The time_out_leases function in locks.c for Linux kernel before 2.6.15-rc3 allows local users to cause a denial of service (kernel log message consumption) by causing a large number of broken leases, which is recorded to the log using the printk function.

The netlink_rcv_skb function in af_netlink.c in Linux kernel 2.6.14 and 2.6.15 allows local users to cause a denial of service (infinite loop) via a nlmsg_len field of 0.

An issue was discovered in the Linux kernel through 5.11.3, as used with Xen PV. A certain part of the netback driver lacks necessary treatment of errors such as failed memory allocations (as a result of changes to the handling of grant mapping errors). A host OS denial of service may occur during misbehavior of a networking frontend driver. NOTE: this issue exists because of an incomplete fix for CVE-2021-26931.

An issue was discovered in Xen 4.11.x allowing x86 guest OS users to cause a denial of service (host OS hang) because the p2m lock remains unavailable indefinitely in certain error conditions.

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.

ip_nat_pptp in the PPTP NAT helper (netfilter/ip_nat_helper_pptp.c) in Linux kernel 2.6.14, and other versions, allows local users to cause a denial of service (memory corruption or crash) via a crafted outbound packet that causes an incorrect offset to be calculated from pointer arithmetic when non-linear SKBs (socket buffers) are used.

The auto-reap of child processes in Linux kernel 2.6 before 2.6.15 includes processes with ptrace attached, which leads to a dangling ptrace reference and allows local users to cause a denial of service (crash) and gain root privileges.

Linux kernel before 2.6.15 allows local users to cause a denial of service (panic) via a set_mempolicy call with a 0 bitmask, which causes a panic when a page fault occurs.

The collect_mounts function in fs/namespace.c in the Linux kernel before 4.0.5 does not properly consider that it may execute after a path has been unmounted, which allows local users to cause a denial of service (system crash) by leveraging user-namespace root access for an MNT_DETACH umount2 system call.

kvm_pv_send_ipi in arch/x86/kvm/lapic.c in the Linux kernel through 4.19.2 allows local users to cause a denial of service (NULL pointer dereference and BUG) via crafted system calls that reach a situation where the apic map is uninitialized.

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.

The vcpu_scan_ioapic function in arch/x86/kvm/x86.c in the Linux kernel through 4.19.2 allows local users to cause a denial of service (NULL pointer dereference and BUG) via crafted system calls that reach a situation where ioapic is uninitialized.

A certain backport in the TCP Fast Open implementation for the Linux kernel before 3.18 does not properly maintain a count value, which allow local users to cause a denial of service (system crash) via the Fast Open feature, as demonstrated by visiting the chrome://flags/#enable-tcp-fast-open URL when using certain 3.10.x through 3.16.x kernel builds, including longterm-maintenance releases and ckt (aka Canonical Kernel Team) builds.

Memory leak in direct-io.c in Linux kernel 2.6.x before 2.6.10 allows local users to cause a denial of service (memory consumption) via certain O_DIRECT (direct IO) write requests.

The add_del_listener function in kernel/taskstats.c in the Linux kernel 2.6.39.1 and earlier does not prevent multiple registrations of exit handlers, which allows local users to cause a denial of service (memory and CPU consumption), and bypass the OOM Killer, via a crafted application.

The /proc handling (proc/base.c) Linux kernel 2.4 before 2.4.17 allows local users to cause a denial of service via unknown vectors that cause an invalid access of free memory.

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.

The xsave/xrstor implementation in arch/x86/include/asm/xsave.h in the Linux kernel before 3.19.2 creates certain .altinstr_replacement pointers and consequently does not provide any protection against instruction faulting, which allows local users to cause a denial of service (panic) by triggering a fault, as demonstrated by an unaligned memory operand or a non-canonical address memory operand.

long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.

The Linux kernel 4.14.67 mishandles certain interaction among XFRM Netlink messages, IPPROTO_AH packets, and IPPROTO_IP packets, which allows local users to cause a denial of service (memory consumption and system hang) by leveraging root access to execute crafted applications, as demonstrated on CentOS 7.

A flaw was found in the Linux kernel that allows the userspace to call memcpy_fromiovecend() and similar functions with a zero offset and buffer length which causes the read beyond the buffer boundaries, in certain cases causing a memory access fault and a system halt by accessing invalid memory address. This issue only affects kernel version 3.10.x as shipped with Red Hat Enterprise Linux 7.

The tm_reclaim_thread function in arch/powerpc/kernel/process.c in the Linux kernel before 4.4.1 on powerpc platforms does not ensure that TM suspend mode exists before proceeding with a tm_reclaim call, which allows local users to cause a denial of service (TM Bad Thing exception and panic) via a crafted application.

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.

The ELF loader in Linux kernel 2.4 before 2.4.25 allows local users to cause a denial of service (crash) via a crafted ELF file with an interpreter with an invalid arch (architecture), which triggers a BUG() when an invalid VMA is unmapped.

The raw_release function in net/can/raw.c in the Linux kernel before 2.6.39-rc6 does not properly validate a socket data structure, which allows local users to cause a denial of service (NULL pointer dereference) or possibly have unspecified other impact via a crafted release operation.

QEMU, as used in Xen 3.3.x through 4.5.x, does not properly restrict access to PCI command registers, which might allow local HVM guest users to cause a denial of service (non-maskable interrupt and host crash) by disabling the (1) memory or (2) I/O decoding for a PCI Express device and then accessing the device, which triggers an Unsupported Request (UR) response.

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.

ntfs_read_locked_inode in the ntfs.ko filesystem driver in the Linux kernel 4.15.0 allows attackers to trigger a use-after-free read and possibly cause a denial of service (kernel oops or panic) via a crafted ntfs filesystem.

The XEN_DOMCTL_memory_mapping hypercall in Xen 3.2.x through 4.5.x, when using a PCI passthrough device, is not preemptible, which allows local x86 HVM domain users to cause a denial of service (host CPU consumption) via a crafted request to the device model (qemu-dm).

inadequate grant-v2 status frames array bounds check The v2 grant table interface separates grant attributes from grant status. That is, when operating in this mode, a guest has two tables. As a result, guests also need to be able to retrieve the addresses that the new status tracking table can be accessed through. For 32-bit guests on x86, translation of requests has to occur because the interface structure layouts commonly differ between 32- and 64-bit. The translation of the request to obtain the frame numbers of the grant status table involves translating the resulting array of frame numbers. Since the space used to carry out the translation is limited, the translation layer tells the core function the capacity of the array within translation space. Unfortunately the core function then only enforces array bounds to be below 8 times the specified value, and would write past the available space if enough frame numbers needed storing.

Memory leak in drivers/media/video/videobuf-core.c in the videobuf subsystem in the Linux kernel 2.6.x through 4.x allows local users to cause a denial of service (memory consumption) by leveraging /dev/video access for a series of mmap calls that require new allocations, a different vulnerability than CVE-2007-6761. NOTE: as of 2016-06-18, this affects only 11 drivers that have not been updated to use videobuf2 instead of videobuf.

The nft_flush_table function in net/netfilter/nf_tables_api.c in the Linux kernel before 3.18.5 mishandles the interaction between cross-chain jumps and ruleset flushes, which allows local users to cause a denial of service (panic) by leveraging the CAP_NET_ADMIN capability.

Memory leak in the __key_link_end function in security/keys/keyring.c in the Linux kernel before 4.1.4 allows local users to cause a denial of service (memory consumption) via many add_key system calls that refer to existing keys.

HVM soft-reset crashes toolstack libxl requires all data structures passed across its public interface to be initialized before use and disposed of afterwards by calling a specific set of functions. Many internal data structures also require this initialize / dispose discipline, but not all of them. When the "soft reset" feature was implemented, the libxl__domain_suspend_state structure didn't require any initialization or disposal. At some point later, an initialization function was introduced for the structure; but the "soft reset" path wasn't refactored to call the initialization function. When a guest nwo initiates a "soft reboot", uninitialized data structure leads to an assert() when later code finds the structure in an unexpected state. The effect of this is to crash the process monitoring the guest. How this affects the system depends on the structure of the toolstack. For xl, this will have no security-relevant effect: every VM has its own independent monitoring process, which contains no state. The domain in question will hang in a crashed state, but can be destroyed by `xl destroy` just like any other non-cooperating domain. For daemon-based toolstacks linked against libxl, such as libvirt, this will crash the toolstack, losing the state of any in-progress operations (localized DoS), and preventing further administrator operations unless the daemon is configured to restart automatically (system-wide DoS). If crashes "leak" resources, then repeated crashes could use up resources, also causing a system-wide DoS.

The vgic_v2_to_sgi function in arch/arm/vgic-v2.c in Xen 4.5.x, when running on ARM hardware with general interrupt controller (GIC) version 2, allows local guest users to cause a denial of service (host crash) by writing an invalid value to the GICD.SGIR register.

The ext4_zero_range function in fs/ext4/extents.c in the Linux kernel before 4.1 allows local users to cause a denial of service (BUG) via a crafted fallocate zero-range request.

The udf_read_inode function in fs/udf/inode.c in the Linux kernel before 3.18.2 does not ensure a certain data-structure size consistency, which allows local users to cause a denial of service (system crash) via a crafted UDF filesystem image.

The d_walk function in fs/dcache.c in the Linux kernel through 3.17.2 does not properly maintain the semantics of rename_lock, which allows local users to cause a denial of service (deadlock and system hang) via a crafted application.

The rock_continue function in fs/isofs/rock.c in the Linux kernel through 3.18.1 does not restrict the number of Rock Ridge continuation entries, which allows local users to cause a denial of service (infinite loop, and system crash or hang) via a crafted iso9660 image.

The do_double_fault function in arch/x86/kernel/traps.c in the Linux kernel through 3.17.4 does not properly handle faults associated with the Stack Segment (SS) segment register, which allows local users to cause a denial of service (panic) via a modify_ldt system call, as demonstrated by sigreturn_32 in the linux-clock-tests test suite.

The udf_pc_to_char function in fs/udf/symlink.c in the Linux kernel before 3.18.2 relies on component lengths that are unused, which allows local users to cause a denial of service (system crash) via a crafted UDF filesystem image.

The acceleration support for the "REP MOVS" instruction in Xen 4.4.x, 3.2.x, and earlier lacks properly bounds checking for memory mapped I/O (MMIO) emulated in the hypervisor, which allows local HVM guests to cause a denial of service (host crash) via unspecified vectors.