Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-07-25T00:00:00 kernel: ALSA: caiaq: fix out-of-bounds read in the Traktor Kontrol S4 input parser 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CWE-125

In the Linux kernel, the following vulnerability has been resolved: ALSA: caiaq: fix out-of-bounds read in the Traktor Kontrol S4 input parser snd_usb_caiaq_tks4_dispatch() decodes the Traktor Kontrol S4 input stream in fixed 16-byte (TKS4_MSGBLOCK_SIZE) message blocks. On every iteration it advances buf and subtracts the block size while looping on "while (len)". len is urb->actual_length. That value is supplied by the device and is not guaranteed to be a multiple of 16. When a final short block leaves len between 1 and 15, the loop runs once more, reads up to buf[15], and then does "len -= TKS4_MSGBLOCK_SIZE". As len is unsigned this underflows to a huge value. The loop then keeps iterating and walking buf far past the end of the 512-byte ep4_in_buf, reading out of bounds until a bogus block id happens to be hit. Iterate only while a full message block is available. This stops the unsigned underflow and silently drops any trailing partial block, which carries no complete control value anyway. The sibling endpoint-4 parsers are not affected. The Traktor Kontrol X1 and Maschine arms in snd_usb_caiaq_ep4_reply_dispatch() floor urb->actual_length before dispatching.

A flaw was found in the Linux kernel's sound subsystem, specifically within the ALSA caiaq driver responsible for handling Traktor Kontrol S4 devices. A local attacker, by providing specially crafted input from a connected device, could exploit an out-of-bounds read vulnerability. This issue arises from incorrect handling of input stream lengths, leading to the system reading beyond its allocated memory buffer. Successful exploitation could result in the disclosure of sensitive information from kernel memory or cause a system crash, leading to a denial of service.

Red Hat Enterprise Linux 10 Fix deferred kernel Red Hat Enterprise Linux 6 Out of support scope kernel Red Hat Enterprise Linux 7 Fix deferred kernel Red Hat Enterprise Linux 7 Fix deferred kernel-rt Red Hat Enterprise Linux 8 Fix deferred kernel Red Hat Enterprise Linux 8 Fix deferred kernel-rt Red Hat Enterprise Linux 9 Fix deferred kernel Red Hat Enterprise Linux 9 Fix deferred kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-64487 https://nvd.nist.gov/vuln/detail/CVE-2026-64487 https://lore.kernel.org/linux-cve-announce/2026072549-CVE-2026-64487-03f3@gregkh/T