Ubuntu 20.04 LTS / 22.04 LTS : Linux kernel vulnerabilities (USN-5667-1)


The remote Ubuntu 20.04 LTS / 22.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-5667-1 advisory. - A use-after-free flaw was found in the Linux kernel's pipes functionality in how a user performs manipulations with the pipe post_one_notification() after free_pipe_info() that is already called. This flaw allows a local user to crash or potentially escalate their privileges on the system. (CVE-2022-1882) - There exists a use-after-free in io_uring in the Linux kernel. Signalfd_poll() and binder_poll() use a waitqueue whose lifetime is the current task. It will send a POLLFREE notification to all waiters before the queue is freed. Unfortunately, the io_uring poll doesn't handle POLLFREE. This allows a use-after-free to occur if a signalfd or binder fd is polled with io_uring poll, and the waitqueue gets freed. We recommend upgrading past commit fc78b2fc21f10c4c9c4d5d659a685710ffa63659 (CVE-2022-3176) - Non-transparent sharing of return predictor targets between contexts in some Intel(R) Processors may allow an authorized user to potentially enable information disclosure via local access. (CVE-2022-26373) - An issue was discovered in the Linux kernel through 5.18.14. xfrm_expand_policies in net/xfrm/xfrm_policy.c can cause a refcount to be dropped twice. (CVE-2022-36879) - An issue was discovered the x86 KVM subsystem in the Linux kernel before 5.18.17. Unprivileged guest users can compromise the guest kernel because TLB flush operations are mishandled in certain KVM_VCPU_PREEMPTED situations. (CVE-2022-39189) Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.