CVE-2018-16882

A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash the host kernel resulting in DoS or potentially gain privileged access to a system. Kernel versions before 4.14.91 and before 4.19.13 are vulnerable.

This kernel update is based on the upstream 4.14.100 and fixes at least the following security issues:

A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash the host kernel resulting in DoS or potentially gain privileged access to a system (CVE-2018-16882).

A flaw was found in the Linux kernel's NFS41+ subsystem. NFS41+ shares mounted in different network namespaces at the same time can make bc_svc_process() use wrong back-channel IDs and cause a use-after-free vulnerability. Thus a malicious container user can cause a host kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out (CVE-2018-16884).

A flaw was found in the Linux kernel in the function hso_probe() which reads if_num value from the USB device (as an u8) and uses it without a length check to index an array, resulting in an OOB memory read in hso_probe() or hso_get_config_data(). An attacker with a forged USB device and physical access to a system (needed to connect such a device) can cause a system crash and a denial of service (CVE-2018-19985).

An issue was discovered in can_can_gw_rcv in net/can/gw.c in the Linux kernel through 4.19.13. The CAN frame modification rules allow bitwise logical operations that can be also applied to the can_dlc field. Because of a missing check, the CAN drivers may write arbitrary content beyond the data registers in the CAN controller's I/O memory when processing can-gw manipulated outgoing frames. This is related to cgw_csum_xor_rel. An unprivileged user can trigger a system crash (general protection fault) (CVE-2019-3701).

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 (CVE-2019-3819).

In the Linux kernel before 4.20.8, kvm_ioctl_create_device in virt/kvm/kvm_main.c mishandles reference counting because of a race condition, leading to a use-after-free (CVE-2019-6974).

A use-after-free vulnerability was found in the way the Linux kernel's KVM hypervisor emulates a preemption timer for L2 guests when nested (=1) virtualization is enabled. This high resolution timer(hrtimer) runs when a L2 guest is active. After VM exit, the sync_vmcs12() timer object is stopped. The use-after-free occurs if the timer object is freed before calling sync_vmcs12() routine. A guest user/process could use this flaw to crash the host kernel resulting in a denial of service or, potentially, gain privileged access to a system (CVE-2019-7221).

An information leakage issue was found in the way Linux kernel's KVM hypervisor handled page fault exceptions while emulating instructions like VMXON, VMCLEAR, VMPTRLD, and VMWRITE with memory address as an operand. It occurs if the operand is a mmio address, as the returned exception object holds uninitialized stack memory contents. A guest user/process could use this flaw to leak host's stack memory contents to a guest (CVE-2019-7222).

Other fixes in this update:

• Ndiswrapper has been updated to 1.62
• WireGuard has been updated to 0.0.20190123

For other uptstream fixes in this update, see the referenced changelogs.

This kernel-linus update is based on the upstream 4.14.100 and fixes at least the following security issues:

Cross-hyperthread Spectre v2 mitigation is now provided by the Single Thread Indirect Branch Predictors (STIBP) support. Note that STIBP also requires the functionality be supported by the Intel microcode in use.

It was found that cephx authentication protocol did not verify ceph clients correctly and was vulnerable to replay attack. Any attacker having access to ceph cluster network who is able to sniff packets on network can use this vulnerability to authenticate with ceph service and perform actions allowed by ceph service (CVE-2018-1128).

A flaw was found in the way signature calculation was handled by cephx authentication protocol. An attacker having access to ceph cluster network who is able to alter the message payload was able to bypass signature checks done by cephx protocol (CVE-2018-1129).

A flaw was found in the Linux Kernel where an attacker may be able to have an uncontrolled read to kernel-memory from within a vm guest. A race condition between connect() and close() function may allow an attacker using the AF_VSOCK protocol to gather a 4 byte information leak or possibly intercept or corrupt AF_VSOCK messages destined to other clients (CVE-2018-14625).

A security flaw was found in the Linux kernel in a way that the cleancache subsystem clears an inode after the final file truncation (removal). The new file created with the same inode may contain leftover pages from cleancache and the old file data instead of the new one (CVE-2018-16862).

A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash the host kernel resulting in DoS or potentially gain privileged access to a system (CVE-2018-16882).

A flaw was found in the Linux kernel's NFS41+ subsystem. NFS41+ shares mounted in different network namespaces at the same time can make bc_svc_process() use wrong back-channel IDs and cause a use-after-free vulnerability. Thus a malicious container user can cause a host kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out (CVE-2018-16884).

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO_ ioctl calls, as demonstrated by allowing local users to write data into holes in a tmpfs file (if the user has read-only access to that file, and that file contains holes) (CVE-2018-18397).

In the Linux kernel through 4.19.6, a local user could exploit a use-after-free in the ALSA driver by supplying a malicious USB Sound device (with zero interfaces) (CVE-2018-19824).

A flaw was found in the Linux kernel in the function hso_probe() which reads if_num value from the USB device (as an u8) and uses it without a length check to index an array, resulting in an OOB memory read in hso_probe() or hso_get_config_data(). An attacker with a forged USB device and physical access to a system (needed to connect such a device) can cause a system crash and a denial of service (CVE-2018-19985).

An issue was discovered in can_can_gw_rcv in net/can/gw.c in the Linux kernel through 4.19.13. The CAN frame modification rules allow bitwise logical operations that can be also applied to the can_dlc field. Because of a missing check, the CAN drivers may write arbitrary content beyond the data registers in the CAN controller's I/O memory when processing can-gw manipulated outgoing frames. This is related to cgw_csum_xor_rel. An unprivileged user can trigger a system crash (general protection fault) (CVE-2019-3701).

A flaw was found in the Linux kernel in the…

This kernel update provides the upstream 4.14.119 that adds the kernel side mitigations for the Microarchitectural Data Sampling (MDS, also called ZombieLoad attack) vulnerabilities in Intel processors that can allow attackers to retrieve data being processed inside a CPU. To complete the mitigations new microcode is also needed, either by installing the microcode-0.20190514-1.mga6 package, or get an updated bios / uefi firmware from the motherboard vendor.

The fixed / mitigated issues are:

Modern Intel microprocessors implement hardware-level micro-optimizations to improve the performance of writing data back to CPU caches. The write operation is split into STA (STore Address) and STD (STore Data) sub-operations. These sub-operations allow the processor to hand-off address generation logic into these sub-operations for optimized writes. Both of these sub-operations write to a shared distributed processor structure called the 'processor store buffer'. As a result, an unprivileged attacker could use this flaw to read private data resident within the CPU's processor store buffer. (CVE-2018-12126)

Microprocessors use a ‘load port’ subcomponent to perform load operations from memory or IO. During a load operation, the load port receives data from the memory or IO subsystem and then provides the data to the CPU registers and operations in the CPU’s pipelines. Stale load operations results are stored in the 'load port' table until overwritten by newer operations. Certain load-port operations triggered by an attacker can be used to reveal data about previous stale requests leaking data back to the attacker via a timing side-channel. (CVE-2018-12127)

A flaw was found in the implementation of the "fill buffer", a mechanism used by modern CPUs when a cache-miss is made on L1 CPU cache. If an attacker can generate a load operation that would create a page fault, the execution will continue speculatively with incorrect data from the fill buffer while the data is fetched from higher level caches. This response time can be measured to infer data in the fill buffer. (CVE-2018-12130)

Uncacheable memory on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. (CVE-2019-11091)

It also fixes at least the following security issues:

Cross-hyperthread Spectre v2 mitigation is now provided by the Single Thread Indirect Branch Predictors (STIBP) support. Note that STIBP also requires the functionality be supported by the Intel microcode in use.

It was found that cephx authentication protocol did not verify ceph clients correctly and was vulnerable to replay attack. Any attacker having access to ceph cluster network who is able to sniff packets on network can use this vulnerability to authenticate with ceph service and perform actions allowed by ceph service (CVE-2018-1128).

A flaw was found in the way signature calculation was handled by cephx authentication protocol. An attacker having access to ceph cluster network who is able to alter the message payload was able to bypass signature checks done by cephx protocol (CVE-2018-1129).

A flaw was found in the Linux Kernel where an attacker may be able to have an uncontrolled read to kernel-memory from within a vm guest. A race condition between connect() and close() function may allow an attacker using the AF_VSOCK protocol to gather a 4 byte information leak or possibly intercept or corrupt AF_VSOCK messages destined to other clients (CVE-2018-14625).

A security flaw was found in the Linux kernel in a way that the cleancache subsystem clears an inode after the final file truncation (removal). The new file created with the same inode may contain leftover pages from cleancache and the old file data instead of the new one (CVE-2018-16862).

A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts when nested(=1) virtualization…

The SUSE Linux Enterprise 12 SP2 LTSS kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• Unprivileged BPF has been disabled by default to reduce attack surface as too many security issues have happened in the past (jsc#SLE-22573)

  You can reenable via systemctl setting /proc/sys/kernel/unprivileged_bpf_disabled to 0. (kernel.unprivileged_bpf_disabled = 0)

• CVE-2017-5753: Systems with microprocessors utilizing speculative execution and branch prediction may have allowed unauthorized disclosure of information to an attacker with local user access via a side-channel analysis (bnc#1068032). Additional spectrev1 fixes were added to the eBPF code.

• CVE-2018-13405: The inode_init_owner function in fs/inode.c allowed local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID (bnc#1087082 bnc#1100416 bnc#1129735).

• CVE-2018-16882: A use-after-free issue was found in the way the KVM hypervisor processed posted interrupts when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash the host kernel resulting in DoS or potentially gain privileged access to a system. Kernel versions and are vulnerable (bnc#1119934).

• CVE-2020-0429: In l2tp_session_delete and related functions of l2tp_core.c, there is possible memory corruption due to a use after free. This could lead to local escalation of privilege with System execution privileges needed. User interaction is not needed for exploitation (bnc#1176724).

• CVE-2020-12655: An issue was discovered in xfs_agf_verify in fs/xfs/libxfs/xfs_alloc.c in the Linux kernel Attackers may trigger a sync of excessive duration via an XFS v5 image with crafted metadata, aka CID-d0c7feaf8767 (bnc#1171217).

• CVE-2020-14305: An out-of-bounds memory write flaw was found in how the Linux kernel’s Voice Over IP H.323 connection tracking functionality handled connections on ipv6 port 1720. This flaw allowed an unauthenticated remote user to crash the system, causing a denial of service. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability (bnc#1173346).

• CVE-2020-3702: Specifically timed and handcrafted traffic can cause internal errors in a WLAN device that lead to improper layer 2 Wi-Fi encryption with a consequent possibility of information disclosure over the air for a discrete set of traffic (bnc#1191193).

• CVE-2021-20265: A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allowed an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability (bnc#1183089).

• CVE-2021-31916: An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel A bound check failure allowed an attacker with special user (CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability (bnc#1192781).

• CVE-2021-33033: The Linux kernel has a use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c because the CIPSO and CALIPSO…

The SUSE Linux Enterprise 12 SP3 LTSS kernel was updated to receive various security and bugfixes.

The following security bugs were fixed:

• Unprivileged BPF has been disabled by default to reduce attack surface as too many security issues have happened in the past (jsc#SLE-22573)

  You can reenable via systemctl setting /proc/sys/kernel/unprivileged_bpf_disabled to 0. (kernel.unprivileged_bpf_disabled = 0)

• CVE-2021-31916: An out-of-bounds (OOB) memory write flaw was found in list_devices in drivers/md/dm-ioctl.c in the Multi-device driver module in the Linux kernel A bound check failure allowed an attacker with special user (CAP_SYS_ADMIN) privilege to gain access to out-of-bounds memory leading to a system crash or a leak of internal kernel information. The highest threat from this vulnerability is to system availability (bnc#1192781).

• CVE-2021-20322: Make the ipv4 and ipv6 ICMP exception caches less predictive to avoid information leaks about UDP ports in use. (bsc#1191790)

• CVE-2021-34981: Fixed file refcounting in cmtp when cmtp_attach_device fails (bsc#1191961).

• CVE-2020-12655: An issue was discovered in xfs_agf_verify in fs/xfs/libxfs/xfs_alloc.c. Attackers may trigger a sync of excessive duration via an XFS v5 image with crafted metadata, aka CID-d0c7feaf8767 (bnc#1171217).

• CVE-2021-43389: There was an array-index-out-of-bounds flaw in the detach_capi_ctr function in drivers/isdn/capi/kcapi.c (bnc#1191958).

• CVE-2021-37159: hso_free_net_device in drivers/net/usb/hso.c called unregister_netdev without checking for the NETREG_REGISTERED state, leading to a use-after-free and a double free (bnc#1188601).

• CVE-2021-34556: An unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because the protection mechanism neglects the possibility of uninitialized memory locations on the BPF stack (bnc#1188983).

• CVE-2021-35477: An unprivileged BPF program can obtain sensitive information from kernel memory via a Speculative Store Bypass side-channel attack because a certain preempting store operation did not necessarily occur before a store operation that has an attacker-controlled value (bnc#1188985).

• CVE-2017-17862: kernel/bpf/verifier.c in the Linux kernel ignores unreachable code, even though it would still be processed by JIT compilers. This behavior, also considered an improper branch-pruning logic issue, could possibly be used by local users for denial of service (bnc#1073928).

• CVE-2017-17864: kernel/bpf/verifier.c in the Linux kernel mishandled states_equal comparisons between the pointer data type and the UNKNOWN_VALUE data type, which allowed local users to obtain potentially sensitive address information, aka a 'pointer leak (bnc#1073928).

• CVE-2021-20265: A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allowed an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability (bnc#1183089).

• CVE-2021-3772: Fixed sctp vtag check in sctp_sf_ootb (bsc#1190351).

• CVE-2021-3655: Missing size validations on inbound SCTP packets may have allowed the kernel to read uninitialized memory (bnc#1188563).

• CVE-2018-13405: The inode_init_owner function in fs/inode.c in the Linux kernel allowed local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID (bnc#1100416 bnc#1129735).

• CVE-2021-3760: Fixed a use-after-free…

Wen Xu discovered that a use-after-free vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10876, CVE-2018-10879)

Wen Xu discovered that a buffer overflow existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10877)

Wen Xu discovered that an out-of-bounds write vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10878, CVE-2018-10882)

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly ensure that xattr information remained in inode bodies. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10880)

Wen Xu discovered that the ext4 file system implementation in the Linux kernel could possibly perform an out of bounds write when updating the journal for an inline file. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10883)

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)

Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. (CVE-2018-17972)

Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when completing, potentially leaving access to a physical page after it has been released to the page allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive information, or possibly execute arbitrary code. (CVE-2018-18281)

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 debug interface for the Linux kernel's HID subsystem did not properly perform bounds checking in some situations. An attacker with access to debugfs could use this to cause a denial of service or possibly gain additional privileges. (CVE-2018-9516)

Wen Xu discovered that a use-after-free vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10876, CVE-2018-10879)

Wen Xu discovered that a buffer overflow existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10877)

Wen Xu discovered that an out-of-bounds write vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10878, CVE-2018-10882)

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly ensure that xattr information remained in inode bodies. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10880)

Wen Xu discovered that the ext4 file system implementation in the Linux kernel could possibly perform an out of bounds write when updating the journal for an inline file. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10883)

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)

Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. (CVE-2018-17972)

Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when completing, potentially leaving access to a physical page after it has been released to the page allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive information, or possibly execute arbitrary code. (CVE-2018-18281)

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 debug interface for the Linux kernel's HID subsystem did not properly perform bounds checking in some situations. An attacker with access to debugfs could use this to cause a denial of service or possibly gain additional privileges. (CVE-2018-9516)

USN-3871-1 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 a use-after-free vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10876, CVE-2018-10879)

Wen Xu discovered that a buffer overflow existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10877)

Wen Xu discovered that an out-of-bounds write vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10878, CVE-2018-10882)

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly ensure that xattr information remained in inode bodies. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10880)

Wen Xu discovered that the ext4 file system implementation in the Linux kernel could possibly perform an out of bounds write when updating the journal for an inline file. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10883)

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)

Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. (CVE-2018-17972)

Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when completing, potentially leaving access to a physical page after it has been released to the page allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive information, or possibly execute arbitrary code. (CVE-2018-18281)

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 debug interface for the Linux kernel's HID subsystem did not properly perform bounds checking in some situations. An attacker with access to debugfs could use this to cause a denial of service or possibly gain additional privileges. (CVE-2018-9516)

Wen Xu discovered that a use-after-free vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10876, CVE-2018-10879)

Wen Xu discovered that a buffer overflow existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10877)

Wen Xu discovered that an out-of-bounds write vulnerability existed in the ext4 filesystem implementation in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10878, CVE-2018-10882)

Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly ensure that xattr information remained in inode bodies. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10880)

Wen Xu discovered that the ext4 file system implementation in the Linux kernel could possibly perform an out of bounds write when updating the journal for an inline file. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a denial of service (system crash). (CVE-2018-10883)

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)

Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. (CVE-2018-17972)

Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when completing, potentially leaving access to a physical page after it has been released to the page allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive information, or possibly execute arbitrary code. (CVE-2018-18281)

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 debug interface for the Linux kernel's HID subsystem did not properly perform bounds checking in some situations. An attacker with access to debugfs could use this to cause a denial of service or possibly gain additional privileges. (CVE-2018-9516)

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)