Red Hat Security Advisory: kernel security, bug fix, and enhancement update

Critical

A flaw was found in the Linux kernel's Remote Direct Memory Access (RDMA) `umad` (User Mode Access Device) component. A local user can exploit this vulnerability by manipulating input, causing an integer underflow that leads to an out-of-bounds memory write. This memory corruption can result in a denial of service (DoS) by crashing the system, and may also lead to limited information disclosure or data integrity issues.

CWE-131 - Incorrect Calculation of Buffer Size

A flaw was found in the Linux kernel's IPv6 tunnel implementation. A remote attacker could exploit this flaw by sending malicious ICMPv6 error messages to cause a stack-based buffer overflow in the kernel's IPv4-over-IPv6 tunnel error handling code. This could result in a kernel crash (denial of service) or potentially allow arbitrary code execution with kernel privileges.

CWE-843 - Access of Resource Using Incompatible Type ('Type Confusion')

A flaw was found in the Linux kernel's brcmfmac Wi-Fi driver. This vulnerability occurs because the driver fails to properly validate bsscfg indices in interface (IF) events. An attacker could exploit this by sending a specially crafted IF event with an invalid bsscfg index, which could lead to an out-of-bounds write or read, potentially causing a system crash and resulting in a denial of service (DoS).

CWE-1285 - Improper Validation of Specified Index, Position, or Offset in Input

A flaw was found in the Linux kernel's XFS filesystem. When adding extended attributes (xattrs), which are metadata associated with files, to leaf blocks, incorrect adjustments to the freemap can occur. This inconsistency allows the entries array and free space to overlap, leading to an assertion failure. A local user can exploit this to cause the filesystem to shut down, resulting in a Denial of Service (DoS).

CWE-617 - Reachable Assertion

A flaw was found in the Linux kernel, specifically within the netfilter: xt_tcpmss module. A remote attacker could exploit this vulnerability by sending a specially crafted TCP packet. The TCP option parser does not properly validate the remaining option length, which results in an out-of-bounds read. This allows an attacker to access memory beyond the intended buffer, potentially leading to information disclosure.

CWE-125 - Out-of-bounds Read