| Message ID | 1464000485-27041-1-git-send-email-ppandit@redhat.com |
|---|---|
| State | New |
| Headers | show |
Hi, On Mon, 23 May 2016 16:18:05 +0530, ppandit@redhat.com wrote: > From: Prasad J Pandit <pjp@fedoraproject.org> > > 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> Reviewed-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
Reviewed-by: Dmitry Fleytman <dmitry@daynix.com> > On 23 May 2016, at 14:16 PM, Shmulik Ladkani <shmulik.ladkani@ravellosystems.com> wrote: > > Hi, > > On Mon, 23 May 2016 16:18:05 +0530, ppandit@redhat.com wrote: >> From: Prasad J Pandit <pjp@fedoraproject.org> >> >> 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> > > Reviewed-by: Shmulik Ladkani <shmulik.ladkani@ravellosystems.com>
On 23/05/2016 12:48, P J P wrote: > From: Prasad J Pandit <pjp@fedoraproject.org> > > 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> > --- > hw/scsi/vmw_pvscsi.c | 24 ++++++++++++++++++++---- > 1 file changed, 20 insertions(+), 4 deletions(-) Is there a CVE number? Thanks, Paolo
+-- On Mon, 23 May 2016, Paolo Bonzini wrote --+ | Is there a CVE number? Yes, CVE-2016-4952: -> https://bugzilla.redhat.com/show_bug.cgi?id=1334384 Thank you. -- Prasad J Pandit / Red Hat Product Security Team 47AF CE69 3A90 54AA 9045 1053 DD13 3D32 FE5B 041F
diff --git a/hw/scsi/vmw_pvscsi.c b/hw/scsi/vmw_pvscsi.c index e690b4e..e1d6d06 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);