CVE-2026-64366
⚠️ highSummary
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_unuse
Description
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.
📊 Relative Risk Intelligence
This CVE is High Risk - more severe than 81.0% of all 340,405 vulnerabilities in our database.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H