SB2021101272 - SUSE update for the Linux Kernel (Live Patch 0 for SLE 15 SP3)

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Incorrect calculation (CVE-ID: CVE-2021-31440)

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

The vulnerability exists due to out-of-bounds access flaw in the Linux kernel’s implementation of the eBPF code verifier, where an incorrect register bounds calculation while checking unsigned 32-bit instructions in an eBPF program occurs. A local user can use this flaw to crash the system or possibly escalate their privileges on the system.

2) Use-after-free (CVE-ID: CVE-2021-3573)

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

The vulnerability exists due to a use-after-free in hci_sock_bound_ioctl() function of the Linux kernel HCI subsystem triggers race condition of the call hci_unregister_dev() together with one of the calls hci_sock_blacklist_add(), hci_sock_blacklist_del(), hci_get_conn_info(), hci_get_auth_info(). A privileged local user can use this flaw to crash the system or escalate privileges on the system.

3) Use-after-free (CVE-ID: CVE-2021-3640)

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

The vulnerability exists due to a use-after-free error in sco_sock_sendmsg() function of the Linux kernel HCI subsystem. A privileged local user can call ioct UFFDIO_REGISTER or other way trigger race condition to escalate privileges on the system.

Remediation

Install update from vendor's website.

References

• https://www.suse.com/support/update/announcement/2021/suse-su-20213360-1/