SB2020012303 - Red Hat update for kernel
Published: January 23, 2020
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Race condition (CVE-ID: CVE-2019-11599)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a race condition with mmget_not_zero or get_task_mm calls and is related to fs/userfaultfd.c, mm/mmap.c, fs/proc/task_mmu.c, and drivers/infiniband/core/uverbs_main.c due to kernel does not use locking or other mechanisms to prevent vma layout or vma flags changes while it runs. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.
2) Improper access control (CVE-ID: CVE-2018-18281)
The vulnerability allows a local user to bypass certain security restrictions.
The vulnerability exists due to improper access restrictions to memory when performing TLB flushes after dropping pagetable locks with mremap() syscall, A local user can access a physical page of a stale TLB entry after ftruncate() syscall is called to remove entries from the pagetables of a task that is in the middle of mremap() syscall.
Successful exploitation of the vulnerability may allow an attacker to gain access to sensitive information, stored in process memory.
3) Permissions, privileges, and access controls (CVE-ID: CVE-2018-10853)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists in the way Linux kernel KVM hypervisor emulates instructions, such as sgdt/sidt/fxsave/fxrstor. A local unprivileged user on a guest system can gain write access to kernel space on the same guest system.
Remediation
Install update from vendor's website.