CVE-2016-4480

The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen 4.6.x and earlier does not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might allow local guest OS users to gain privileges via a crafted mapping of memory.

This xen update is based on upstream 4.5.5 maintenance release, and fixes the following security issues:

The qemu implementation in libvirt before 1.3.0 and Xen allows local guest OS users to cause a denial of service (host disk consumption) by writing to stdout or stderr (CVE-2014-3672)

The xrstor function in arch/x86/xstate.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076 (CVE-2016-3158).

The fpu_fxrstor function in arch/x86/i387.c in Xen 4.x does not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allows local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits. NOTE: this vulnerability exists because of an incorrect fix for CVE-2013-2076 (CVE-2016-3159).

The VGA module in QEMU improperly performs bounds checking on banked access to video memory, which allows local guest OS administrators to execute arbitrary code on the host by changing access modes after setting the bank register, aka the "Dark Portal" issue (CVE-2016-3710).

Integer overflow in the VGA module in QEMU allows local guest OS users to cause a denial of service (out-of-bounds read and QEMU process crash) by editing VGA registers in VBE mode (CVE-2016-3712).

Integer overflow in the x86 shadow pagetable code in Xen allows local guest OS users to cause a denial of service (host crash) or possibly gain privileges by shadowing a superpage mapping (CVE-2016-3960).

The libxl device-handling in Xen 4.6.x and earlier allows local OS guest administrators to cause a denial of service (resource consumption or management facility confusion) or gain host OS privileges by manipulating information in guest controlled areas of xenstore (CVE-2016-4962).

The libxl device-handling in Xen through 4.6.x allows local guest OS users with access to the driver domain to cause a denial of service (management tool confusion) by manipulating information in the backend directories in xenstore (CVE-2016-4963).

The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen 4.6.x and earlier does not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might allow local guest OS users to gain privileges via a crafted mapping of memory (CVE-2016-4480).

The p2m_teardown function in arch/arm/p2m.c in Xen 4.4.x through 4.6.x allows local guest OS users with access to the driver domain to cause a denial of service (NULL pointer dereference and host OS crash) by creating concurrent domains and holding references to them, related to VMID exhaustion (CVE-2016-5242).

The virtqueue_pop function in hw/virtio/virtio.c in QEMU allows local guest OS administrators to cause a denial of service (memory consumption and QEMU process crash) by submitting requests without waiting for completion (CVE-2016-5403).

The PV pagetable code in arch/x86/mm.c in Xen 4.7.x and earlier allows local 32-bit PV guest OS administrators to gain host OS privileges by leveraging fast-paths for updating pagetable entries (CVE-2016-6258).

Xen 4.5.x through 4.7.x do not implement Supervisor Mode Access Prevention (SMAP) whitelisting in 32-bit exception and event delivery, which allows local 32-bit PV guest OS kernels to cause a denial of service (hypervisor and VM crash) by triggering a safety check (CVE-2016-6259).

The get_page_from_l3e function in arch/x86/mm.c in Xen allows local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables (CVE-2016-7092).

Xen 4.5.3, 4.6.3, and 4.7.x allow local HVM guest OS administrators to overwrite hypervisor memory and consequently gain host OS privileges by leveraging mishandling of…

This update for xen fixes several issues.

These security issues were fixed:

• CVE-2016-7094: Buffer overflow in Xen allowed local x86 HVM guest OS administrators on guests running with shadow paging to cause a denial of service via a pagetable update (bsc#995792)
• CVE-2016-7092: The get_page_from_l3e function in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables (bsc#995785)
• CVE-2016-6258: The PV pagetable code in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges by leveraging fast-paths for updating pagetable entries (bsc#988675)
• CVE-2016-5338: The (1) esp_reg_read and (2) esp_reg_write functions allowed local guest OS administrators to cause a denial of service (QEMU process crash) or execute arbitrary code on the host via vectors related to the information transfer buffer (bsc#983984)
• CVE-2016-5238: The get_cmd function in hw/scsi/esp.c might have allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via vectors related to reading from the information transfer buffer in non-DMA mode (bsc#982960)
• CVE-2014-3672: The qemu implementation in libvirt Xen allowed local guest OS users to cause a denial of service (host disk consumption) by writing to stdout or stderr (bsc#981264)
• CVE-2016-4441: The get_cmd function in the 53C9X Fast SCSI Controller (FSC) support did not properly check DMA length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via unspecified vectors, involving an SCSI command (bsc#980724)
• CVE-2016-4439: The esp_reg_write function in the 53C9X Fast SCSI Controller (FSC) support did not properly check command buffer length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) or potentially execute arbitrary code on the host via unspecified vectors (bsc#980716)
• CVE-2016-3710: The VGA module improperly performed bounds checking on banked access to video memory, which allowed local guest OS administrators to execute arbitrary code on the host by changing access modes after setting the bank register, aka the 'Dark Portal' issue (bsc#978164)
• CVE-2016-4480: The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen did not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might have allowed local guest OS users to gain privileges via a crafted mapping of memory (bsc#978295)
• CVE-2016-3960: Integer overflow in the x86 shadow pagetable code allowed local guest OS users to cause a denial of service (host crash) or possibly gain privileges by shadowing a superpage mapping (bsc#974038)
• CVE-2016-3158: The xrstor function did not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allowed local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits (bsc#973188)
• CVE-2016-4001: Buffer overflow in the stellaris_enet_receive function, when the Stellaris ethernet controller is configured to accept large packets, allowed remote attackers to cause a denial of service (QEMU crash) via a large packet (bsc#975130)
• CVE-2016-4002: Buffer overflow in the mipsnet_receive function, when the guest NIC is configured to accept large packets, allowed remote attackers to cause a denial of service (memory corruption and QEMU crash) or possibly execute arbitrary code via a packet larger than 1514 bytes (bsc#975138)

This update for xen fixes several issues.

These security issues were fixed:

• CVE-2014-3672: The qemu implementation in libvirt Xen allowed local guest OS users to cause a denial of service (host disk consumption) by writing to stdout or stderr (bsc#981264).
• CVE-2016-3158: The xrstor function did not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allowed local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits (bsc#973188).
• CVE-2016-3159: The fpu_fxrstor function in arch/x86/i387.c did not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allowed local guest OS users to obtain sensitive register content information from another guest by leveraging pending exception and mask bits (bsc#973188).
• CVE-2016-3710: The VGA module improperly performed bounds checking on banked access to video memory, which allowed local guest OS administrators to execute arbitrary code on the host by changing access modes after setting the bank register, aka the 'Dark Portal' issue (bsc#978164)
• CVE-2016-3960: Integer overflow in the x86 shadow pagetable code allowed local guest OS users to cause a denial of service (host crash) or possibly gain privileges by shadowing a superpage mapping (bsc#974038).
• CVE-2016-4001: Buffer overflow in the stellaris_enet_receive function, when the Stellaris ethernet controller is configured to accept large packets, allowed remote attackers to cause a denial of service (QEMU crash) via a large packet (bsc#975130).
• CVE-2016-4002: Buffer overflow in the mipsnet_receive function, when the guest NIC is configured to accept large packets, allowed remote attackers to cause a denial of service (memory corruption and QEMU crash) or possibly execute arbitrary code via a packet larger than 1514 bytes (bsc#975138).
• CVE-2016-4020: The patch_instruction function did not initialize the imm32 variable, which allowed local guest OS administrators to obtain sensitive information from host stack memory by accessing the Task Priority Register (TPR) (bsc#975907)
• CVE-2016-4037: The ehci_advance_state function in hw/usb/hcd-ehci.c allowed local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via a circular split isochronous transfer descriptor (siTD) list (bsc#976111)
• CVE-2016-4439: The esp_reg_write function in the 53C9X Fast SCSI Controller (FSC) support did not properly check command buffer length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) or potentially execute arbitrary code on the host via unspecified vectors (bsc#980716)
• CVE-2016-4441: The get_cmd function in the 53C9X Fast SCSI Controller (FSC) support did not properly check DMA length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via unspecified vectors, involving an SCSI command (bsc#980724)
• CVE-2016-4453: The vmsvga_fifo_run function allowed local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command (bsc#982225)
• CVE-2016-4454: The vmsvga_fifo_read_raw function allowed local guest OS administrators to obtain sensitive host memory information or cause a denial of service (QEMU process crash) by changing FIFO registers and issuing a VGA command, which triggered an out-of-bounds read (bsc#982224)
• CVE-2016-4480: The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen did not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might have allowed local guest OS users to gain privileges via a crafted mapping of memory (bsc#978295).
• CVE-2016-4952: Out-of-bounds access issue in pvsci_ring_init_msg/data routines (bsc#981276)
• CVE-2016-4962: The libxl device-handling allowed local OS guest administrators to…

This update for xen fixes several issues.

These security issues were fixed:

• CVE-2016-7094: Buffer overflow in Xen allowed local x86 HVM guest OS administrators on guests running with shadow paging to cause a denial of service via a pagetable update (bsc#995792)
• CVE-2016-7092: The get_page_from_l3e function in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges via vectors related to L3 recursive pagetables (bsc#995785)
• CVE-2016-5403: Unbounded memory allocation allowed a guest administrator to cause a denial of service of the host (bsc#990923)
• CVE-2016-6351: The esp_do_dma function in hw/scsi/esp.c, when built with ESP/NCR53C9x controller emulation support, allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) or execute arbitrary code on the host via vectors involving DMA read into ESP command buffer (bsc#990843)
• CVE-2016-6258: The PV pagetable code in arch/x86/mm.c in Xen allowed local 32-bit PV guest OS administrators to gain host OS privileges by leveraging fast-paths for updating pagetable entries (bsc#988675)
• CVE-2016-5338: The (1) esp_reg_read and (2) esp_reg_write functions allowed local guest OS administrators to cause a denial of service (QEMU process crash) or execute arbitrary code on the host via vectors related to the information transfer buffer (bsc#983984)
• CVE-2016-5238: The get_cmd function in hw/scsi/esp.c might have allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via vectors related to reading from the information transfer buffer in non-DMA mode (bsc#982960)
• CVE-2016-4453: The vmsvga_fifo_run function allowed local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command (bsc#982225)
• CVE-2016-4454: The vmsvga_fifo_read_raw function allowed local guest OS administrators to obtain sensitive host memory information or cause a denial of service (QEMU process crash) by changing FIFO registers and issuing a VGA command, which triggered an out-of-bounds read (bsc#982224)
• CVE-2014-3672: The qemu implementation in libvirt Xen allowed local guest OS users to cause a denial of service (host disk consumption) by writing to stdout or stderr (bsc#981264)
• CVE-2016-4441: The get_cmd function in the 53C9X Fast SCSI Controller (FSC) support did not properly check DMA length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) via unspecified vectors, involving an SCSI command (bsc#980724)
• CVE-2016-4439: The esp_reg_write function in the 53C9X Fast SCSI Controller (FSC) support did not properly check command buffer length, which allowed local guest OS administrators to cause a denial of service (out-of-bounds write and QEMU process crash) or potentially execute arbitrary code on the host via unspecified vectors (bsc#980716)
• CVE-2016-3710: The VGA module improperly performed bounds checking on banked access to video memory, which allowed local guest OS administrators to execute arbitrary code on the host by changing access modes after setting the bank register, aka the 'Dark Portal' issue (bsc#978164)
• CVE-2016-4480: The guest_walk_tables function in arch/x86/mm/guest_walk.c in Xen did not properly handle the Page Size (PS) page table entry bit at the L4 and L3 page table levels, which might have allowed local guest OS users to gain privileges via a crafted mapping of memory (bsc#978295)
• CVE-2016-3960: Integer overflow in the x86 shadow pagetable code allowed local guest OS users to cause a denial of service (host crash) or possibly gain privileges by shadowing a superpage mapping (bsc#974038)
• CVE-2016-3158: The xrstor function did not properly handle writes to the hardware FSW.ES bit when running on AMD64 processors, which allowed local guest OS users to obtain sensitive register content information from another…