c | 21 ++++++++++-----------
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1 file changed, 10 insertions(+), 11 deletions(-)
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Update per review
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-> https://lists.gnu.org/archive/html/qemu-devel/2016-09/msg00019.html
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diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c
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index 5116f4a..4245c15 100644
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--- a/hw/scsi/vmw_pvscsi.c
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+++ b/hw/scsi/vmw_pvscsi.c
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@@ -152,7 +152,7 @@ pvscsi_log2(uint32_t input)
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return log;
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}
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-static int
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+static void
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pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri)
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{
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int i;
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@@ -160,10 +160,6 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri)
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uint32_t req_ring_size, cmp_ring_size;
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m->rs_pa = ri->ringsStatePPN << VMW_PAGE_SHIFT;
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- if ((ri->reqRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)
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- || (ri->cmpRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)) {
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- return -1;
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- }
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req_ring_size = ri->reqRingNumPages * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE;
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cmp_ring_size = ri->cmpRingNumPages * PVSCSI_MAX_NUM_CMP_ENTRIES_PER_PAGE;
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txr_len_log2 = pvscsi_log2(req_ring_size - 1);
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@@ -195,8 +191,6 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri)
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/* Flush ring state page changes */
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smp_wmb();
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-
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- return 0;
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}
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static int
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@@ -746,7 +740,7 @@ pvscsi_dbg_dump_tx_rings_config(PVSCSICmdDescSetupRings *rc)
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trace_pvscsi_tx_rings_num_pages("Confirm Ring", rc->cmpRingNumPages);
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for (i = 0; i < rc->cmpRingNumPages; i++) {
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- trace_pvscsi_tx_rings_ppn("Confirm Ring", rc->reqRingPPNs[i]);
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+ trace_pvscsi_tx_rings_ppn("Confirm Ring", rc->cmpRingPPNs[i]);
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}
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}
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@@ -779,10 +773,15 @@ pvscsi_on_cmd_setup_rings(PVSCSIState *s)
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trace_pvscsi_on_cmd_arrived("PVSCSI_CMD_SETUP_RINGS");
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+ if (!rc->reqRingNumPages
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+ || rc->reqRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES
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+ || !rc->cmpRingNumPages
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+ || rc->cmpRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES) {
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+ return PVSCSI_COMMAND_PROCESSING_FAILED;
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+ }
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+
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pvscsi_dbg_dump_tx_rings_config(rc);
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- if (pvscsi_ring_init_data(&s->rings, rc) < 0) {
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- return PVSCSI_COMMAND_PROCESSING_FAILED;
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- }
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+ pvscsi_ring_init_data(&s->rings, rc);
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s->rings_info_valid = TRUE;
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return PVSCSI_COMMAND_PROCESSING_SUCCEEDED;
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--
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2.5.5
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