---
id: CVE-2026-64351
title: 'net: usb: kalmia: bound RX frame length in kalmia_rx_fixup()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net: usb: kalmia: bound RX frame length in kalmia_rx_fixup()

  kalmia_rx_fixup() computes usb_packet_length = skb->len - (2 *
  KALMIA_HEADER_LENGTH) as a u16, guarded onl…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    391706889a5112feafdc0c68db3ecc7ed325d09c
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    aa4eef2cbb66ea3dfcfc24bdce798dd78a81b54b
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    2d04c37ed4e1d0f733ad39ec35b5a5d8818b4f4a
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    46ab32870d010e9a057bc5659cea22b7e728ca88
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    c466097d85d52f3aa200736cb4759e66d4bbf6e3
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    e24eb271061db384a3c3ef6f107fe515e68ef222
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    51e65f1d78457ea4f9513d90ab22c9dccbb35110
  - >-
    Linux >= d40261236e8e278cb1936cb5e934262971692b10 <
    47b6bcef6e679593d2e86e04ee72c46a4e2f7139
  - Linux 3.0
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:36:37.686661Z'
published: '2026-07-25'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T16:44:48.462Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-64351'
references:
  - url: 'https://git.kernel.org/stable/c/391706889a5112feafdc0c68db3ecc7ed325d09c'
  - url: 'https://git.kernel.org/stable/c/aa4eef2cbb66ea3dfcfc24bdce798dd78a81b54b'
  - url: 'https://git.kernel.org/stable/c/2d04c37ed4e1d0f733ad39ec35b5a5d8818b4f4a'
  - url: 'https://git.kernel.org/stable/c/46ab32870d010e9a057bc5659cea22b7e728ca88'
  - url: 'https://git.kernel.org/stable/c/c466097d85d52f3aa200736cb4759e66d4bbf6e3'
  - url: 'https://git.kernel.org/stable/c/e24eb271061db384a3c3ef6f107fe515e68ef222'
  - url: 'https://git.kernel.org/stable/c/51e65f1d78457ea4f9513d90ab22c9dccbb35110'
  - url: 'https://git.kernel.org/stable/c/47b6bcef6e679593d2e86e04ee72c46a4e2f7139'
tags:
  - cve.org
epss: 0.0013
epssPercentile: 0.02674
ingestedAt: '2026-11-06T16:57:43.190Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

net: usb: kalmia: bound RX frame length in kalmia_rx_fixup()

kalmia_rx_fixup() computes usb_packet_length = skb->len - (2 *
KALMIA_HEADER_LENGTH) as a u16, guarded only by a pre-loop check that
skb->len is at least KALMIA_HEADER_LENGTH, which is 6. A device can
deliver a short bulk-IN frame with skb->len in the 6 to 11 range, or
leave a short trailing remainder on a later loop iteration. Either case
underflows usb_packet_length to about 65530.

That bypasses the usb_packet_length < ether_packet_length truncation path.
The device-supplied ether_packet_length, a le16 up to 65535 read from
header_start[2], then drives a memcmp() and the following skb_trim() and
skb_pull() past the end of the rx buffer. The rx buffer is hard_mtu * 10,
which is 14000 bytes. That is an out of bounds read.

Require both the start and end framing headers to be present before
subtracting them, on every loop iteration.

## Affected

- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < 391706889a5112feafdc0c68db3ecc7ed325d09c`
- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < aa4eef2cbb66ea3dfcfc24bdce798dd78a81b54b`
- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < 2d04c37ed4e1d0f733ad39ec35b5a5d8818b4f4a`
- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < 46ab32870d010e9a057bc5659cea22b7e728ca88`
- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < c466097d85d52f3aa200736cb4759e66d4bbf6e3`
- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < e24eb271061db384a3c3ef6f107fe515e68ef222`
- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < 51e65f1d78457ea4f9513d90ab22c9dccbb35110`
- `Linux >= d40261236e8e278cb1936cb5e934262971692b10 < 47b6bcef6e679593d2e86e04ee72c46a4e2f7139`
- `Linux 3.0`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.