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CVE-2026-74338

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Reject sleepable BPF_LSM_CGROUP programs at load time The cgroup shim runs under rcu_read_lock_dont_migrate(), so we should not attach any sleepable BPF programs there. Add support to the verifier to explicitly reject attempts to load sleepable BPF programs destined for LSM cgroup attachment. Without this, we get the following splat from a BPF_LSM_CGROUP program marked BPF_F_SLEEPABLE attached to file_open when it calls bpf_get_dentry_xattr(): BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1567 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 34317, name: load preempt_count: 0, expected: 0 RCU nest depth: 2, expected: 0 Call Trace: down_read+0x76/0x480 ext4_xattr_get+0x11f/0x700 __vfs_getxattr+0xf0/0x150 bpf_get_dentry_xattr+0xbb/0xf0 bpf_prog_e76a298dac9218c6_test_open+0x6a/0x85 __cgroup_bpf_run_lsm_current+0x326/0x840 bpf_trampoline_6442534646+0x62/0x14d security_file_open+0x34/0x60 do_dentry_open+0x340/0x1260 vfs_open+0x7a/0x440 path_openat+0x1bac/0x30a0 libbpf provides a .s named section variant for every sleepable program type except lsm_cgroup, reflecting that per-cgroup LSM programs are intended to only run in a non-sleepable context. The above splat was obtained by bypassing libbpf by using bpf(2) directly.

Severity
HIGH
CVSS score
7.8 (v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-15 06:22:34.740000
Last modified
2026-10-30 13:19:55.210000
View original CVE JSON
{
  "id": "CVE-2026-74338",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-15T06:22:34.740",
  "lastModified": "2026-10-30T13:19:55.210",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject sleepable BPF_LSM_CGROUP programs at load time\n\nThe cgroup shim runs under rcu_read_lock_dont_migrate(), so we should\nnot attach any sleepable BPF programs there. Add support to the verifier\nto explicitly reject attempts to load sleepable BPF programs destined\nfor LSM cgroup attachment.\n\nWithout this, we get the following splat from a BPF_LSM_CGROUP\nprogram marked BPF_F_SLEEPABLE attached to file_open when it calls\nbpf_get_dentry_xattr():\n\n  BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1567\n  in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 34317, name: load\n  preempt_count: 0, expected: 0\n  RCU nest depth: 2, expected: 0\n  Call Trace:\n   down_read+0x76/0x480\n   ext4_xattr_get+0x11f/0x700\n   __vfs_getxattr+0xf0/0x150\n   bpf_get_dentry_xattr+0xbb/0xf0\n   bpf_prog_e76a298dac9218c6_test_open+0x6a/0x85\n   __cgroup_bpf_run_lsm_current+0x326/0x840\n   bpf_trampoline_6442534646+0x62/0x14d\n   security_file_open+0x34/0x60\n   do_dentry_open+0x340/0x1260\n   vfs_open+0x7a/0x440\n   path_openat+0x1bac/0x30a0\n\nlibbpf provides a .s named section variant for every sleepable\nprogram type except lsm_cgroup, reflecting that per-cgroup LSM programs\nare intended to only run in a non-sleepable context.\n\nThe above splat was obtained by bypassing libbpf by using bpf(2)\ndirectly."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e",
              "lessThan": "b0c76212af693734e5a2c9e9a48568f99f5bc46c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e",
              "lessThan": "f0a49d16804d319774388a32d8cdcef319a9e481",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e",
              "lessThan": "4b9d8bdeb19e709f9bc3c317d48b0c0add3b2b1d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e",
              "lessThan": "b4059a1f57eff3e206d44697f64ad81076512760",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e",
              "lessThan": "be9eaf2bb5db4ad3de61ef739fd268fd7f135737",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "69fd337a975c7e690dfe49d9cb4fe5ba1e6db44e",
              "lessThan": "5b038319be442c620f774e6fc9e9283deeca1c75",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "kernel/bpf/verifier.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.0",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.0",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.57",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.5",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T18:53:52.626746Z",
          "id": "CVE-2026-74338",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/4b9d8bdeb19e709f9bc3c317d48b0c0add3b2b1d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5b038319be442c620f774e6fc9e9283deeca1c75",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b0c76212af693734e5a2c9e9a48568f99f5bc46c",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/b4059a1f57eff3e206d44697f64ad81076512760",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/be9eaf2bb5db4ad3de61ef739fd268fd7f135737",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f0a49d16804d319774388a32d8cdcef319a9e481",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}