Vulnerability-Lookup

GHSA-C46H-F4QF-6CMR

Vulnerability from github – Published: 2026-08-05 09:31 – Updated: 2026-08-08 15:30

Details

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

wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure

ieee80211_set_unsol_bcast_probe_resp() calls kfree_rcu() on the old template before allocating the replacement. If the kzalloc() then fails, it returns -ENOMEM while link->u.ap.unsol_bcast_probe_resp still points at the object already queued for freeing. A later update or AP teardown re-queues that same rcu_head; the second free is caught by KASAN when the RCU sheaf is processed in softirq:

BUG: KASAN: double-free in rcu_free_sheaf (mm/slub.c:5850) Free of addr ffff88800d06f300 by task exploit/145 ... __rcu_free_sheaf_prepare (mm/slub.c:2634 mm/slub.c:2940) rcu_free_sheaf (mm/slub.c:5850) rcu_core (kernel/rcu/tree.c:2617 kernel/rcu/tree.c:2869) handle_softirqs (kernel/softirq.c:622) The buggy address belongs to the cache kmalloc-128 of size 128

Queue the old object for kfree_rcu() only after the new one is published, matching ieee80211_set_probe_resp() and ieee80211_set_s1g_short_beacon().

Severity

7.8 (High)


                  
                    CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64568"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-08-05T08:16:36Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure\n\nieee80211_set_unsol_bcast_probe_resp() calls kfree_rcu() on the old\ntemplate before allocating the replacement. If the kzalloc() then fails,\nit returns -ENOMEM while link-\u003eu.ap.unsol_bcast_probe_resp still points\nat the object already queued for freeing. A later update or AP teardown\nre-queues that same rcu_head; the second free is caught by KASAN when the\nRCU sheaf is processed in softirq:\n\n  BUG: KASAN: double-free in rcu_free_sheaf (mm/slub.c:5850)\n  Free of addr ffff88800d06f300 by task exploit/145\n   ...\n   __rcu_free_sheaf_prepare (mm/slub.c:2634 mm/slub.c:2940)\n   rcu_free_sheaf (mm/slub.c:5850)\n   rcu_core (kernel/rcu/tree.c:2617 kernel/rcu/tree.c:2869)\n   handle_softirqs (kernel/softirq.c:622)\n  The buggy address belongs to the cache kmalloc-128 of size 128\n\nQueue the old object for kfree_rcu() only after the new one is published,\nmatching ieee80211_set_probe_resp() and ieee80211_set_s1g_short_beacon().",
  "id": "GHSA-c46h-f4qf-6cmr",
  "modified": "2026-08-08T15:30:24Z",
  "published": "2026-08-05T09:31:17Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64568"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0ace76e410d7f7d813b605825a3e593a79c3958f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1d067abcd37062426c59ec73dbc4e87a63f33fea"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ca27a81cd77b698e5eb586a011bee6800c7ee4bd"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d62b55b7c7dc62887d7fd5648fb38f0bfaef53ae"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-64568 (GCVE-0-2026-64568)

Vulnerability from cvelistv5 – Published: 2026-08-05 08:08 – Updated: 2026-08-08 15:13

Title

wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure

Summary

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure ieee80211_set_unsol_bcast_probe_resp() calls kfree_rcu() on the old template before allocating the replacement. If the kzalloc() then fails, it returns -ENOMEM while link->u.ap.unsol_bcast_probe_resp still points at the object already queued for freeing. A later update or AP teardown re-queues that same rcu_head; the second free is caught by KASAN when the RCU sheaf is processed in softirq: BUG: KASAN: double-free in rcu_free_sheaf (mm/slub.c:5850) Free of addr ffff88800d06f300 by task exploit/145 ... __rcu_free_sheaf_prepare (mm/slub.c:2634 mm/slub.c:2940) rcu_free_sheaf (mm/slub.c:5850) rcu_core (kernel/rcu/tree.c:2617 kernel/rcu/tree.c:2869) handle_softirqs (kernel/softirq.c:622) The buggy address belongs to the cache kmalloc-128 of size 128 Queue the old object for kfree_rcu() only after the new one is published, matching ieee80211_set_probe_resp() and ieee80211_set_s1g_short_beacon().

Severity

7.8 (High)


                        
                          CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Assigner

Linux

References

4 references

URL	Tags
https://git.kernel.org/stable/c/ca27a81cd77b698e5…
https://git.kernel.org/stable/c/d62b55b7c7dc62887…
https://git.kernel.org/stable/c/0ace76e410d7f7d81…
https://git.kernel.org/stable/c/1d067abcd37062426…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 3b1c256eb4aedfc71dd97d5951ccff824b41d628 , < ca27a81cd77b698e5eb586a011bee6800c7ee4bd (git) Affected: 3b1c256eb4aedfc71dd97d5951ccff824b41d628 , < d62b55b7c7dc62887d7fd5648fb38f0bfaef53ae (git) Affected: 3b1c256eb4aedfc71dd97d5951ccff824b41d628 , < 0ace76e410d7f7d813b605825a3e593a79c3958f (git) Affected: 3b1c256eb4aedfc71dd97d5951ccff824b41d628 , < 1d067abcd37062426c59ec73dbc4e87a63f33fea (git)
Linux	Linux	Affected: 6.7 Unaffected: 0 , < 6.7 (semver) Unaffected: 6.12.101 , ≤ 6.12.* (semver) Unaffected: 6.18.42 , ≤ 6.18.* (semver) Unaffected: 7.1.6 , ≤ 7.1.* (semver) Unaffected: 7.2-rc4 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/mac80211/cfg.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ca27a81cd77b698e5eb586a011bee6800c7ee4bd",
              "status": "affected",
              "version": "3b1c256eb4aedfc71dd97d5951ccff824b41d628",
              "versionType": "git"
            },
            {
              "lessThan": "d62b55b7c7dc62887d7fd5648fb38f0bfaef53ae",
              "status": "affected",
              "version": "3b1c256eb4aedfc71dd97d5951ccff824b41d628",
              "versionType": "git"
            },
            {
              "lessThan": "0ace76e410d7f7d813b605825a3e593a79c3958f",
              "status": "affected",
              "version": "3b1c256eb4aedfc71dd97d5951ccff824b41d628",
              "versionType": "git"
            },
            {
              "lessThan": "1d067abcd37062426c59ec73dbc4e87a63f33fea",
              "status": "affected",
              "version": "3b1c256eb4aedfc71dd97d5951ccff824b41d628",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/mac80211/cfg.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.101",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.42",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.101",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.42",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc4",
                  "versionStartIncluding": "6.7",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure\n\nieee80211_set_unsol_bcast_probe_resp() calls kfree_rcu() on the old\ntemplate before allocating the replacement. If the kzalloc() then fails,\nit returns -ENOMEM while link-\u003eu.ap.unsol_bcast_probe_resp still points\nat the object already queued for freeing. A later update or AP teardown\nre-queues that same rcu_head; the second free is caught by KASAN when the\nRCU sheaf is processed in softirq:\n\n  BUG: KASAN: double-free in rcu_free_sheaf (mm/slub.c:5850)\n  Free of addr ffff88800d06f300 by task exploit/145\n   ...\n   __rcu_free_sheaf_prepare (mm/slub.c:2634 mm/slub.c:2940)\n   rcu_free_sheaf (mm/slub.c:5850)\n   rcu_core (kernel/rcu/tree.c:2617 kernel/rcu/tree.c:2869)\n   handle_softirqs (kernel/softirq.c:622)\n  The buggy address belongs to the cache kmalloc-128 of size 128\n\nQueue the old object for kfree_rcu() only after the new one is published,\nmatching ieee80211_set_probe_resp() and ieee80211_set_s1g_short_beacon()."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - Triggered only via local nl80211 SoftAP config (NL80211_CMD_START_AP/SET_BEACON/CHANNEL_SWITCH/COLOR_CHANGE \u2192 ieee80211_set_unsol_bcast_probe_resp), not by processing over-the-air WiFi frames or remote packets.\nAC:L - The attacker fully controls the SET_BEACON/STOP_AP sequence and can force the GFP_KERNEL kzalloc failure (e.g. memory pressure/memcg) with an attacker-chosen template size; no race or condition outside attacker influence is required.\nPR:L - START_AP and SET_BEACON use GENL_UNS_ADMIN_PERM (CAP_NET_ADMIN in the wiphy netns user_ns). Per CNA guidance that capability via user namespaces scores Low, not init-namespace root High.\nUI:N - The attacker issues the nl80211 commands to set the unsolicited broadcast probe response template and later tear down or update the AP; no separate victim action is required.\nS:U - Impact stays inside the host kernel mac80211 heap (local privilege-escalation class) and does not cross a VM, IOMMU, or other separate security authority.\nC:H - After the failed alloc the dangling unsol_bcast_probe_resp pointer can be read via ieee80211_get_unsol_bcast_probe_resp_tmpl and the object is double-freed; double-free/UAF enables heap reuse and arbitrary kernel memory disclosure.\nI:H - Double-free of the attacker-sized kmalloc unsol_bcast_probe_resp template (and subsequent stop_ap/update re-free) is classic heap corruption enabling spray/arbitrary-write and control-flow hijack primitives.\nA:H - The bug is a KASAN-confirmed double-free in rcu_free_sheaf softirq processing (task exploit/145) and can oops/panic the kernel, fully denying availability."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-08T15:13:09.507Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ca27a81cd77b698e5eb586a011bee6800c7ee4bd"
        },
        {
          "url": "https://git.kernel.org/stable/c/d62b55b7c7dc62887d7fd5648fb38f0bfaef53ae"
        },
        {
          "url": "https://git.kernel.org/stable/c/0ace76e410d7f7d813b605825a3e593a79c3958f"
        },
        {
          "url": "https://git.kernel.org/stable/c/1d067abcd37062426c59ec73dbc4e87a63f33fea"
        }
      ],
      "title": "wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64568",
    "datePublished": "2026-08-05T08:08:06.625Z",
    "dateReserved": "2026-07-19T15:36:31.797Z",
    "dateUpdated": "2026-08-08T15:13:09.507Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

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GHSA-C46H-F4QF-6CMR

CVE-2026-64568 (GCVE-0-2026-64568)

Tags

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Nomenclature