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Improper Update of Reference Count The advisory has been revoked - it doesn't affect any version of package perf  (opens in a new tab)

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0.17% (7th percentile)

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  • Snyk IDSNYK-CENTOS6-PERF-14705825
  • published26 Dec 2025
  • disclosed24 Dec 2025
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Introduced: 24 Dec 2025

CVE-2025-68366  (opens in a new tab)
CWE-911  (opens in a new tab)

Amendment

The Centos security team deemed this advisory irrelevant for Centos:6.

NVD Description

Note: Versions mentioned in the description apply only to the upstream perf package and not the perf package as distributed by Centos.

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

nbd: defer config unlock in nbd_genl_connect

There is one use-after-free warning when running NBD_CMD_CONNECT and NBD_CLEAR_SOCK:

nbd_genl_connect nbd_alloc_and_init_config // config_refs=1 nbd_start_device // config_refs=2 set NBD_RT_HAS_CONFIG_REF open nbd // config_refs=3 recv_work done // config_refs=2 NBD_CLEAR_SOCK // config_refs=1 close nbd // config_refs=0 refcount_inc -> uaf

------------[ cut here ]------------ refcount_t: addition on 0; use-after-free. WARNING: CPU: 24 PID: 1014 at lib/refcount.c:25 refcount_warn_saturate+0x12e/0x290 nbd_genl_connect+0x16d0/0x1ab0 genl_family_rcv_msg_doit+0x1f3/0x310 genl_rcv_msg+0x44a/0x790

The issue can be easily reproduced by adding a small delay before refcount_inc(&nbd->config_refs) in nbd_genl_connect():

    mutex_unlock(&nbd->config_lock);
    if (!ret) {
            set_bit(NBD_RT_HAS_CONFIG_REF, &config->runtime_flags);

  •           printk("before sleep\n");

  •           mdelay(5 * 1000);

  •           printk("after sleep\n");
          refcount_inc(&nbd->config_refs);
          nbd_connect_reply(info, nbd->index);
  }