readykernel-patch-96.21-91.0-1.vl7

An issue was found in the implementation of the coalesced MMIO write operation in KVM. The indices used to access an MMIO ring buffer could be supplied by a user-space process in the host system. An attacker with access to /dev/kvm could use this flaw to trigger out-of-bounds memory access and crash the host kernel or, potentially, escalate their privileges.

It was discovered that a local unprivileged attacker could use a specially crafted sequence of system calls to trigger either a kernel crash in __tcp_retransmit_skb() or use-after-free conditions, which could result in privilege escalation.

It was found that a use-after-free condition could be triggered in the block device subsystem while the outstanding command queue was drained. A patient local attacker can use this flaw to crash the system or, potentially, to escalate their privileges.

It was discovered that a race condition was possible between kmem uncharging and mem_cgroup_reparent_charges(). A kernel warning would be triggered as a result.

A buffer overflow vulnerability was found in the networking virtualization functionality (vhost-net) that could be abused during live migration of virtual machines. A privileged guest user may pass descriptors with invalid length to the host when live migration is underway to crash the host kernel or, potentially, escalate their privileges on the host.

It was found that ucma_leave_multicast() function from 'rdma_ucm' module could try to access a certain data structure after the structure had been freed. This allows an attacker to induce kernel memory corruption, leading to a system crash or other unspecified impact.

It was discovered that a local attacker could exploit mincore() system call to obtain information about memory pages of the running applications from the page cache even if the contents of these memory pages were not available to the attacker.

An attacker, who is able to mount an exported NFS filesystem, is able to trigger a null pointer dereference by using an invalid NFS sequence. This can panic the machine and deny access to the NFS server. Any outstanding disk writes to the NFS server will be lost.

It was discovered that if a file located on Virtuozzo Storage cluster was reopened, the kernel could reuse its mappings without notifying MDS. As a result, if errors were then detected on a CS, for example, caused by power failures, the userspace components would be unable to handle them properly.