Michael Randrianantenaina discovered that the Bluetooth driver in the Linux Kernel contained an improper access control vulnerability. A nearby attacker could use this to connect a rougue device and possibly execute arbitrary code. (CVE-2024-8805) Attila Szász discovered that the HFS+ file system implementation in the Linux Kernel contained a heap overflow vulnerability. An attacker could use a specially crafted file system image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2025-0927) Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems:

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems:

USN-4225-1 fixed vulnerabilities in the Linux kernel for Ubuntu 19.10. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 19.10 for Ubuntu 18.04 LTS. It was discovered that a heap-based buffer overflow existed in the Marvell WiFi-Ex Driver for the Linux kernel. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-14895, CVE-2019-14901) It was discovered that a heap-based buffer overflow existed in the Marvell Libertas WLAN Driver for the Linux kernel. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-14896, CVE-2019-14897) It was discovered that the Fujitsu ES network device driver for the Linux kernel did not properly check for errors in some situations, leading to a NULL pointer dereference. A local attacker could use this to cause a denial of service. (CVE-2019-16231) Anthony Steinhauser discovered that the Linux kernel did not properly perform SpectreRSB mitigations to all processors for PowerPC architecture systems in some situations. A local attacker could use this to expose sensitive information. (CVE-2019-18660) It was discovered that the Mellanox Technologies Innova driver in the Linux kernel did not properly deallocate memory in certain failure conditions. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19045) It was discovered that the Intel WiMAX 2400 driver in the Linux kernel did not properly deallocate memory in certain situations. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19051) It was discovered that Geschwister Schneider USB CAN interface driver in the Linux kernel did not properly deallocate memory in certain failure conditions. A physically proximate attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19052) It was discovered that the netlink-based 802.11 configuration interface in the Linux kernel did not deallocate memory in certain error conditions. A local attacker could possibly use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19055) It was discovered that the event tracing subsystem of the Linux kernel did not properly deallocate memory in certain error conditions. A local attacker could use this to cause a denial of service (kernel memory exhaustion). (CVE-2019-19072) It was discovered that the driver for memoryless force-feedback input devices in the Linux kernel contained a use-after-free vulnerability. A physically proximate attacker could possibly use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2019-19524) It was discovered that the Microchip CAN BUS Analyzer driver in the Linux kernel contained a use-after-free vulnerability on device disconnect. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-19529) It was discovered that the PEAK-System Technik USB driver in the Linux kernel did not properly sanitize memory before sending it to the device. A physically proximate attacker could use this to expose sensitive information (kernel memory). (CVE-2019-19534) It was discovered that the DesignWare USB3 controller driver in the Linux kernel did not properly deallocate memory in some error conditions. A local attacker could possibly use this to cause a denial of service (memory exhaustion). (CVE-2019-18813)

USN-3358-1 fixed vulnerabilities in the Linux kernel for Ubuntu 17.04. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 17.04 for Ubuntu 16.04 LTS. Please note that this update changes the Linux HWE kernel to the 4.10 based kernel from Ubuntu 17.04, superseding the 4.8 based HWE kernel from Ubuntu 16.10. Ben Harris discovered that the Linux kernel would strip extended privilege attributes of files when performing a failed unprivileged system call. A local attacker could use this to cause a denial of service. (CVE-2015-1350) Ralf Spenneberg discovered that the ext4 implementation in the Linux kernel did not properly validate meta block groups. An attacker with physical access could use this to specially craft an ext4 image that causes a denial of service (system crash). (CVE-2016-10208) Peter Pi discovered that the colormap handling for frame buffer devices in the Linux kernel contained an integer overflow. A local attacker could use this to disclose sensitive information (kernel memory). (CVE-2016-8405) It was discovered that an integer overflow existed in the InfiniBand RDMA over ethernet (RXE) transport implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2016-8636) Vlad Tsyrklevich discovered an integer overflow vulnerability in the VFIO PCI driver for the Linux kernel. A local attacker with access to a vfio PCI device file could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2016-9083, CVE-2016-9084) CAI Qian discovered that the sysctl implementation in the Linux kernel did not properly perform reference counting in some situations. An unprivileged attacker could use this to cause a denial of service (system hang). (CVE-2016-9191) It was discovered that the keyring implementation in the Linux kernel in some situations did not prevent special internal keyrings from being joined by userspace keyrings. A privileged local attacker could use this to bypass module verification. (CVE-2016-9604) Dmitry Vyukov, Andrey Konovalov, Florian Westphal, and Eric Dumazet discovered that the netfiler subsystem in the Linux kernel mishandled IPv6 packet reassembly. A local user could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2016-9755) Andy Lutomirski and Willy Tarreau discovered that the KVM implementation in the Linux kernel did not properly emulate instructions on the SS segment register. A local attacker in a guest virtual machine could use this to cause a denial of service (guest OS crash) or possibly gain administrative privileges in the guest OS. (CVE-2017-2583) Dmitry Vyukov discovered that the KVM implementation in the Linux kernel improperly emulated certain instructions. A local attacker could use this to obtain sensitive information (kernel memory). (CVE-2017-2584) Dmitry Vyukov discovered that KVM implementation in the Linux kernel improperly emulated the VMXON instruction. A local attacker in a guest OS could use this to cause a denial of service (memory consumption) in the host OS. (CVE-2017-2596) It was discovered that SELinux in the Linux kernel did not properly handle empty writes to /proc/pid/attr. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-2618) Daniel Jiang discovered that a race condition existed in the ipv4 ping socket implementation in the Linux kernel. A local privileged attacker could use this to cause a denial of service (system crash). (CVE-2017-2671) It was discovered that the freelist-randomization in the SLAB memory allocator allowed duplicate freelist entries. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-5546) It was discovered that the KLSI KL5KUSB105 serial-to-USB device driver in the Linux kernel did not properly initialize memory related to logging. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2017-5549) It was discovered that a fencepost error existed in the pipeadvance() function in the Linux kernel. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2017-5550) It was discovered that the Linux kernel did not clear the setgid bit during a setxattr call on a tmpfs filesystem. A local attacker could use this to gain elevated group privileges. (CVE-2017-5551) Murray McAllister discovered that an integer overflow existed in the VideoCore DRM driver of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-5576) Gareth Evans discovered that the shm IPC subsystem in the Linux kernel did not properly restrict mapping page zero. A local privileged attacker could use this to execute arbitrary code. (CVE-2017-5669) Andrey Konovalov discovered an out-of-bounds access in the IPv6 Generic Routing Encapsulation (GRE) tunneling implementation in the Linux kernel. An attacker could use this to possibly expose sensitive information. (CVE-2017-5897) Andrey Konovalov discovered that the IPv4 implementation in the Linux kernel did not properly handle invalid IP options in some situations. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2017-5970) Di Shen discovered that a race condition existed in the perf subsystem of the Linux kernel. A local attacker could use this to cause a denial of service or possibly gain administrative privileges. (CVE-2017-6001) Dmitry Vyukov discovered that the Linux kernel did not properly handle TCP packets with the URG flag. A remote attacker could use this to cause a denial of service. (CVE-2017-6214) Andrey Konovalov discovered that the LLC subsytem in the Linux kernel did not properly set up a destructor in certain situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-6345) It was discovered that a race condition existed in the AFPACKET handling code in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-6346) Andrey Konovalov discovered that the IP layer in the Linux kernel made improper assumptions about internal data layout when performing checksums. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-6347) Dmitry Vyukov discovered race conditions in the Infrared (IrDA) subsystem in the Linux kernel. A local attacker could use this to cause a denial of service (deadlock). (CVE-2017-6348) Dmitry Vyukov discovered that the generic SCSI (sg) subsystem in the Linux kernel contained a stack-based buffer overflow. A local attacker with access to an sg device could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-7187) It was discovered that a NULL pointer dereference existed in the Direct Rendering Manager (DRM) driver for VMWare devices in the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-7261) It was discovered that the USB Cypress HID drivers for the Linux kernel did not properly validate reported information from the device. An attacker with physical access could use this to expose sensitive information (kernel memory). (CVE-2017-7273) Eric Biggers discovered a memory leak in the keyring implementation in the Linux kernel. A local attacker could use this to cause a denial of service (memory consumption). (CVE-2017-7472) It was discovered that an information leak existed in the setmempolicy and mbind compat syscalls in the Linux kernel. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2017-7616) Sabrina Dubroca discovered that the asynchronous cryptographic hash (ahash) implementation in the Linux kernel did not properly handle a full request queue. A local attacker could use this to cause a denial of service (infinite recursion). (CVE-2017-7618) Tuomas Haanpää and Ari Kauppi discovered that the NFSv2 and NFSv3 server implementations in the Linux kernel did not properly handle certain long RPC replies. A remote attacker could use this to cause a denial of service (system crash). (CVE-2017-7645) Tommi Rantala and Brad Spengler discovered that the memory manager in the Linux kernel did not properly enforce the CONFIGSTRICTDEVMEM protection mechanism. A local attacker with access to /dev/mem could use this to expose sensitive information or possibly execute arbitrary code. (CVE-2017-7889) Tuomas Haanpää and Ari Kauppi discovered that the NFSv2 and NFSv3 server implementations in the Linux kernel did not properly check for the end of buffer. A remote attacker could use this to craft requests that cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-7895) It was discovered that an integer underflow existed in the Edgeport USB Serial Converter device driver of the Linux kernel. An attacker with physical access could use this to expose sensitive information (kernel memory). (CVE-2017-8924) It was discovered that the USB ZyXEL omni.net LCD PLUS driver in the Linux kernel did not properly perform reference counting. A local attacker could use this to cause a denial of service (tty exhaustion). (CVE-2017-8925) Jann Horn discovered that bpf in Linux kernel does not restrict the output of the printbpfinsn function. A local attacker could use this to obtain sensitive address information. (CVE-2017-9150)

USN-3695-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS. Wen Xu discovered that the ext4 file system implementation in the Linux kernel did not properly initialize the crc32c checksum driver. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1094) It was discovered that the cdrom driver in the Linux kernel contained an incorrect bounds check. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-10940) Wen Xu discovered that the ext4 file system implementation in the Linux kernel did not properly validate xattr sizes. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-1095) Jann Horn discovered that the 32 bit adjtimex() syscall implementation for 64 bit Linux kernels did not properly initialize memory returned to user space in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-11508) It was discovered that an information leak vulnerability existed in the floppy driver in the Linux kernel. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-7755)

USN-3653-1 fixed vulnerabilities and added mitigations in the Linux kernel for Ubuntu 17.10. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 17.10 for Ubuntu 16.04 LTS. Jann Horn and Ken Johnson discovered that microprocessors utilizing speculative execution of a memory read may allow unauthorized memory reads via a sidechannel attack. This flaw is known as Spectre Variant 4. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2018-3639) It was discovered that the netlink subsystem in the Linux kernel did not properly restrict observations of netlink messages to the appropriate net namespace. A local attacker could use this to expose sensitive information (kernel netlink traffic). (CVE-2017-17449) Tuba Yavuz discovered that a double-free error existed in the USBTV007 driver of the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2017-17975) It was discovered that a race condition existed in the Device Mapper component of the Linux kernel. A local attacker could use this to cause a denial of service (system crash). (CVE-2017-18203) It was discovered that an infinite loop could occur in the madvise(2) implementation in the Linux kernel in certain circumstances. A local attacker could use this to cause a denial of service (system hang). (CVE-2017-18208) Silvio Cesare discovered a buffer overwrite existed in the NCPFS implementation in the Linux kernel. A remote attacker controlling a malicious NCPFS server could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-8822)

USN-3630-1 fixed a vulnerability in the Linux kernel for Ubuntu 17.10. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 17.10 for Ubuntu 16.04 LTS. It was discovered that the Broadcom UniMAC MDIO bus controller driver in the Linux kernel did not properly validate device resources. A local attacker could use this to cause a denial of service (system crash).

USN-3541-1 addressed vulnerabilities in the Linux kernel for Ubuntu 17.10. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 17.10 for Ubuntu 16.04 LTS. Jann Horn discovered that microprocessors utilizing speculative execution and branch prediction may allow unauthorized memory reads via sidechannel attacks. This flaw is known as Spectre. A local attacker could use this to expose sensitive information, including kernel memory. This update provides mitigations for the i386 (CVE-2017-5753 only), amd64, ppc64el, and s390x architectures. (CVE-2017-5715, CVE-2017-5753) USN-3523-2 mitigated CVE-2017-5754 (Meltdown) for the amd64 architecture in the Linux Hardware Enablement (HWE) kernel from Ubuntu 17.10 for Ubuntu 16.04 LTS. This update provides the corresponding mitigations for the ppc64el architecture. Original advisory details: Jann Horn discovered that microprocessors utilizing speculative execution and indirect branch prediction may allow unauthorized memory reads via sidechannel attacks. This flaw is known as Meltdown. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2017-5754)

It was discovered that a race condition existed in the vsock address family implementation of the Linux kernel that could lead to a use-after-free condition. A local attacker in a guest virtual machine could use this to expose sensitive information (host machine kernel memory). (CVE-2018-14625) Cfir Cohen discovered that a use-after-free vulnerability existed in the KVM implementation of the Linux kernel, when handling interrupts in environments where nested virtualization is in use (nested KVM virtualization is not enabled by default in Ubuntu kernels). A local attacker in a guest VM could possibly use this to gain administrative privileges in a host machine. (CVE-2018-16882) Wei Wu discovered that the KVM implementation in the Linux kernel did not properly ensure that ioapics were initialized. A local attacker could use this to cause a denial of service (system crash). (CVE-2018-19407) It was discovered that the crypto subsystem of the Linux kernel leaked uninitialized memory to user space in some situations. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2018-19854)

USN-4007-1 fixed vulnerabilities in the Linux kernel for Ubuntu 18.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 18.04 LTS for Ubuntu 16.04 LTS. Federico Manuel Bento discovered that the Linux kernel did not properly apply Address Space Layout Randomization (ASLR) in some situations for setuid a.out binaries. A local attacker could use this to improve the chances of exploiting an existing vulnerability in a setuid a.out binary. As a hardening measure, this update disables a.out support.

USN-4157-1 fixed vulnerabilities in the Linux kernel for Ubuntu 19.04. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 19.04 for Ubuntu 18.04 LTS. Wen Huang discovered that the Marvell Wi-Fi device driver in the Linux kernel did not properly perform bounds checking, leading to a heap overflow. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2019-14814, CVE-2019-14815, CVE-2019-14816) Matt Delco discovered that the KVM hypervisor implementation in the Linux kernel did not properly perform bounds checking when handling coalesced MMIO write operations. A local attacker with write access to /dev/kvm could use this to cause a denial of service (system crash). (CVE-2019-14821) Hui Peng and Mathias Payer discovered that the 91x Wi-Fi driver in the Linux kernel did not properly handle error conditions on initialization, leading to a double-free vulnerability. A physically proximate attacker could use this to cause a denial of service (system crash). (CVE-2019-15504) It was discovered that the Technisat DVB-S/S2 USB device driver in the Linux kernel contained a buffer overread. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information. (CVE-2019-15505) Brad Spengler discovered that a Spectre mitigation was improperly implemented in the ptrace susbsystem of the Linux kernel. A local attacker could possibly use this to expose sensitive information. (CVE-2019-15902) It was discovered that the IPv6 RDS implementation in the Linux kernel did not properly initialize fields in a data structure returned to user space. A local attacker could use this to expose sensitive information (kernel memory). Please note that the RDS protocol is disabled via blocklist in Ubuntu by default. (CVE-2019-16714) It was discovered that an integer overflow existed in the Binder implementation of the Linux kernel, leading to a buffer overflow. A local attacker could use this to escalate privileges. (CVE-2019-2181)

Kyle Zeng discovered that the sysctl implementation in the Linux kernel contained a stack-based buffer overflow. A local attacker could use this to cause a denial of service (system crash) or execute arbitrary code. (CVE-2022-4378) It was discovered that an out-of-bounds write vulnerability existed in the Video for Linux 2 (V4L2) implementation in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2022-20369) Pawan Kumar Gupta, Alyssa Milburn, Amit Peled, Shani Rehana, Nir Shildan and Ariel Sabba discovered that some Intel processors with Enhanced Indirect Branch Restricted Speculation (eIBRS) did not properly handle RET instructions after a VM exits. A local attacker could potentially use this to expose sensitive information. (CVE-2022-26373) David Leadbeater discovered that the netfilter IRC protocol tracking implementation in the Linux Kernel incorrectly handled certain message payloads in some situations. A remote attacker could possibly use this to cause a denial of service or bypass firewall filtering. (CVE-2022-2663) Johannes Wikner and Kaveh Razavi discovered that for some AMD x86-64 processors, the branch predictor could by mis-trained for return instructions in certain circumstances. A local attacker could possibly use this to expose sensitive information. (CVE-2022-29900) Johannes Wikner and Kaveh Razavi discovered that for some Intel x86-64 processors, the Linux kernel's protections against speculative branch target injection attacks were insufficient in some circumstances. A local attacker could possibly use this to expose sensitive information. (CVE-2022-29901) It was discovered that a race condition existed in the Kernel Connection Multiplexor (KCM) socket implementation in the Linux kernel when releasing sockets in certain situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2022-3521) It was discovered that the Netronome Ethernet driver in the Linux kernel contained a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2022-3545) It was discovered that the Broadcom FullMAC USB WiFi driver in the Linux kernel did not properly perform bounds checking in some situations. A physically proximate attacker could use this to craft a malicious USB device that when inserted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2022-3628) It was discovered that a use-after-free vulnerability existed in the Bluetooth stack in the Linux kernel. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2022-3640) It was discovered that the NILFS2 file system implementation in the Linux kernel did not properly deallocate memory in certain error conditions. An attacker could use this to cause a denial of service (memory exhaustion). (CVE-2022-3646) Khalid Masum discovered that the NILFS2 file system implementation in the Linux kernel did not properly handle certain error conditions, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2022-3649) Hyunwoo Kim discovered that an integer overflow vulnerability existed in the PXA3xx graphics driver in the Linux kernel. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2022-39842) It was discovered that a race condition existed in the SMSC UFX USB driver implementation in the Linux kernel, leading to a use-after-free vulnerability. A physically proximate attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2022-41849) It was discovered that a race condition existed in the Roccat HID driver in the Linux kernel, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2022-41850) It was discovered that a race condition existed in the Xen network backend driver in the Linux kernel when handling dropped packets in certain circumstances. An attacker could use this to cause a denial of service (kernel deadlock). (CVE-2022-42328) Tamás Koczka discovered that the Bluetooth L2CAP implementation in the Linux kernel did not properly initialize memory in some situations. A physically proximate attacker could possibly use this to expose sensitive information (kernel memory). (CVE-2022-42895) It was discovered that the USB monitoring (usbmon) component in the Linux kernel did not properly set permissions on memory mapped in to user space processes. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2022-43750) It was discovered that the Upper Level Protocol (ULP) subsystem in the Linux kernel did not properly handle sockets entering the LISTEN state in certain protocols, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2023-0461)

USN-5071-1 fixed vulnerabilities in the Linux kernel for Ubuntu 20.04 LTS. This update provides the corresponding updates for the Linux Hardware Enablement (HWE) kernel from Ubuntu 20.04 LTS for Ubuntu 18.04 LTS. Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel allowed a guest VM to disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a guest VM could use this to read or write portions of the host's physical memory. (CVE-2021-3656) Maxim Levitsky discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not properly prevent a guest VM from enabling AVIC in nested guest VMs. An attacker in a guest VM could use this to write to portions of the host's physical memory. (CVE-2021-3653) It was discovered that the KVM hypervisor implementation for AMD processors in the Linux kernel did not ensure enough processing time was given to perform cleanups of large SEV VMs. A local attacker could use this to cause a denial of service (soft lockup). (CVE-2020-36311) It was discovered that the KVM hypervisor implementation in the Linux kernel did not properly perform reference counting in some situations, leading to a use-after-free vulnerability. An attacker who could start and control a VM could possibly use this to expose sensitive information or execute arbitrary code. (CVE-2021-22543) Murray McAllister discovered that the joystick device interface in the Linux kernel did not properly validate data passed via an ioctl(). A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code on systems with a joystick device registered. (CVE-2021-3612)