bpf: Fix crash due to incorrect copy_map_value

{
  "id": "4f412a7d7bbe5eb3fe2291b730407a7b4d5dac999a99fc0610a14ef9e868f11d",
  "url": "https://osv.dev/vulnerability/CVE-2022-48940",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bpf: Fix crash due to incorrect copy_map_value",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf: Fix crash due to incorrect copy_map_value When both bpf_spin_lock and bpf_timer are present in a BPF map value, copy_map_value needs to skirt both objects when copying a value into and out of the map. However, the current code does not set both s_off and t_off in copy_map_value, which leads to a crash when e.g. bpf_spin_lock is placed in map value with bpf_timer, as bpf_map_update_elem call will be able to overwrite the other timer object. When the issue is not fixed, an overwriting can produce the following splat: [root@(none) bpf]# ./test_progs -t timer_crash [ 15.930339] bpf_testmod: loading out-of-tree module taints kernel. [ 16.037849] ================================================================== [ 16.038458] BUG: KASAN: user-memory-access in __pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.038944] Write of size 8 at addr 0000000000043ec0 by task test_progs/325 [ 16.039399] [ 16.039514] CPU: 0 PID: 325 Comm: test_progs Tainted: G OE 5.16.0+ #278 [ 16.039983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.15.0-1 04/01/2014 [ 16.040485] Call Trace: [ 16.040645] [ 16.040805] dump_stack_lvl+0x59/0x73 [ 16.041069] ? __pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.041427] kasan_report.cold+0x116/0x11b [ 16.041673] ? __pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.042040] __pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.042328] ? memcpy+0x39/0x60 [ 16.042552] ? pv_hash+0xd0/0xd0",
    "evidence": "osv:CVE-2022-48940",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.15.26",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "5.16.12",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2022-48940",
      "aliases": [
        "CVE-2022-48940"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "68134668c17f31f51930478f75495b552a411550"
                },
                {
                  "fixed": "719d1c2524c89ada78c4c9202641c1d9e942a322"
                },
                {
                  "fixed": "eca9bd215d2233de79d930fa97aefbce03247a98"
                },
                {
                  "fixed": "a8abb0c3dc1e28454851a00f8b7333d9695d566c"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48940.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.15.0"
                },
                {
                  "fixed": "5.15.26"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.16.0"
                },
                {
                  "fixed": "5.16.12"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-48940.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.418329677Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/719d1c2524c89ada78c4c9202641c1d9e942a322",
        "https://git.kernel.org/stable/c/a8abb0c3dc1e28454851a00f8b7333d9695d566c",
        "https://git.kernel.org/stable/c/eca9bd215d2233de79d930fa97aefbce03247a98",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48940.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2022-48940",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/48xxx/CVE-2022-48940.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2022-48940",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 499314,
  "published_at": "2024-08-22T03:31:35.844+00:00"
}