In the Linux kernel before 5.3.12, there is a use-after-free bug that can be caused by a malicious USB device in the drivers/input/ff-memless.c driver, aka CID-fa3a5a1880c9.

relay_open in kernel/relay.c in the Linux kernel through 5.4.1 allows local users to cause a denial of service (such as relay blockage) by triggering a NULL alloc_percpu result.

A memory leak in the af9005_identify_state() function in drivers/media/usb/dvb-usb/af9005.c in the Linux kernel through 5.3.9 allows attackers to cause a denial of service (memory consumption), aka CID-2289adbfa559.

A memory leak in the rtl8xxxu_submit_int_urb() function in drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c in the Linux kernel through 5.3.11 allows attackers to cause a denial of service (memory consumption) by triggering usb_submit_urb() failures, aka CID-a2cdd07488e6.

An issue was discovered in Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a compare-and-exchange operation.

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 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 Xen through 4.12.x allowing Arm domU attackers to cause a denial of service (infinite loop) involving a LoadExcl or StoreExcl operation.

An issue was discovered in Xen 4.8.x through 4.11.x allowing x86 PV guest OS users to cause a denial of service because mishandling of failed IOMMU operations causes a bug check during the cleanup of a crashed guest.

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 the Linux kernel before 5.0.19. There is an out-of-bounds array access in __xfrm_policy_unlink, which will cause denial of service, because verify_newpolicy_info in net/xfrm/xfrm_user.c mishandles directory validation.

An issue was discovered in the Linux kernel before 5.1.8. There is a NULL pointer dereference caused by a malicious USB device in the drivers/usb/misc/sisusbvga/sisusb.c driver.

An issue was discovered in the Linux kernel before 5.2.3. There is a NULL pointer dereference caused by a malicious USB device in the drivers/media/usb/zr364xx/zr364xx.c driver.

An issue was discovered in the Linux kernel before 5.1.8. There is a NULL pointer dereference caused by a malicious USB device in the drivers/media/usb/siano/smsusb.c driver.

check_input_term in sound/usb/mixer.c in the Linux kernel through 5.2.9 mishandles recursion, leading to kernel stack exhaustion.

fs/ecryptfs/inode.c in the eCryptfs subsystem in the Linux kernel before 2.6.28.1 allows local users to cause a denial of service (fault or memory corruption), or possibly have unspecified other impact, via a readlink call that results in an error, leading to use of a -1 return value as an array index.

The evtchn_fifo_set_pending function in Xen 4.4.x allows local guest users to cause a denial of service (host crash) via vectors involving an uninitialized FIFO-based event channel control block when (1) binding or (2) moving an event to a different VCPU.

An issue was discovered in the Linux kernel before 5.2.6. There is a use-after-free caused by a malicious USB device in the drivers/media/usb/cpia2/cpia2_usb.c driver.

An issue was discovered in the Linux kernel before 5.0.14. There is a NULL pointer dereference caused by a malicious USB device in the drivers/usb/misc/yurex.c driver.

An issue was discovered in the Linux kernel before 5.1.17. There is a NULL pointer dereference caused by a malicious USB device in the sound/usb/line6/pcm.c driver.

The x86 segment base write emulation functionality in Xen 4.4.x through 4.7.x allows local x86 PV guest OS administrators to cause a denial of service (host crash) by leveraging lack of canonical address checks.

drivers/net/wireless/ath/ath6kl/usb.c in the Linux kernel through 5.2.9 has a NULL pointer dereference via an incomplete address in an endpoint descriptor.

An issue was discovered in the Linux kernel before 5.1.8. There is a double-free caused by a malicious USB device in the drivers/usb/misc/rio500.c driver.

Memory leak in hw/9pfs/9p-handle.c in QEMU (aka Quick Emulator) allows local privileged guest OS users to cause a denial of service (host memory consumption and possibly QEMU process crash) by leveraging a missing cleanup operation in the handle backend.

drivers/firmware/dell_rbu.c in the Linux kernel before 2.6.27.13, and 2.6.28.x before 2.6.28.2, allows local users to cause a denial of service (system crash) via a read system call that specifies zero bytes from the (1) image_type or (2) packet_size file in /sys/devices/platform/dell_rbu/.

Xen through 4.7.x allows local ARM guest OS users to cause a denial of service (host crash) via vectors involving a (1) data or (2) prefetch abort with the ESR_EL2.EA bit set.

Memory leak in hw/9pfs/9p-proxy.c in QEMU (aka Quick Emulator) allows local privileged guest OS users to cause a denial of service (host memory consumption and possibly QEMU process crash) by leveraging a missing cleanup operation in the proxy backend.

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 EL2.

An issue was discovered in the Linux kernel before 5.2.6. There is a use-after-free caused by a malicious USB device in the drivers/media/v4l2-core/v4l2-dev.c driver because drivers/media/radio/radio-raremono.c does not properly allocate memory.

An issue was discovered in the Linux kernel before 5.2.1. There is a use-after-free caused by a malicious USB device in the drivers/net/wireless/intersil/p54/p54usb.c driver.

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.

A NULL pointer dereference was found in the net/rds/rdma.c __rds_rdma_map() function in the Linux kernel before 4.14.7 allowing local attackers to cause a system panic and a denial-of-service, related to RDS_GET_MR and RDS_GET_MR_FOR_DEST.

In the Linux Kernel before version 4.15.8, 4.14.25, 4.9.87, 4.4.121, 4.1.51, and 3.2.102, an error in the "_sctp_make_chunk()" function (net/sctp/sm_make_chunk.c) when handling SCTP packets length can be exploited to cause a kernel crash.

In Xen 4.10, new infrastructure was introduced as part of an overhaul to how MSR emulation happens for guests. Unfortunately, one tracking structure isn't freed when a vcpu is destroyed. This allows guest OS administrators to cause a denial of service (host OS memory consumption) by rebooting many times.

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.

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 the FUSE filesystem implementation in the Linux kernel before 5.10.6, aka CID-5d069dbe8aaf. fuse_do_getattr() calls make_bad_inode() in inappropriate situations, causing a system crash. NOTE: the original fix for this vulnerability was incomplete, and its incompleteness is tracked as CVE-2021-28950.

In the Linux kernel before 4.17, a local attacker able to set attributes on an xfs filesystem could make this filesystem non-operational until the next mount by triggering an unchecked error condition during an xfs attribute change, because xfs_attr_shortform_addname in fs/xfs/libxfs/xfs_attr.c mishandles ATTR_REPLACE operations with conversion of an attr from short to long form.

An issue was discovered in Xen 4.14.x. When moving IRQs between CPUs to distribute the load of IRQ handling, IRQ vectors are dynamically allocated and de-allocated on the relevant CPUs. De-allocation has to happen when certain constraints are met. If these conditions are not met when first checked, the checking CPU may send an interrupt to itself, in the expectation that this IRQ will be delivered only after the condition preventing the cleanup has cleared. For two specific IRQ vectors, this expectation was violated, resulting in a continuous stream of self-interrupts, which renders the CPU effectively unusable. A domain with a passed through PCI device can cause lockup of a physical CPU, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are vulnerable. Arm systems are not vulnerable. Only guests with physical PCI devices passed through to them can exploit the vulnerability.

An issue was discovered in Xen 4.6 through 4.14.x. When acting upon a guest XS_RESET_WATCHES request, not all tracking information is freed. A guest can cause unbounded memory usage in oxenstored. This can lead to a system-wide DoS. Only systems using the Ocaml Xenstored implementation are vulnerable. Systems using the C Xenstored implementation are not vulnerable.

An issue was discovered in Xen through 4.14.x. When a Xenstore watch fires, the xenstore client that registered the watch will receive a Xenstore message containing the path of the modified Xenstore entry that triggered the watch, and the tag that was specified when registering the watch. Any communication with xenstored is done via Xenstore messages, consisting of a message header and the payload. The payload length is limited to 4096 bytes. Any request to xenstored resulting in a response with a payload longer than 4096 bytes will result in an error. When registering a watch, the payload length limit applies to the combined length of the watched path and the specified tag. Because watches for a specific path are also triggered for all nodes below that path, the payload of a watch event message can be longer than the payload needed to register the watch. A malicious guest that registers a watch using a very large tag (i.e., with a registration operation payload length close to the 4096 byte limit) can cause the generation of watch events with a payload length larger than 4096 bytes, by writing to Xenstore entries below the watched path. This will result in an error condition in xenstored. This error can result in a NULL pointer dereference, leading to a crash of xenstored. A malicious guest administrator can cause xenstored to crash, leading to a denial of service. Following a xenstored crash, domains may continue to run, but management operations will be impossible. Only C xenstored is affected, oxenstored is not affected.

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).

fs/fcntl.c in the "aufs 3.2.x+setfl-debian" patch in the linux-image package 3.2.0-4 (kernel 3.2.81-1) in Debian wheezy mishandles F_SETFL fcntl calls on directories, which allows local users to cause a denial of service (NULL pointer dereference and system crash) via standard filesystem operations, as demonstrated by scp from an AUFS filesystem.

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.

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.

The ehci_advance_state 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 split isochronous transfer descriptor (siTD) list, a related issue to CVE-2015-8558.

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.

An issue was discovered in Xen through 4.14.x. A guest may access xenstore paths via absolute paths containing a full pathname, or via a relative path, which implicitly includes /local/domain/$DOMID for their own domain id. Management tools must access paths in guests' namespaces, necessarily using absolute paths. oxenstored imposes a pathname limit that is applied solely to the relative or absolute path specified by the client. Therefore, a guest can create paths in its own namespace which are too long for management tools to access. Depending on the toolstack in use, a malicious guest administrator might cause some management tools and debugging operations to fail. For example, a guest administrator can cause "xenstore-ls -r" to fail. However, a guest administrator cannot prevent the host administrator from tearing down the domain. 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.