---
id: CVE-2022-49973
title: 'skmsg: Fix wrong last sg check in sk_msg_recvmsg()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  skmsg: Fix wrong last sg check in sk_msg_recvmsg()

  Fix one kernel NULL pointer dereference as below:

  [  224.462334] Call Trace:
  [  224.462394]  __tcp_bpf_recvmsg+0xd3…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 293c53b7dbf9073cbcc488f938bc053ff4caeec0 <
    de22cba333d8699ad77e79f862fe1320cb1284de
  - >-
    Linux >= 1295dae30f30c3daa03005ed8958d44b17f037fd <
    10ee118a1756141f8e9c87aa7344ed12b41630a8
  - >-
    Linux >= 9974d37ea75f01b47d16072b5dad305bd8d23fcc <
    583585e48d965338e73e1eb383768d16e0922d73
  - Linux 4674c0da448b546e390a981b819cd4af5cb16cf9
  - Linux >= 5.18.18 < 5.19
  - Linux >= 5.15.61 < 5.15.66
  - Linux >= 5.19.2 < 5.19.8
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:52:17.325840Z'
published: '2025-06-18'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:00:12.759Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-49973'
references:
  - url: 'https://git.kernel.org/stable/c/de22cba333d8699ad77e79f862fe1320cb1284de'
  - url: 'https://git.kernel.org/stable/c/10ee118a1756141f8e9c87aa7344ed12b41630a8'
  - url: 'https://git.kernel.org/stable/c/583585e48d965338e73e1eb383768d16e0922d73'
tags:
  - cve.org
epss: 0.00243
epssPercentile: 0.15512
ingestedAt: '2026-11-05T22:38:31.630Z'
---

## Overview

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

skmsg: Fix wrong last sg check in sk_msg_recvmsg()

Fix one kernel NULL pointer dereference as below:

[  224.462334] Call Trace:
[  224.462394]  __tcp_bpf_recvmsg+0xd3/0x380
[  224.462441]  ? sock_has_perm+0x78/0xa0
[  224.462463]  tcp_bpf_recvmsg+0x12e/0x220
[  224.462494]  inet_recvmsg+0x5b/0xd0
[  224.462534]  __sys_recvfrom+0xc8/0x130
[  224.462574]  ? syscall_trace_enter+0x1df/0x2e0
[  224.462606]  ? __do_page_fault+0x2de/0x500
[  224.462635]  __x64_sys_recvfrom+0x24/0x30
[  224.462660]  do_syscall_64+0x5d/0x1d0
[  224.462709]  entry_SYSCALL_64_after_hwframe+0x65/0xca

In commit 9974d37ea75f ("skmsg: Fix invalid last sg check in
sk_msg_recvmsg()"), we change last sg check to sg_is_last(),
but in sockmap redirection case (without stream_parser/stream_verdict/
skb_verdict), we did not mark the end of the scatterlist. Check the
sk_msg_alloc, sk_msg_page_add, and bpf_msg_push_data functions, they all
do not mark the end of sg. They are expected to use sg.end for end
judgment. So the judgment of '(i != msg_rx->sg.end)' is added back here.

## Affected

- `Linux >= 293c53b7dbf9073cbcc488f938bc053ff4caeec0 < de22cba333d8699ad77e79f862fe1320cb1284de`
- `Linux >= 1295dae30f30c3daa03005ed8958d44b17f037fd < 10ee118a1756141f8e9c87aa7344ed12b41630a8`
- `Linux >= 9974d37ea75f01b47d16072b5dad305bd8d23fcc < 583585e48d965338e73e1eb383768d16e0922d73`
- `Linux 4674c0da448b546e390a981b819cd4af5cb16cf9`
- `Linux >= 5.18.18 < 5.19`
- `Linux >= 5.15.61 < 5.15.66`
- `Linux >= 5.19.2 < 5.19.8`

## Remediation

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