net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete

Description

In the Linux kernel, the following vulnerability has been resolved: net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete When an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed the per-SC metadata_dst with metadata_dst_free(), which kfree()s the object unconditionally and ignores the dst reference count. The RX datapath in mlx5e_macsec_offload_handle_rx_skb() looks up the SC under rcu_read_lock() via xa_load(), takes a reference with dst_hold() and attaches the dst to the skb with skb_dst_set(). A reader that already obtained the rx_sc pointer can race with the delete path and operate on freed memory. Fix the owner side by dropping the reference with dst_release() instead of freeing unconditionally, and convert the RX datapath to dst_hold_safe() so a reader racing the SC delete cannot attach a dst whose last reference was just dropped; only attach it when a reference was actually taken. mlx5e_macsec_add_rxsc() also published sc_xarray_element via xa_alloc() before rx_sc->md_dst was allocated and initialised, so a datapath reader that looked the SC up by fs_id could observe rx_sc with md_dst still NULL or, on weakly-ordered architectures, a non-NULL md_dst pointer whose contents were not yet visible. NULL-check the xa_load() result and md_dst on the datapath, and reorder add_rxsc() so the xa_alloc() publish happens only after md_dst is fully initialised; the xarray RCU publish then pairs with the rcu_read_lock()/xa_load() in the datapath. Note: macsec_del_rxsc_ctx() also kfree()s rx_sc->sc_xarray_element without an RCU grace period while the same datapath reads it under rcu_read_lock(); that is a separate pre-existing issue left to a follow-up patch. Found by 0sec automated security-research tooling (https://0sec.ai).

Timeline

Scores

EPSS (exploitation in 30 days)

0.17% · top 93% of all CVEs (11 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Affected products

• Linux · Linux

  • affected b7c9400cbc48c3713190b3bce4e0c87e924e4104 – < b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb
  • affected b7c9400cbc48c3713190b3bce4e0c87e924e4104 – < 218cc15a4c907659ad4b0e68c535c61594311205
  • affected b7c9400cbc48c3713190b3bce4e0c87e924e4104 – < 4a5073b7b30243658f58b2d2d35a823da7fd34d9
  • affected b7c9400cbc48c3713190b3bce4e0c87e924e4104 – < ed3cc4218070d6b98bf5fb456dccae424fd38c4f
  • affected b7c9400cbc48c3713190b3bce4e0c87e924e4104 – < 088873af13590ebde10de2ade847f57a05ec61c6
  • affected b7c9400cbc48c3713190b3bce4e0c87e924e4104 – < de74d8fd10291763d97b218f09adcc7513c975e4

• Linux · Linux

  • affected 6.1
  • unaffected < 6.1
  • unaffected 6.1.178 – ≤ 6.1.*
  • unaffected 6.6.145 – ≤ 6.6.*
  • unaffected 6.12.97 – ≤ 6.12.*
  • unaffected 6.18.40 – ≤ 6.18.*
  • unaffected 7.1.5 – ≤ 7.1.*
  • unaffected 7.2 – ≤ *

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• EUVD EUVD-2026-59030 (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-72072](https://cveledger.app/badge/CVE-2026-72072.svg)](https://cveledger.app/cve/CVE-2026-72072)

Record last updated 19 Oct 2026, 21:19 UTC.