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Kernel security update: CVE-2018-1130 and other; Virtuozzo ReadyKernel patch 52.0 for Virtuozzo 7.0.7 HF3

Issue date: 2018-06-01

Applies to: Virtuozzo 7.0

Virtuozzo Advisory ID: VZA-2018-038

1. Overview

The cumulative Virtuozzo ReadyKernel patch was updated with security and stability fixes. The patch applies to the Virtuozzo 7.0 kernel 3.10.0-693.21.1.vz7.48.2 (7.0.7 HF3).

2. Security Fixes

  • [Moderate] Linux kernel before version 4.16-rc7 is vulnerable to a null pointer dereference in dccp_write_xmit() function in net/dccp/output.c in that allows a local user to cause a denial of service by a number of certain crafted system calls. (CVE-2018-1130)

  • [Moderate] It was found that _sctp_make_chunk() function did not check if the chunk length for INIT and INIT_ACK packets was within the allowed limits. A local attacker could exploit this to trigger a kernel crash. (CVE-2018-5803)

  • [Moderate] It was discovered that nfnl_cthelper_list structure was accessible to any user with CAP_NET_ADMIN capability in a network namespace. An unprivileged local user could exploit that to affect netfilter conntrack helpers on the host. (CVE-2017-17448)

  • [Moderate] It was discovered that a nlmon link inside a child network namespace was not restricted to that namespace. An unprivileged local user could exploit that to monitor system-wide netlink activity. (CVE-2017-17449)

  • [Moderate] The KEYS subsystem in the Linux kernel omitted an access-control check when writing a key to the current task’s default keyring, allowing a local user to bypass security checks to the keyring. This compromises the validity of the keyring for those who rely on it. (CVE-2017-17807)

  • [Low] net/netfilter/xt_osf.c in the Linux kernel through 4.14.4 does not require the CAP_NET_ADMIN capability for add_callback and remove_callback operations. This allows local users to bypass intended access restrictions because the xt_osf_fingers data structure is shared across all network namespaces. (CVE-2017-17450)

3. Bug Fixes

  • Potential kernel crash in tcache_detach_page(). (PSBM-81731)

  • If the kernel failed to create an IPv6 socket, for example, due to cgroup.memsw limit, it would crash in ip6mr_sk_done() when trying to clean up multicast routes. (PSBM-83474)

  • It was found that offlined memory cgroups were not destroyed for a long time in some cases. As a result, the system could hit the limit on cgroups (65535) and would be unable to create new ones. (PSBM-83628)

  • Kernel crash in shrink_slab() when trying to mount an image with a broken ext4 file system. (PSBM-83691)

  • It was discovered that the BUG_ON() check in move_freepages() did not verify that the relevant memory pages were valid. The kernel could crash as a result. (PSBM-83746)

  • It was discovered that clone_mnt() did not clear MNT_INTERNAL flag for the internal mounts. As a result, the kernel could crash due to a stack overflow if lots of bind mounts of /proc//ns/ were created in a new namespace. (PSBM-83874)

4. Installing the Update

Download, install, and instantly apply the patch to the current kernel by running ‘readykernel update’.

Dec 12, 2024
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