Copyright © 2012 Red Hat, Inc. All rights reserved. Important 2026-07-25T00:00:00 kernel: HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CWE-787

In the Linux kernel, the following vulnerability has been resolved: HID: wacom: fix slab-out-of-bounds write in wacom_wac_queue_insert wacom_wac_queue_insert() calls kfifo_skip() in a loop when the kfifo doesn't have enough space for the incoming report. If the kfifo is empty, kfifo_skip() reads stale data left in the kmalloc'd buffer via __kfifo_peek_n() and interprets it as a record length, advancing fifo->out by that garbage value. This corrupts the internal kfifo state, causing kfifo_unused() to return a value much larger than the actual buffer size, which bypasses __kfifo_in_r()'s guard: if (len + recsize > kfifo_unused(fifo)) return 0; kfifo_copy_in() then performs an out-of-bounds memcpy, writing up to 3842 bytes past the 256-byte buffer. Add a !kfifo_is_empty() condition to the while loop so kfifo_skip() is never called on an empty fifo, and check the return value of kfifo_in() to reject reports that are too large for the fifo.

A flaw was found in the Linux kernel's Wacom Human Interface Device (HID) driver. This vulnerability occurs in the `wacom_wac_queue_insert` function when handling incoming reports. Improper management of the kernel's internal buffer (kfifo) can lead to a slab-out-of-bounds write, allowing an attacker to corrupt memory. This memory corruption could potentially result in a denial of service or, in some cases, arbitrary code execution.

Red Hat Enterprise Linux 10 Affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Not affected kernel Red Hat Enterprise Linux 8 Not affected kernel-rt Red Hat Enterprise Linux 9 Affected kernel Red Hat Enterprise Linux 9 Affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-64366 https://nvd.nist.gov/vuln/detail/CVE-2026-64366 https://lore.kernel.org/linux-cve-announce/2026072522-CVE-2026-64366-52d4@gregkh/T