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| author | Prasad J Pandit <pjp@fedoraproject.org> | 2016-05-23 16:18:05 +0530 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2016-05-29 09:11:10 +0200 |
| commit | 3e831b40e015ba34dfb55ff11f767001839425ff (patch) | |
| tree | fbaa5e3c5ffaacb7ac16319a71732abadcf4df36 /hw/scsi/vmw_pvscsi.c | |
| parent | 60b412dd18362bd4ddc44ba7022aacb6af074b5d (diff) | |
| download | qemu-3e831b40e015ba34dfb55ff11f767001839425ff.zip qemu-3e831b40e015ba34dfb55ff11f767001839425ff.tar.gz qemu-3e831b40e015ba34dfb55ff11f767001839425ff.tar.bz2 | |
scsi: pvscsi: check command descriptor ring buffer size (CVE-2016-4952)
Vmware Paravirtual SCSI emulation uses command descriptors to
process SCSI commands. These descriptors come with their ring
buffers. A guest could set the ring buffer size to an arbitrary
value leading to OOB access issue. Add check to avoid it.
Reported-by: Li Qiang <liqiang6-s@360.cn>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Cc: qemu-stable@nongnu.org
Message-Id: <1464000485-27041-1-git-send-email-ppandit@redhat.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Reviewed-by: Dmitry Fleytman <dmitry@daynix.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'hw/scsi/vmw_pvscsi.c')
| -rw-r--r-- | hw/scsi/vmw_pvscsi.c | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c index f67b5bf..2d7528d 100644 --- a/hw/scsi/vmw_pvscsi.c +++ b/hw/scsi/vmw_pvscsi.c @@ -153,7 +153,7 @@ pvscsi_log2(uint32_t input) return log; } -static void +static int pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri) { int i; @@ -161,6 +161,10 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri) uint32_t req_ring_size, cmp_ring_size; m->rs_pa = ri->ringsStatePPN << VMW_PAGE_SHIFT; + if ((ri->reqRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES) + || (ri->cmpRingNumPages > PVSCSI_SETUP_RINGS_MAX_NUM_PAGES)) { + return -1; + } req_ring_size = ri->reqRingNumPages * PVSCSI_MAX_NUM_REQ_ENTRIES_PER_PAGE; cmp_ring_size = ri->cmpRingNumPages * PVSCSI_MAX_NUM_CMP_ENTRIES_PER_PAGE; txr_len_log2 = pvscsi_log2(req_ring_size - 1); @@ -192,15 +196,20 @@ pvscsi_ring_init_data(PVSCSIRingInfo *m, PVSCSICmdDescSetupRings *ri) /* Flush ring state page changes */ smp_wmb(); + + return 0; } -static void +static int pvscsi_ring_init_msg(PVSCSIRingInfo *m, PVSCSICmdDescSetupMsgRing *ri) { int i; uint32_t len_log2; uint32_t ring_size; + if (ri->numPages > PVSCSI_SETUP_MSG_RING_MAX_NUM_PAGES) { + return -1; + } ring_size = ri->numPages * PVSCSI_MAX_NUM_MSG_ENTRIES_PER_PAGE; len_log2 = pvscsi_log2(ring_size - 1); @@ -220,6 +229,8 @@ pvscsi_ring_init_msg(PVSCSIRingInfo *m, PVSCSICmdDescSetupMsgRing *ri) /* Flush ring state page changes */ smp_wmb(); + + return 0; } static void @@ -770,7 +781,10 @@ pvscsi_on_cmd_setup_rings(PVSCSIState *s) trace_pvscsi_on_cmd_arrived("PVSCSI_CMD_SETUP_RINGS"); pvscsi_dbg_dump_tx_rings_config(rc); - pvscsi_ring_init_data(&s->rings, rc); + if (pvscsi_ring_init_data(&s->rings, rc) < 0) { + return PVSCSI_COMMAND_PROCESSING_FAILED; + } + s->rings_info_valid = TRUE; return PVSCSI_COMMAND_PROCESSING_SUCCEEDED; } @@ -850,7 +864,9 @@ pvscsi_on_cmd_setup_msg_ring(PVSCSIState *s) } if (s->rings_info_valid) { - pvscsi_ring_init_msg(&s->rings, rc); + if (pvscsi_ring_init_msg(&s->rings, rc) < 0) { + return PVSCSI_COMMAND_PROCESSING_FAILED; + } s->msg_ring_info_valid = TRUE; } return sizeof(PVSCSICmdDescSetupMsgRing) / sizeof(uint32_t); |