From 10bef78e2135fb191166e3893cc4a1326deede8c Mon Sep 17 00:00:00 2001 From: Adrian Dudau Date: Thu, 3 Nov 2016 14:18:01 +0100 Subject: qemu: Security fix CVE-2016-4952 affects qemu < 2.7.0 Quick Emulator(Qemu) built with the VMWARE PVSCSI paravirtual SCSI bus emulation support is vulnerable to an OOB r/w access issue. It could occur while processing SCSI commands 'PVSCSI_CMD_SETUP_RINGS' or 'PVSCSI_CMD_SETUP_MSG_RING'. A privileged user inside guest could use this flaw to crash the Qemu process resulting in DoS. References: ---------- http://www.openwall.com/lists/oss-security/2016/05/23/1 Signed-off-by: Adrian Dudau Signed-off-by: Armin Kuster Signed-off-by: Sona Sarmadi --- .../recipes-devtools/qemu/qemu/CVE-2016-4952.patch | 105 +++++++++++++++++++++ meta/recipes-devtools/qemu/qemu_2.5.0.bb | 1 + 2 files changed, 106 insertions(+) create mode 100644 meta/recipes-devtools/qemu/qemu/CVE-2016-4952.patch diff --git a/meta/recipes-devtools/qemu/qemu/CVE-2016-4952.patch b/meta/recipes-devtools/qemu/qemu/CVE-2016-4952.patch new file mode 100644 index 0000000000..52d2a1e3d0 --- /dev/null +++ b/meta/recipes-devtools/qemu/qemu/CVE-2016-4952.patch @@ -0,0 +1,105 @@ +From 3e831b40e015ba34dfb55ff11f767001839425ff Mon Sep 17 00:00:00 2001 +From: Prasad J Pandit +Date: Mon, 23 May 2016 16:18:05 +0530 +Subject: [PATCH] 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. + +Upstream-Status: Backported + +Reported-by: Li Qiang +Signed-off-by: Prasad J Pandit +Cc: qemu-stable@nongnu.org +Message-Id: <1464000485-27041-1-git-send-email-ppandit@redhat.com> +Reviewed-by: Shmulik Ladkani +Reviewed-by: Dmitry Fleytman +Signed-off-by: Paolo Bonzini +Signed-off-by: Adrian Dudau +--- + 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); +-- +1.7.0.4 + diff --git a/meta/recipes-devtools/qemu/qemu_2.5.0.bb b/meta/recipes-devtools/qemu/qemu_2.5.0.bb index 58902b1988..b965f6916c 100644 --- a/meta/recipes-devtools/qemu/qemu_2.5.0.bb +++ b/meta/recipes-devtools/qemu/qemu_2.5.0.bb @@ -27,6 +27,7 @@ SRC_URI += "file://configure-fix-Darwin-target-detection.patch \ file://CVE-2016-4002.patch \ file://CVE-2016-5403.patch \ file://CVE-2016-4441.patch \ + file://CVE-2016-4952.patch \ " SRC_URI_prepend = "http://wiki.qemu-project.org/download/${BP}.tar.bz2" SRC_URI[md5sum] = "f469f2330bbe76e3e39db10e9ac4f8db" -- cgit v1.2.3-54-g00ecf