SB2021072789 - SUSE update for the Linux Kernel (Live Patch 36 for SLE 12 SP3)

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Use-after-free (CVE-ID: CVE-2020-36385)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error in drivers/infiniband/core/ucma.c, because the ctx is reached via the ctx_list in some ucma_migrate_id situations where ucma_close is called. A local user can run a specially crafted program to trigger the use-after-free error and execute arbitrary code with elevated privileges.

2) Out-of-bounds write (CVE-ID: CVE-2021-22555)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error when processing untrusted input in net/netfilter/x_tables.c in Linux kernel. A local user can run a specially crafted program to trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

3) Integer overflow (CVE-ID: CVE-2021-33909)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to integer overflow during size_t-to-int conversion when creating, mounting, and deleting a deep directory structure whose total path length exceeds 1GB. An unprivileged local user can write up to 10-byte string to an offset of exactly -2GB-10B below the beginning of a vmalloc()ated kernel buffer.

Successful exploitation of vulnerability may allow an attacker to exploit the our-of-bounds write vulnerability to execute arbitrary code with root privileges.

Remediation

Install update from vendor's website.

References

• https://www.suse.com/support/update/announcement/2021/suse-su-20212538-1/