---
id: CVE-2026-80983
title: 'net/smc: fix socket refcount leak in smc_switch_conns()'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  net/smc: fix socket refcount leak in smc_switch_conns()

  smc_switch_conns() takes a reference on the SMC socket before dropping
  lgr->conns_lock, so the connection stays…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
cwe:
  - CWE-911
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a <
    a3378466704e0bbe93aef9769552dca7673a7eb6
  - >-
    Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a <
    e20227019d9da73f8fdf16f0951c2e188c84933f
  - >-
    Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a <
    09d7a9e162ee1a269878c126aee3d7eff43e4130
  - >-
    Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a <
    84dea0585f6b538ae895a8b1d025f4897737f3b1
  - >-
    Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a <
    d89dc1bd8845c669a700eee58c64ebd3cc1b6d2d
  - >-
    Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a <
    d9a879ac25958bdaecb669ce70e58f8e2ff170de
  - >-
    Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a <
    719296c4aa8213d4ac8002e77d5956d436bc98d0
  - Linux 99f19566b1c4d3dc4d934ee2ef43faadebb56d70
  - Linux 0d9ddf515cde793841f738490037560fd6559c63
  - Linux >= 5.10.90 < 5.11
  - Linux >= 5.14.14 < 5.15
  - Linux 5.15
published: '2026-09-11'
updated: '2026-10-19'
sourceUpdated: '2026-10-19T08:46:07.693Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-80983'
references:
  - url: 'https://git.kernel.org/stable/c/a3378466704e0bbe93aef9769552dca7673a7eb6'
  - url: 'https://git.kernel.org/stable/c/e20227019d9da73f8fdf16f0951c2e188c84933f'
  - url: 'https://git.kernel.org/stable/c/09d7a9e162ee1a269878c126aee3d7eff43e4130'
  - url: 'https://git.kernel.org/stable/c/84dea0585f6b538ae895a8b1d025f4897737f3b1'
  - url: 'https://git.kernel.org/stable/c/d89dc1bd8845c669a700eee58c64ebd3cc1b6d2d'
  - url: 'https://git.kernel.org/stable/c/d9a879ac25958bdaecb669ce70e58f8e2ff170de'
  - url: 'https://git.kernel.org/stable/c/719296c4aa8213d4ac8002e77d5956d436bc98d0'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80983.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-80983'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532201'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-80983'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-80983'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-80983.mbox
tags:
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00173
epssPercentile: 0.06615
ingestedAt: '2026-09-14T15:23:07.454Z'
---

## Overview

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

net/smc: fix socket refcount leak in smc_switch_conns()

smc_switch_conns() takes a reference on the SMC socket before dropping
lgr->conns_lock, so the connection stays alive while the CDC slot is
fetched:

        sock_hold(&smc->sk);
        read_unlock_bh(&lgr->conns_lock);
        /* pre-fetch buffer outside of send_lock, might sleep */
        rc = smc_cdc_get_free_slot(conn, to_lnk, &wr_buf, NULL, &pend);
        if (rc)
                goto err_out;

The err_out label only drops the wr_tx link reference, so this early exit
returns without the matching sock_put(). The second error exit is not
affected, because sock_put() has already run by then.

A leaked sk_refcnt means the smc_sock is never destroyed. Its send and
receive buffers stay allocated, and for a user socket the reference held
on the network namespace is never released, so the netns can no longer be
torn down.

smc_cdc_get_free_slot() fails when the target link goes down or when the
connection has been killed while the switch is in progress. Both are
reachable during the link failover this function implements, so the leak
is triggered by the same hardware events that make smc_switch_conns() run
in the first place.

Restructure so there is a single sock_put() covering both outcomes,
instead of adding a second one to the error path.

## Affected

- `Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a < a3378466704e0bbe93aef9769552dca7673a7eb6`
- `Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a < e20227019d9da73f8fdf16f0951c2e188c84933f`
- `Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a < 09d7a9e162ee1a269878c126aee3d7eff43e4130`
- `Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a < 84dea0585f6b538ae895a8b1d025f4897737f3b1`
- `Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a < d89dc1bd8845c669a700eee58c64ebd3cc1b6d2d`
- `Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a < d9a879ac25958bdaecb669ce70e58f8e2ff170de`
- `Linux >= 95f7f3e7dc6bd2e735cb5de11734ea2222b1e05a < 719296c4aa8213d4ac8002e77d5956d436bc98d0`
- `Linux 99f19566b1c4d3dc4d934ee2ef43faadebb56d70`
- `Linux 0d9ddf515cde793841f738490037560fd6559c63`
- `Linux >= 5.10.90 < 5.11`
- `Linux >= 5.14.14 < 5.15`
- `Linux 5.15`

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · updated 2026-10-17 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-80983.json)