SB2020052041 - Red Hat Enterprise Linux 8.1 Extended Update Support update for kernel
Published: May 20, 2020 Updated: January 24, 2023
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2019-19768)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in the __blk_add_trace() function in kernel/trace/blktrace.c. A local user can run a specially crafted program, trigger a use-after-free error and execute arbitrary code on the system with elevated privileges.
2) NULL pointer dereference (CVE-ID: CVE-2020-10711)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the Linux kernel's SELinux subsystem when importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated.
A remote attacker can send specially crafted packets the affected system, trigger a NULL pointer dereference error and crash the Linux kernel.
3) Race condition (CVE-ID: CVE-2020-11884)
The vulnerability allows a local authenticated user to execute arbitrary code.
In the Linux kernel through 5.6.7 on the s390 platform, code execution may occur because of a race condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur.
Remediation
Install update from vendor's website.