An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service because of an incompatibility between Process Context Identifiers (PCID) and shadow-pagetable switching.

An issue was discovered in Xen through 4.11.x allowing x86 PV guest OS users to cause a denial of service by leveraging a long-running operation that exists to support restartability of PTE updates.

An issue was discovered in drivers/xen/balloon.c in the Linux kernel before 5.2.3, as used in Xen through 4.12.x, allowing guest OS users to cause a denial of service because of unrestricted resource consumption during the mapping of guest memory, aka CID-6ef36ab967c7.

An issue was discovered in Xen 4.8.x through 4.10.x allowing x86 PVH guest OS users to cause a denial of service (NULL pointer dereference and hypervisor crash) by leveraging the mishandling of configurations that lack a Local APIC.

An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (host OS CPU hang) via non-preemptable L3/L4 pagetable freeing.

An issue was discovered in Xen through 4.11.x on Intel x86 platforms allowing guest OS users to cause a denial of service (host OS hang) because Xen does not work around Intel's mishandling of certain HLE transactions associated with the KACQUIRE instruction prefix.

An issue was discovered in Xen through 4.11.x. ARM never properly implemented grant table v2, either in the hypervisor or in Linux. Unfortunately, an ARM guest can still request v2 grant tables; they will simply not be properly set up, resulting in subsequent grant-related hypercalls hitting BUG() checks. An unprivileged guest can cause a BUG() check in the hypervisor, resulting in a denial-of-service (crash).

An issue was discovered in Xen through 4.11.x. The DEBUGCTL MSR contains several debugging features, some of which virtualise cleanly, but some do not. In particular, Branch Trace Store is not virtualised by the processor, and software has to be careful to configure it suitably not to lock up the core. As a result, it must only be available to fully trusted guests. Unfortunately, in the case that vPMU is disabled, all value checking was skipped, allowing the guest to choose any MSR_DEBUGCTL setting it likes. A malicious or buggy guest administrator (on Intel x86 HVM or PVH) can lock up the entire host, causing a Denial of Service.

An issue was discovered in Xen through 4.11.x. The logic in oxenstored for handling writes depended on the order of evaluation of expressions making up a tuple. As indicated in section 7.7.3 "Operations on data structures" of the OCaml manual, the order of evaluation of subexpressions is not specified. In practice, different implementations behave differently. Thus, oxenstored may not enforce the configured quota-maxentity. This allows a malicious or buggy guest to write as many xenstore entries as it wishes, causing unbounded memory usage in oxenstored. This can lead to a system-wide DoS.

An issue was discovered in Xen through 4.10.x. Certain PV MMU operations may take a long time to process. For that reason Xen explicitly checks for the need to preempt the current vCPU at certain points. A few rarely taken code paths did bypass such checks. By suitably enforcing the conditions through its own page table contents, a malicious guest may cause such bypasses to be used for an unbounded number of iterations. A malicious or buggy PV guest may cause a Denial of Service (DoS) affecting the entire host. Specifically, it may prevent use of a physical CPU for an indeterminate period of time. All Xen versions from 3.4 onwards are vulnerable. Xen versions 3.3 and earlier are vulnerable to an even wider class of attacks, due to them lacking preemption checks altogether in the affected code paths. Only x86 systems are affected. ARM systems are not affected. Only multi-vCPU x86 PV guests can leverage the vulnerability. x86 HVM or PVH guests as well as x86 single-vCPU PV ones cannot leverage the vulnerability.

An issue was discovered in Xen through 4.10.x. One of the fixes in XSA-260 added some safety checks to help prevent Xen livelocking with debug exceptions. Unfortunately, due to an oversight, at least one of these safety checks can be triggered by a guest. A malicious PV guest can crash Xen, leading to a Denial of Service. All Xen systems which have applied the XSA-260 fix are vulnerable. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only x86 PV guests can exploit the vulnerability. x86 HVM and PVH guests cannot exploit the vulnerability. An attacker needs to be able to control hardware debugging facilities to exploit the vulnerability, but such permissions are typically available to unprivileged users.

An issue was discovered in Xen through 4.10.x allowing x86 PV guest OS users to cause a denial of service (out-of-bounds zero write and hypervisor crash) via unexpected INT 80 processing, because of an incorrect fix for CVE-2017-5754.

An issue was discovered in Xen 4.4.x through 4.9.x allowing ARM guest OS users to cause a denial of service (prevent physical CPU usage) because of lock mishandling upon detection of an add-to-physmap error.

An issue was discovered in Xen through 4.9.x allowing x86 PV guest OS users to cause a denial of service (memory leak) because reference counts are mishandled.

An issue was discovered in Xen through 4.14.x. Nodes in xenstore have an ownership. In oxenstored, a owner could give a node away. However, node ownership has quota implications. Any guest can run another guest out of quota, or create an unbounded number of nodes owned by dom0, thus running xenstored out of memory A malicious guest administrator can cause a denial of service against a specific guest or against the whole host. All systems using oxenstored are vulnerable. Building and using oxenstored is the default in the upstream Xen distribution, if the Ocaml compiler is available. Systems using C xenstored are not vulnerable.

An issue was discovered in Xen through 4.14.x. Xenstored and guests communicate via a shared memory page using a specific protocol. When a guest violates this protocol, xenstored will drop the connection to that guest. Unfortunately, this is done by just removing the guest from xenstored's internal management, resulting in the same actions as if the guest had been destroyed, including sending an @releaseDomain event. @releaseDomain events do not say that the guest has been removed. All watchers of this event must look at the states of all guests to find the guest that has been removed. When an @releaseDomain is generated due to a domain xenstored protocol violation, because the guest is still running, the watchers will not react. Later, when the guest is actually destroyed, xenstored will no longer have it stored in its internal data base, so no further @releaseDomain event will be sent. This can lead to a zombie domain; memory mappings of that guest's memory will not be removed, due to the missing event. This zombie domain will be cleaned up only after another domain is destroyed, as that will trigger another @releaseDomain event. If the device model of the guest that violated the Xenstore protocol is running in a stub-domain, a use-after-free case could happen in xenstored, after having removed the guest from its internal data base, possibly resulting in a crash of xenstored. A malicious guest can block resources of the host for a period after its own death. Guests with a stub domain device model can eventually crash xenstored, resulting in a more serious denial of service (the prevention of any further domain management operations). Only the C variant of Xenstore is affected; the Ocaml variant is not affected. Only HVM guests with a stubdom device model can cause a serious DoS.

Xen through 4.7.x allows local ARM guest OS users to cause a denial of service (host panic) by sending an asynchronous abort.

Xen through 4.7.x allows local ARM guest OS users to cause a denial of service (host crash) via vectors involving an asynchronous abort while at HYP.

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a host OS crash because of incorrect error handling in event-channel port allocation. The allocation of an event-channel port may fail for multiple reasons: (1) port is already in use, (2) the memory allocation failed, or (3) the port we try to allocate is higher than what is supported by the ABI (e.g., 2L or FIFO) used by the guest or the limit set by an administrator (max_event_channels in xl cfg). Due to the missing error checks, only (1) will be considered an error. All the other cases will provide a valid port and will result in a crash when trying to access the event channel. When the administrator configured a guest to allow more than 1023 event channels, that guest may be able to crash the host. When Xen is out-of-memory, allocation of new event channels will result in crashing the host rather than reporting an error. Xen versions 4.10 and later are affected. All architectures are affected. The default configuration, when guests are created with xl/libxl, is not vulnerable, because of the default event-channel limit.

The process_tx_desc function in hw/net/e1000.c in QEMU before 2.4.0.1 does not properly process transmit descriptor data when sending a network packet, which allows attackers to cause a denial of service (infinite loop and guest crash) via unspecified vectors.

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a denial of service because of a bad error path in GNTTABOP_map_grant. Grant table operations are expected to return 0 for success, and a negative number for errors. Some misplaced brackets cause one error path to return 1 instead of a negative value. The grant table code in Linux treats this condition as success, and proceeds with incorrectly initialised state. A buggy or malicious guest can construct its grant table in such a way that, when a backend domain tries to map a grant, it hits the incorrect error path. This will crash a Linux based dom0 or backend domain.

An issue was discovered in Xen through 4.14.x. There is mishandling of the constraint that once-valid event channels may not turn invalid. Logic in the handling of event channel operations in Xen assumes that an event channel, once valid, will not become invalid over the life time of a guest. However, operations like the resetting of all event channels may involve decreasing one of the bounds checked when determining validity. This may lead to bug checks triggering, crashing the host. An unprivileged guest may be able to crash Xen, leading to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only systems with untrusted guests permitted to create more than the default number of event channels are vulnerable. This number depends on the architecture and type of guest. For 32-bit x86 PV guests, this is 1023; for 64-bit x86 PV guests, and for all ARM guests, this number is 4095. Systems where untrusted guests are limited to fewer than this number are not vulnerable. Note that xl and libxl limit max_event_channels to 1023 by default, so systems using exclusively xl, libvirt+libxl, or their own toolstack based on libxl, and not explicitly setting max_event_channels, are not vulnerable.

An issue was discovered in Xen through 4.14.x. An x86 PV guest can trigger a host OS crash when handling guest access to MSR_MISC_ENABLE. When a guest accesses certain Model Specific Registers, Xen first reads the value from hardware to use as the basis for auditing the guest access. For the MISC_ENABLE MSR, which is an Intel specific MSR, this MSR read is performed without error handling for a #GP fault, which is the consequence of trying to read this MSR on non-Intel hardware. A buggy or malicious PV guest administrator can crash Xen, resulting in a host Denial of Service. Only x86 systems are vulnerable. ARM systems are not vulnerable. Only Xen versions 4.11 and onwards are vulnerable. 4.10 and earlier are not vulnerable. Only x86 systems that do not implement the MISC_ENABLE MSR (0x1a0) are vulnerable. AMD and Hygon systems do not implement this MSR and are vulnerable. Intel systems do implement this MSR and are not vulnerable. Other manufacturers have not been checked. Only x86 PV guests can exploit the vulnerability. x86 HVM/PVH guests cannot exploit the vulnerability.

lock order inversion in transitive grant copy handling As part of XSA-226 a missing cleanup call was inserted on an error handling path. While doing so, locking requirements were not paid attention to. As a result two cooperating guests granting each other transitive grants can cause locks to be acquired nested within one another, but in respectively opposite order. With suitable timing between the involved grant copy operations this may result in the locking up of a CPU.

An issue was discovered in Xen through 4.12.x allowing x86 guest OS users to cause a denial of service (infinite loop) because certain bit iteration is mishandled. In a number of places bitmaps are being used by the hypervisor to track certain state. Iteration over all bits involves functions which may misbehave in certain corner cases: On x86 accesses to bitmaps with a compile time known size of 64 may incur undefined behavior, which may in particular result in infinite loops. A malicious guest may cause a hypervisor crash or hang, resulting in a Denial of Service (DoS). All versions of Xen are vulnerable. x86 systems with 64 or more nodes are vulnerable (there might not be any such systems that Xen would run on). x86 systems with less than 64 nodes are not vulnerable.

issues with partially successful P2M updates on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). In some cases the hypervisor carries out the requests by splitting them into smaller chunks. Error handling in certain PoD cases has been insufficient in that in particular partial success of some operations was not properly accounted for. There are two code paths affected - page removal (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix to both issues.)

issues with partially successful P2M updates on x86 T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] x86 HVM and PVH guests may be started in populate-on-demand (PoD) mode, to provide a way for them to later easily have more memory assigned. Guests are permitted to control certain P2M aspects of individual pages via hypercalls. These hypercalls may act on ranges of pages specified via page orders (resulting in a power-of-2 number of pages). In some cases the hypervisor carries out the requests by splitting them into smaller chunks. Error handling in certain PoD cases has been insufficient in that in particular partial success of some operations was not properly accounted for. There are two code paths affected - page removal (CVE-2021-28705) and insertion of new pages (CVE-2021-28709). (We provide one patch which combines the fix to both issues.)

A locally locally exploitable DOS vulnerability was found in pax-linux versions 2.6.32.33-test79.patch, 2.6.38-test3.patch, and 2.6.37.4-test14.patch. A bad bounds check in arch_get_unmapped_area_topdown triggered by programs doing an mmap after a MAP_GROWSDOWN mmap will create an infinite loop condition without releasing the VM semaphore eventually leading to a system crash.

net/ipv4/inet_diag.c in the Linux kernel before 2.6.37-rc2 does not properly audit INET_DIAG bytecode, which allows local users to cause a denial of service (kernel infinite loop) via crafted INET_DIAG_REQ_BYTECODE instructions in a netlink message that contains multiple attribute elements, as demonstrated by INET_DIAG_BC_JMP instructions.

Bad reference counting in the context of accept_ice_connection() in gsm-xsmp-server.c in old versions of gnome-session up until version 2.29.92 allows a local attacker to establish ICE connections to gnome-session with invalid authentication data (an invalid magic cookie). Each failed authentication attempt will leak a file descriptor in gnome-session. When the maximum number of file descriptors is exhausted in the gnome-session process, it will enter an infinite loop trying to communicate without success, consuming 100% of the CPU. The graphical session associated with the gnome-session process will stop working correctly, because communication with gnome-session is no longer possible.

The pcnet_rdra_addr function in hw/net/pcnet.c in QEMU (aka Quick Emulator) allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) by setting the (1) receive or (2) transmit descriptor ring length to 0.

The vmsvga_fifo_run function in hw/display/vmware_vga.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and QEMU process crash) via a VGA command.

The ehci_process_itd function in hw/usb/hcd-ehci.c in QEMU allows local guest OS administrators to cause a denial of service (infinite loop and CPU consumption) via a circular isochronous transfer descriptor (iTD) list.

The fuse_fill_write_pages function in fs/fuse/file.c in the Linux kernel before 4.4 allows local users to cause a denial of service (infinite loop) via a writev system call that triggers a zero length for the first segment of an iov.

In intel_pmu_drain_pebs_nhm in arch/x86/events/intel/ds.c in the Linux kernel through 5.11.8 on some Haswell CPUs, userspace applications (such as perf-fuzzer) can cause a system crash because the PEBS status in a PEBS record is mishandled, aka CID-d88d05a9e0b6.

Denial of Service vulnerability in McAfee Data Loss Prevention (DLP) Endpoint for Windows prior to 11.6.100 allows a local, low privileged, attacker to cause a BSoD through suspending a process, modifying the processes memory and restarting it. This is triggered by the hdlphook driver reading invalid memory.

VMware ESXi (6.7, 6.5, 6.0), Workstation (15.x and 14.x) and Fusion (11.x and 10.x) contain a denial-of-service vulnerability due to an infinite loop in a 3D-rendering shader. Successfully exploiting this issue may allow an attacker with normal user privileges in the guest to make the VM unresponsive, and in some cases, possibly result other VMs on the host or the host itself becoming unresponsive.

The madvise_willneed function in mm/madvise.c in the Linux kernel before 4.14.4 allows local users to cause a denial of service (infinite loop) by triggering use of MADVISE_WILLNEED for a DAX mapping.

An issue was discovered on Samsung mobile devices with L(5.0/5.1), M(6.0), and N(7.x) software. Because of incorrect exception handling for Intents, a local attacker can force a reboot within framework.jar. The Samsung ID is SVE-2017-8390 (May 2017).

Unhandled exception in firmware for Intel(R) Ethernet 700 Series Controllers before version 7.0 may allow an authenticated user to potentially enable a denial of service via local access.

Dell XPS 13 9370 BIOS versions prior to 1.13.1 contains an Improper Exception Handling vulnerability. A local attacker with physical access could exploit this vulnerability to prevent the system from booting until the exploited boot device is removed.

A flaw was found in the Linux kernel's implementation of biovecs in versions before 5.9-rc7. A zero-length biovec request issued by the block subsystem could cause the kernel to enter an infinite loop, causing a denial of service. This flaw allows a local attacker with basic privileges to issue requests to a block device, resulting in a denial of service. The highest threat from this vulnerability is to system availability.

A vulnerability has been identified in LOGO! 12/24RCE (6ED1052-1MD08-0BA1) (All versions), LOGO! 12/24RCEo (6ED1052-2MD08-0BA1) (All versions), LOGO! 230RCE (6ED1052-1FB08-0BA1) (All versions), LOGO! 230RCEo (6ED1052-2FB08-0BA1) (All versions), LOGO! 24CE (6ED1052-1CC08-0BA1) (All versions), LOGO! 24CEo (6ED1052-2CC08-0BA1) (All versions), LOGO! 24RCE (6ED1052-1HB08-0BA1) (All versions), LOGO! 24RCEo (6ED1052-2HB08-0BA1) (All versions), SIPLUS LOGO! 12/24RCE (6AG1052-1MD08-7BA1) (All versions), SIPLUS LOGO! 12/24RCEo (6AG1052-2MD08-7BA1) (All versions), SIPLUS LOGO! 230RCE (6AG1052-1FB08-7BA1) (All versions), SIPLUS LOGO! 230RCEo (6AG1052-2FB08-7BA1) (All versions), SIPLUS LOGO! 24CE (6AG1052-1CC08-7BA1) (All versions), SIPLUS LOGO! 24CEo (6AG1052-2CC08-7BA1) (All versions), SIPLUS LOGO! 24RCE (6AG1052-1HB08-7BA1) (All versions), SIPLUS LOGO! 24RCEo (6AG1052-2HB08-7BA1) (All versions). The control logic (CL) the LOGO! 8 executes could be manipulated in a way that could cause the device executing the CL to improperly handle the manipulation and crash. After successful execution of the attack, the device needs to be manually reset.

In the System UI, there is a possible system crash due to an uncaught exception. This could lead to local permanent denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-11Android ID: A-33646131

In generateCrop of WallpaperManagerService.java, there is a possible sysui crash due to image exceeding maximum texture size. This could lead to local denial of service with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android-8.0 Android-8.1 Android-9 Android-10Android ID: A-120847476

In Threshold::getHistogram of ImageProcessHelper.java, there is a possible crash loop due to an uncaught exception. This could lead to local denial of service with User execution privileges needed. User interaction is needed for exploitation.Product: AndroidVersions: Android-10 Android-8.0 Android-8.1Android ID: A-156087409

A flaw was found in the Linux kernel in the function hid_debug_events_read() in drivers/hid/hid-debug.c file which may enter an infinite loop with certain parameters passed from a userspace. A local privileged user ("root") can cause a system lock up and a denial of service. Versions from v4.18 and newer are vulnerable.

When GNOME Dia before 2019-11-27 is launched with a filename argument that is not a valid codepoint in the current encoding, it enters an endless loop, thus endlessly writing text to stdout. If this launch is from a thumbnailer service, this output will usually be written to disk via the system's logging facility (potentially with elevated privileges), thus filling up the disk and eventually rendering the system unusable. (The filename can be for a nonexistent file.) NOTE: this does not affect an upstream release, but affects certain Linux distribution packages with version numbers such as 0.97.3.