{"id":"CVE-2026-72072","title":"net/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete\n\nWhen an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed\nthe per-SC metadata_dst wi…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb","Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < 218cc15a4c907659ad4b0e68c535c61594311205","Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < 4a5073b7b30243658f58b2d2d35a823da7fd34d9","Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < ed3cc4218070d6b98bf5fb456dccae424fd38c4f","Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < 088873af13590ebde10de2ade847f57a05ec61c6","Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < de74d8fd10291763d97b218f09adcc7513c975e4","Linux 6.1"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:51:23.230539Z"},"published":"2026-08-15","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:53:19.757Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-72072","references":[{"url":"https://git.kernel.org/stable/c/b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb"},{"url":"https://git.kernel.org/stable/c/218cc15a4c907659ad4b0e68c535c61594311205"},{"url":"https://git.kernel.org/stable/c/4a5073b7b30243658f58b2d2d35a823da7fd34d9"},{"url":"https://git.kernel.org/stable/c/ed3cc4218070d6b98bf5fb456dccae424fd38c4f"},{"url":"https://git.kernel.org/stable/c/088873af13590ebde10de2ade847f57a05ec61c6"},{"url":"https://git.kernel.org/stable/c/de74d8fd10291763d97b218f09adcc7513c975e4"}],"tags":["cve.org"],"epss":0.00171,"epssPercentile":0.06061,"ingestedAt":"2026-10-16T17:24:46.876Z","slug":"CVE-2026-72072","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: macsec: fix use-after-free of metadata_dst on RX SC delete\n\nWhen an offloaded MACsec RX SC is deleted, macsec_del_rxsc_ctx() freed\nthe per-SC metadata_dst with metadata_dst_free(), which kfree()s the\nobject unconditionally and ignores the dst reference count. The RX\ndatapath in mlx5e_macsec_offload_handle_rx_skb() looks up the SC under\nrcu_read_lock() via xa_load(), takes a reference with dst_hold() and\nattaches the dst to the skb with skb_dst_set(). A reader that already\nobtained the rx_sc pointer can race with the delete path and operate on\nfreed memory.\n\nFix the owner side by dropping the reference with dst_release() instead\nof freeing unconditionally, and convert the RX datapath to\ndst_hold_safe() so a reader racing the SC delete cannot attach a dst\nwhose last reference was just dropped; only attach it when a reference\nwas actually taken.\n\nmlx5e_macsec_add_rxsc() also published sc_xarray_element via xa_alloc()\nbefore rx_sc->md_dst was allocated and initialised, so a datapath reader\nthat looked the SC up by fs_id could observe rx_sc with md_dst still\nNULL or, on weakly-ordered architectures, a non-NULL md_dst pointer\nwhose contents were not yet visible. NULL-check the xa_load() result and\nmd_dst on the datapath, and reorder add_rxsc() so the xa_alloc() publish\nhappens only after md_dst is fully initialised; the xarray RCU publish\nthen pairs with the rcu_read_lock()/xa_load() in the datapath.\n\nNote: macsec_del_rxsc_ctx() also kfree()s rx_sc->sc_xarray_element\nwithout an RCU grace period while the same datapath reads it under\nrcu_read_lock(); that is a separate pre-existing issue left to a\nfollow-up patch.\n\nFound by 0sec automated security-research tooling (https://0sec.ai).\n\n## Affected\n\n- `Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < b1a4d0c568bbb52c7c04f4fce3c097dae89ed6cb`\n- `Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < 218cc15a4c907659ad4b0e68c535c61594311205`\n- `Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < 4a5073b7b30243658f58b2d2d35a823da7fd34d9`\n- `Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < ed3cc4218070d6b98bf5fb456dccae424fd38c4f`\n- `Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < 088873af13590ebde10de2ade847f57a05ec61c6`\n- `Linux >= b7c9400cbc48c3713190b3bce4e0c87e924e4104 < de74d8fd10291763d97b218f09adcc7513c975e4`\n- `Linux 6.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}