KVM in the Linux kernel on Power8 processors has a conflicting use of HSTATE_HOST_R1 to store r1 state in kvmppc_hv_entry plus in kvmppc_{save,restore}_tm, leading to a stack corruption. Because of this, an attacker with the ability run code in kernel space of a guest VM can cause the host kernel to panic. There were two commits that, according to the reporter, introduced the vulnerability: f024ee098476 ("KVM: PPC: Book3S HV: Pull out TM state save/restore into separate procedures") 87a11bb6a7f7 ("KVM: PPC: Book3S HV: Work around XER[SO] bug in fake suspend mode") The former landed in 4.8, the latter in 4.17. This was fixed without realizing the impact in 4.18 with the following three commits, though it's believed the first is the only strictly necessary commit: 6f597c6b63b6 ("KVM: PPC: Book3S PR: Add guest MSR parameter for kvmppc_save_tm()/kvmppc_restore_tm()") 7b0e827c6970 ("KVM: PPC: Book3S HV: Factor fake-suspend handling out of kvmppc_save/restore_tm") 009c872a8bc4 ("KVM: PPC: Book3S PR: Move kvmppc_save_tm/kvmppc_restore_tm to separate file")

net/sctp/sm_sideeffect.c in the Linux kernel before 4.3 does not properly manage the relationship between a lock and a socket, which allows local users to cause a denial of service (deadlock) via a crafted sctp_accept call.

The keyctl_read_key function in security/keys/keyctl.c in the Linux kernel before 4.3.4 does not properly use a semaphore, which allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via a crafted application that leverages a race condition between keyctl_revoke and keyctl_read calls.

Race condition in net/sctp/socket.c in the Linux kernel before 4.1.2 allows local users to cause a denial of service (list corruption and panic) via a rapid series of system calls related to sockets, as demonstrated by setsockopt calls.

It was found that the net_dma code in tcp_recvmsg() in the 2.6.32 kernel as shipped in RHEL6 is thread-unsafe. So an unprivileged multi-threaded userspace application calling recvmsg() for the same network socket in parallel executed on ioatdma-enabled hardware with net_dma enabled can leak the memory, crash the host leading to a denial-of-service or cause a random memory corruption.

A use-after-free vulnerability was found in network namespaces code affecting the Linux kernel before 4.14.11. The function get_net_ns_by_id() in net/core/net_namespace.c does not check for the net::count value after it has found a peer network in netns_ids idr, which could lead to double free and memory corruption. This vulnerability could allow an unprivileged local user to induce kernel memory corruption on the system, leading to a crash. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although it is thought to be unlikely.

Race condition in arch/x86/kvm/x86.c in the Linux kernel before 2.6.38 allows L2 guest OS users to cause a denial of service (L1 guest OS crash) via a crafted instruction that triggers an L2 emulation failure report, a similar issue to CVE-2014-7842.

Race condition in arch/x86/kvm/x86.c in the Linux kernel before 3.17.4 allows guest OS users to cause a denial of service (guest OS crash) via a crafted application that performs an MMIO transaction or a PIO transaction to trigger a guest userspace emulation error report, a similar issue to CVE-2010-5313.

include/linux/init_task.h in the Linux kernel before 2.6.35 does not prevent signals with a process group ID of zero from reaching the swapper process, which allows local users to cause a denial of service (system crash) by leveraging access to this process group.

net/ipv6/tcp_ipv6.c in Linux kernel 2.6.x up to 2.6.21-rc3 inadvertently copies the ipv6_fl_socklist from a listening TCP socket to child sockets, which allows local users to cause a denial of service (OOPS) or double free by opening a listening IPv6 socket, attaching a flow label, and connecting to that socket.

nfnetlink_log in netfilter in the Linux kernel before 2.6.20.3 allows attackers to cause a denial of service (crash) via unspecified vectors involving the (1) nfulnl_recv_config function, (2) using "multiple packets per netlink message", and (3) bridged packets, which trigger a NULL pointer dereference.

The NFSv4 implementation in the Linux kernel through 4.11.1 allows local users to cause a denial of service (resource consumption) by leveraging improper channel callback shutdown when unmounting an NFSv4 filesystem, aka a "module reference and kernel daemon" leak.

The ip6_sk_dst_check function in net/ipv6/ip6_output.c in the Linux kernel before 3.10 allows local users to cause a denial of service (system crash) by using an AF_INET6 socket for a connection to an IPv4 interface.

The smbhash function in fs/cifs/smbencrypt.c in the Linux kernel 4.9.x before 4.9.1 interacts incorrectly with the CONFIG_VMAP_STACK option, which allows local users to cause a denial of service (system crash or memory corruption) or possibly have unspecified other impact by leveraging use of more than one virtual page for a scatterlist.

The nested_vmx_check_vmptr function in arch/x86/kvm/vmx.c in the Linux kernel through 4.9.8 improperly emulates the VMXON instruction, which allows KVM L1 guest OS users to cause a denial of service (host OS memory consumption) by leveraging the mishandling of page references.

The sys_timer_create function in posix-timers.c for Linux kernel 2.6.x allows local users to cause a denial of service (memory consumption) and possibly bypass memory limits or cause other processes to be killed by creating a large number of posix timers, which are allocated in kernel memory but are not treated as part of the process' memory.

The vc4_get_bcl function in drivers/gpu/drm/vc4/vc4_gem.c in the VideoCore DRM driver in the Linux kernel before 4.9.7 does not set an errno value upon certain overflow detections, which allows local users to cause a denial of service (incorrect pointer dereference and OOPS) via inconsistent size values in a VC4_SUBMIT_CL ioctl call.

The rngapi_reset function in crypto/rng.c in the Linux kernel before 4.2 allows attackers to cause a denial of service (NULL pointer dereference).

The keyctl_read_key function in security/keys/keyctl.c in the Key Management subcomponent in the Linux kernel before 4.13.5 does not properly consider that a key may be possessed but negatively instantiated, which allows local users to cause a denial of service (OOPS and system crash) via a crafted KEYCTL_READ operation.

security/keys/keyctl.c in the Linux kernel before 4.11.5 does not consider the case of a NULL payload in conjunction with a nonzero length value, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) via a crafted add_key or keyctl system call, a different vulnerability than CVE-2017-12192.

The tcp_read_sock function in net/ipv4/tcp.c in the Linux kernel before 2.6.34 does not properly manage skb consumption, which allows local users to cause a denial of service (system crash) via a crafted splice system call for a TCP socket.

The x86_decode_insn function in arch/x86/kvm/emulate.c in the Linux kernel before 4.8.7, when KVM is enabled, allows local users to cause a denial of service (host OS crash) via a certain use of a ModR/M byte in an undefined instruction.

The cgroup offline implementation in the Linux kernel through 4.8.11 mishandles certain drain operations, which allows local users to cause a denial of service (system hang) by leveraging access to a container environment for executing a crafted application, as demonstrated by trinity.

The hash_accept function in crypto/algif_hash.c in the Linux kernel before 4.3.6 allows local users to cause a denial of service (OOPS) by attempting to trigger use of in-kernel hash algorithms for a socket that has received zero bytes of data.

The tcp_check_send_head function in include/net/tcp.h in the Linux kernel before 4.7.5 does not properly maintain certain SACK state after a failed data copy, which allows local users to cause a denial of service (tcp_xmit_retransmit_queue use-after-free and system crash) via a crafted SACK option.

fs/overlayfs/dir.c in the OverlayFS filesystem implementation in the Linux kernel before 4.6 does not properly verify the upper dentry before proceeding with unlink and rename system-call processing, which allows local users to cause a denial of service (system crash) via a rename system call that specifies a self-hardlink.

An issue was discovered in drivers/usb/gadget/composite.c in the Linux kernel before 5.16.10. The USB Gadget subsystem lacks certain validation of interface OS descriptor requests (ones with a large array index and ones associated with NULL function pointer retrieval). Memory corruption might occur.

fs/pnode.c in the Linux kernel before 4.5.4 does not properly traverse a mount propagation tree in a certain case involving a slave mount, which allows local users to cause a denial of service (NULL pointer dereference and OOPS) via a crafted series of mount system calls.

The ims_pcu_parse_cdc_data function in drivers/input/misc/ims-pcu.c in the Linux kernel before 4.5.1 allows physically proximate attackers to cause a denial of service (system crash) via a USB device without both a master and a slave interface.

drivers/usb/serial/cypress_m8.c in the Linux kernel before 4.5.1 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) via a USB device without both an interrupt-in and an interrupt-out endpoint descriptor, related to the cypress_generic_port_probe and cypress_open functions.

The create_fixed_stream_quirk function in sound/usb/quirks.c in the snd-usb-audio driver in the Linux kernel before 4.5.1 allows physically proximate attackers to cause a denial of service (NULL pointer dereference or double free, and system crash) via a crafted endpoints value in a USB device descriptor.

sound/core/timer.c in the Linux kernel before 4.4.1 retains certain linked lists after a close or stop action, which allows local users to cause a denial of service (system crash) via a crafted ioctl call, related to the (1) snd_timer_close and (2) _snd_timer_stop functions.

The acm_probe function in drivers/usb/class/cdc-acm.c in the Linux kernel before 4.5.1 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) via a USB device without both a control and a data endpoint descriptor.

The ati_remote2_probe function in drivers/input/misc/ati_remote2.c in the Linux kernel before 4.5.1 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) via a crafted endpoints value in a USB device descriptor.

The iowarrior_probe function in drivers/usb/misc/iowarrior.c in the Linux kernel before 4.5.1 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) via a crafted endpoints value in a USB device descriptor.

The __skb_recv_datagram function in net/core/datagram.c in the Linux kernel before 3.8 does not properly handle the MSG_PEEK flag with zero-length data, which allows local users to cause a denial of service (infinite loop and system hang) via a crafted application.

The mct_u232_msr_to_state function in drivers/usb/serial/mct_u232.c in the Linux kernel before 4.5.1 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) via a crafted USB device without two interrupt-in endpoint descriptors.

The gtco_probe function in drivers/input/tablet/gtco.c in the Linux kernel through 4.5.2 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) via a crafted endpoints value in a USB device descriptor.

The treo_attach function in drivers/usb/serial/visor.c in the Linux kernel before 4.5 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact by inserting a USB device that lacks a (1) bulk-in or (2) interrupt-in endpoint.

The wacom_probe function in drivers/input/tablet/wacom_sys.c in the Linux kernel before 3.17 allows physically proximate attackers to cause a denial of service (NULL pointer dereference and system crash) via a crafted endpoints value in a USB device descriptor.

An issue was discovered in the Linux kernel through 4.17.2. Since the page allocator does not yield CPU resources to the owner of the oom_lock mutex, a local unprivileged user can trivially lock up the system forever by wasting CPU resources from the page allocator (e.g., via concurrent page fault events) when the global OOM killer is invoked. NOTE: the software maintainer has not accepted certain proposed patches, in part because of a viewpoint that "the underlying problem is non-trivial to handle.

Linux kernel before 2.6.18, when running on x86_64 systems, does not properly save or restore EFLAGS during a context switch, which allows local users to cause a denial of service (crash) by causing SYSENTER to set an NT flag, which can trigger a crash on the IRET of the next task.

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.

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.

fs/overlayfs/copy_up.c in the Linux kernel before 4.2.6 uses an incorrect cleanup code path, which allows local users to cause a denial of service (dentry reference leak) via filesystem operations on a large file in a lower overlayfs layer.

The xen_failsafe_callback function in Xen for the Linux kernel 2.6.23 and other versions, when running a 32-bit PVOPS guest, allows local users to cause a denial of service (guest crash) by triggering an iret fault, leading to use of an incorrect stack pointer and stack corruption.