Red Hat Security Advisory: kernel security update

Important

A flaw was found in the Linux kernel. A race condition exists in the TCP (Transmission Control Protocol) IPv6 (Internet Protocol version 6) socket handling, specifically within the tcp_v6_syn_recv_sock() function. This occurs because a child socket becomes visible in the TCP hash table before its IPv6-specific information is fully initialized. A remote attacker could potentially exploit this timing window, leading to an unstable system state or unexpected behavior, which may result in a denial of service (DoS).

CWE-821 - Incorrect Synchronization

A flaw was found in the Linux kernel's ALSA (Advanced Linux Sound Architecture) aloop driver. This Use-After-Free (UAF) vulnerability occurs when loopback_check_format() stops the capture side during a format change, while a concurrent close operation detaches or frees the runtime. An attacker could potentially exploit this to cause a system crash or achieve arbitrary code execution.

CWE-364 - Signal Handler Race Condition

A flaw was found in the Linux kernel's RDMA/mlx4 component. This vulnerability arises from the incorrect use of Read-Copy Update (RCU) in the `mlx4_srq_event()` function. An attacker could potentially trigger an event before the `srq` object is fully initialized, leading to a system crash. This could result in a Denial of Service (DoS) for the affected system.

CWE-366 - Race Condition within a Thread

A flaw was found in the Linux kernel's netfilter subsystem, specifically within the nft_inner module. This vulnerability arises from an incorrect handling of IPv6 inner packet processing, where the transport header offset (inner_thoff) becomes desynchronized from the Layer 4 protocol (l4proto). A remote attacker could exploit this desynchronization to perform transport header forgery, potentially leading to a firewall bypass and allowing unauthorized network access.

CWE-823 - Use of Out-of-range Pointer Offset