---
id: CVE-2026-98600
title: 'Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()

  While rfcomm_recv_frame() verifies that skb->len is at least
  sizeof(*hdr) + 1 (4 bytes: 3-byte heade…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= fb40eda15122f6b780228639c1ead6820340ff54 <
    76876fd26569302d26d91cbe8b75fa8e66cf8969
  - >-
    Linux >= 3829af5fab5a22405bf1e7d69068c2ec0fce46ca <
    97711b964877242933484989224a3c4c5d88a5ee
  - >-
    Linux >= b161eacd7fa4a2d765724b5504ac6cc388e48f80 <
    7a1781a2f3a9667b3065d402d1f11986a2363e08
  - >-
    Linux >= 30d1d9f3495463f7c026e4c553127f79b486fcd6 <
    c25587fa26761e623198b4f47151fe79d09ccde6
  - >-
    Linux >= 67dc3b40fae71b6b11c71e7ff69bac0758818c05 <
    71ccacde407b7d8f0ef48974a0d2524602fd5c44
  - >-
    Linux >= bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51 <
    be00deee60044ffa820f9436415caeb665b2cda0
  - >-
    Linux >= b230e5bf501c5edaf2eb0991cb862ac142031d4b <
    9240fc1f2cde5331c61608da21b00394602ca762
  - >-
    Linux >= b230e5bf501c5edaf2eb0991cb862ac142031d4b <
    6d91041bb38b97e2feb625123cc0529d7b83a0e1
  - Linux >= 6.12.111 < 6.12.112
  - Linux >= 6.18.53 < 6.18.55
  - Linux 7.2
published: '2026-10-18'
updated: '2026-10-18'
sourceUpdated: '2026-10-18T15:19:12.864Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-98600'
references:
  - url: 'https://git.kernel.org/stable/c/76876fd26569302d26d91cbe8b75fa8e66cf8969'
  - url: 'https://git.kernel.org/stable/c/97711b964877242933484989224a3c4c5d88a5ee'
  - url: 'https://git.kernel.org/stable/c/7a1781a2f3a9667b3065d402d1f11986a2363e08'
  - url: 'https://git.kernel.org/stable/c/c25587fa26761e623198b4f47151fe79d09ccde6'
  - url: 'https://git.kernel.org/stable/c/71ccacde407b7d8f0ef48974a0d2524602fd5c44'
  - url: 'https://git.kernel.org/stable/c/be00deee60044ffa820f9436415caeb665b2cda0'
  - url: 'https://git.kernel.org/stable/c/9240fc1f2cde5331c61608da21b00394602ca762'
  - url: 'https://git.kernel.org/stable/c/6d91041bb38b97e2feb625123cc0529d7b83a0e1'
tags:
  - cve.org
ingestedAt: '2026-10-18T15:45:12.248Z'
---

## Overview

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

Bluetooth: RFCOMM: Reject short EA=0 frames in rfcomm_recv_frame()

While rfcomm_recv_frame() verifies that skb->len is at least
sizeof(*hdr) + 1 (4 bytes: 3-byte header + 1-byte FCS), an RFCOMM frame
with an extended 2-byte length field (!__test_ea(hdr->len)) has a 4-byte
header plus a 1-byte FCS (5 bytes minimum, sizeof(*hdr) + 2).

When a 4-byte RFCOMM frame with EA == 0 arrives:
1. The initial skb->len < sizeof(*hdr) + 1 check passes (4 < 4 is false).
2. Trimming the FCS byte decrements skb->len to 3.
3. If __check_fcs() succeeds, skb_pull(skb, 4) fails (4 > 3) and returns
   NULL without advancing skb->data.
4. Because the return value of skb_pull() is ignored, the un-pulled
   3-byte struct rfcomm_hdr remains at skb->data and is either queued as
   application payload via rfcomm_recv_data() or parsed as a multiplexer
   control command via rfcomm_recv_mcc() on DLCI 0.

Fix this by extending the length check in rfcomm_recv_frame() to also
require skb->len >= sizeof(*hdr) + 2 when !__test_ea(hdr->len).

## Affected

- `Linux >= fb40eda15122f6b780228639c1ead6820340ff54 < 76876fd26569302d26d91cbe8b75fa8e66cf8969`
- `Linux >= 3829af5fab5a22405bf1e7d69068c2ec0fce46ca < 97711b964877242933484989224a3c4c5d88a5ee`
- `Linux >= b161eacd7fa4a2d765724b5504ac6cc388e48f80 < 7a1781a2f3a9667b3065d402d1f11986a2363e08`
- `Linux >= 30d1d9f3495463f7c026e4c553127f79b486fcd6 < c25587fa26761e623198b4f47151fe79d09ccde6`
- `Linux >= 67dc3b40fae71b6b11c71e7ff69bac0758818c05 < 71ccacde407b7d8f0ef48974a0d2524602fd5c44`
- `Linux >= bbc310caa2b6bf5fe42896ba27da0fbc12e4ac51 < be00deee60044ffa820f9436415caeb665b2cda0`
- `Linux >= b230e5bf501c5edaf2eb0991cb862ac142031d4b < 9240fc1f2cde5331c61608da21b00394602ca762`
- `Linux >= b230e5bf501c5edaf2eb0991cb862ac142031d4b < 6d91041bb38b97e2feb625123cc0529d7b83a0e1`
- `Linux >= 6.12.111 < 6.12.112`
- `Linux >= 6.18.53 < 6.18.55`
- `Linux 7.2`

## Remediation

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