CVE-2022-2526

The systemd packages contain systemd, a system and service manager for Linux, compatible with the SysV and LSB init scripts. It provides aggressive parallelism capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, and keeps track of processes using Linux cgroups. In addition, it supports snapshotting and restoring of the system state, maintains mount and automount points, and implements an elaborate transactional dependency-based service control logic. It can also work as a drop-in replacement for sysvinit.

Security Fix(es):

• systemd-resolved: use-after-free when dealing with DnsStream in resolved-dns-stream.c (CVE-2022-2526)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

A use-after-free vulnerability was found in systemd. This issue occurs due to the on_stream_io() function and dns_stream_complete() function in 'resolved-dns-stream.c' not incrementing the reference counting for the DnsStream object. Therefore, other functions and callbacks called can dereference the DNSStream object, causing the use-after-free when the reference is still used later.

The systemd packages contain systemd, a system and service manager for Linux, compatible with the SysV and LSB init scripts. It provides aggressive parallelism capabilities, uses socket and D-Bus activation for starting services, offers on-demand starting of daemons, and keeps track of processes using Linux cgroups. In addition, it supports snapshotting and restoring of the system state, maintains mount and automount points, and implements an elaborate transactional dependency-based service control logic. It can also work as a drop-in replacement for sysvinit. Security Fix(es):

• systemd-resolved: use-after-free when dealing with DnsStream in resolved-dns-stream.c (CVE-2022-2526) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

• CVE-2022-2526: use unref the DnsStream in callbacks correctly

• CVE-2022-2526: use unref the DnsStream in callbacks correctly

A use-after-free vulnerability was found in systemd. This issue occurs due to the on_stream_io() function and dns_stream_complete() function in 'resolved-dns-stream.c' not incrementing the reference counting for the DnsStream object. Therefore, other functions and callbacks called can dereference the DNSStream object, causing the use-after-free when the reference is still used later.

It was discovered that systemd incorrectly handled certain DNS requests, which leads to user-after-free vulnerability. An attacker could possibly use this issue to cause a crash or execute arbitrary code. (CVE-2022-2526)

USN-5583-1 fixed vulnerabilities in systemd. Unfortunately this caused a regression by introducing networking problems for some users. This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that systemd incorrectly handled certain DNS requests, which leads to user-after-free vulnerability. An attacker could possibly use this issue to cause a crash or execute arbitrary code. (CVE-2022-2526)