{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "5035ebc644aec92d55d1bbfe042f35341e4bffb5"
            },
            {
              "fixed": "de5f69b8dae8698ac5e48dfcd30017887cdf4e5a"
            },
            {
              "fixed": "e441cbfbd0eaa6404278e985033c33caba4db767"
            },
            {
              "fixed": "2fed79f0fe8c8d28a972c290dbfd693c3546c8c4"
            },
            {
              "fixed": "560e21e8ccff813e84d05f6500907c549a3d6985"
            },
            {
              "fixed": "86237e56091e70f09c0fbf217f9d9c0e08f556c4"
            },
            {
              "fixed": "b902890c62d200b3509cb5e09cf1e0a66553c128"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.0.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.96"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.39"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64419.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show()\n\nReading the debugfs \"count\" file of a memcg-aware shrinker can sleep\ninside an RCU read-side critical section:\n\n  BUG: sleeping function called from invalid context at kernel/cgroup/rstat.c:421\n  RCU nest depth: 1, expected: 0\n   css_rstat_flush\n   mem_cgroup_flush_stats\n   zswap_shrinker_count\n   shrinker_debugfs_count_show\n\nshrinker_debugfs_count_show() invokes the -\u003ecount_objects() callback under\nrcu_read_lock().  The zswap callback flushes memcg stats via\ncss_rstat_flush(), which may sleep, so it must not run under RCU.\n\nThe RCU lock is not needed here.  mem_cgroup_iter() takes RCU internally\nand returns a memcg holding a css reference (dropped on the next iteration\nor by mem_cgroup_iter_break()), so the memcg stays alive without it.  The\nshrinker is kept alive by the open debugfs file: shrinker_free() removes\nthe debugfs entries via debugfs_remove_recursive(), which waits for\nin-flight readers to drain, before call_rcu(..., shrinker_free_rcu_cb). \nThe sibling \"scan\" handler already invokes the sleeping -\u003escan_objects()\ncallback with no RCU section.\n\nDrop the rcu_read_lock()/rcu_read_unlock().",
  "id": "CVE-2026-64419",
  "modified": "2026-07-27T03:56:29.419512470Z",
  "published": "2026-07-25T08:50:58.342Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2fed79f0fe8c8d28a972c290dbfd693c3546c8c4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/560e21e8ccff813e84d05f6500907c549a3d6985"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/86237e56091e70f09c0fbf217f9d9c0e08f556c4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b902890c62d200b3509cb5e09cf1e0a66553c128"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de5f69b8dae8698ac5e48dfcd30017887cdf4e5a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e441cbfbd0eaa6404278e985033c33caba4db767"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64419.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64419"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "mm/shrinker: do not hold RCU lock in shrinker_debugfs_count_show()"
}