Kernel update: Virtuozzo ReadyKernel patch 77.1 for Virtuozzo 7.0.7 HF2 to 7.0.8 HF1

Issue date: 2019-04-25

Applies to: Virtuozzo 7.0

Virtuozzo Advisory ID: VZA-2019-031

1. Overview

The cumulative Virtuozzo ReadyKernel patch was updated with stability fixes. The patch applies to Virtuozzo kernels 3.10.0-693.21.1.vz7.46.7 (Virtuozzo 7.0.7 HF2), 3.10.0-693.21.1.vz7.48.2 (Virtuozzo 7.0.7 HF3), 3.10.0-862.9.1.vz7.63.3 (Virtuozzo 7.0.8), and 3.10.0-862.11.6.vz7.64.7 (Virtuozzo 7.0.8 HF1).

2. Bug Fixes

  • If some process held the CPU cgroup of a container while the container was being stopped, the kernel would try to add this cgroup to the list of such structures again when the container was started the next time. This would corrupt the list, and calc_load_ve() function would go in an endless loop as a result. (PSBM-88251)

  • ploop: potential data corruption due to a race between ‘prepare_merge’ and ‘submit_alloc’ operations. (PSBM-93349)

  • High order page allocations were triggered by CRIU while restoring TCP sockets. (PSBM-93672)

  • High order page allocations were made in neigh_probe() in certain cases. (PSBM-93713)

  • It was discovered that network drivers could allocate memory for the socket buffers from pfmemalloc memory reserves, even when it was unnecessary. As a result, the network packets were dropped by sk_filter_trim_cap() causing performance issues. (VSTOR-21390)

3. Installing the Update

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