---
id: CVE-2022-49838
title: 'sctp: clear out_curr if all frag chunks of current msg are pruned'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  sctp: clear out_curr if all frag chunks of current msg are pruned

  A crash was reported by Zhen Chen:

    list_del corruption, ffffa035ddf01c18->next is NULL
    WARNING: …
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <
    e27458b18b35caee4b27b37a4a9c503b93cae5cc
  - >-
    Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <
    2ea600b598dd3e061854dd4dd5b4c815397dfcea
  - >-
    Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <
    3eff34e01062ec08fbb45ce2baaaa644550be821
  - >-
    Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 <
    2f201ae14ae0f91dbf1cffea7bb1e29e81d4d108
  - Linux 4.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-05T19:50:40.509260Z'
published: '2025-05-01'
updated: '2026-11-05'
sourceUpdated: '2026-11-05T20:00:09.460Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2022-49838'
references:
  - url: 'https://git.kernel.org/stable/c/e27458b18b35caee4b27b37a4a9c503b93cae5cc'
  - url: 'https://git.kernel.org/stable/c/2ea600b598dd3e061854dd4dd5b4c815397dfcea'
  - url: 'https://git.kernel.org/stable/c/3eff34e01062ec08fbb45ce2baaaa644550be821'
  - url: 'https://git.kernel.org/stable/c/2f201ae14ae0f91dbf1cffea7bb1e29e81d4d108'
tags:
  - cve.org
epss: 0.00215
epssPercentile: 0.11977
ingestedAt: '2026-11-05T22:38:31.617Z'
---

## Overview

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

sctp: clear out_curr if all frag chunks of current msg are pruned

A crash was reported by Zhen Chen:

  list_del corruption, ffffa035ddf01c18->next is NULL
  WARNING: CPU: 1 PID: 250682 at lib/list_debug.c:49 __list_del_entry_valid+0x59/0xe0
  RIP: 0010:__list_del_entry_valid+0x59/0xe0
  Call Trace:
   sctp_sched_dequeue_common+0x17/0x70 [sctp]
   sctp_sched_fcfs_dequeue+0x37/0x50 [sctp]
   sctp_outq_flush_data+0x85/0x360 [sctp]
   sctp_outq_uncork+0x77/0xa0 [sctp]
   sctp_cmd_interpreter.constprop.0+0x164/0x1450 [sctp]
   sctp_side_effects+0x37/0xe0 [sctp]
   sctp_do_sm+0xd0/0x230 [sctp]
   sctp_primitive_SEND+0x2f/0x40 [sctp]
   sctp_sendmsg_to_asoc+0x3fa/0x5c0 [sctp]
   sctp_sendmsg+0x3d5/0x440 [sctp]
   sock_sendmsg+0x5b/0x70

and in sctp_sched_fcfs_dequeue() it dequeued a chunk from stream
out_curr outq while this outq was empty.

Normally stream->out_curr must be set to NULL once all frag chunks of
current msg are dequeued, as we can see in sctp_sched_dequeue_done().
However, in sctp_prsctp_prune_unsent() as it is not a proper dequeue,
sctp_sched_dequeue_done() is not called to do this.

This patch is to fix it by simply setting out_curr to NULL when the
last frag chunk of current msg is dequeued from out_curr stream in
sctp_prsctp_prune_unsent().

## Affected

- `Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 < e27458b18b35caee4b27b37a4a9c503b93cae5cc`
- `Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 < 2ea600b598dd3e061854dd4dd5b4c815397dfcea`
- `Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 < 3eff34e01062ec08fbb45ce2baaaa644550be821`
- `Linux >= 5bbbbe32a43199c2b9ea5ea66fab6241c64beb51 < 2f201ae14ae0f91dbf1cffea7bb1e29e81d4d108`
- `Linux 4.15`

## Remediation

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