cgroup/dmem: fix NULL pointer dereference when setting max

{
  "id": "81c8df058480a679eb9847bc2db756279696e62406af6618ef92beb047d4b80f",
  "url": "https://osv.dev/vulnerability/CVE-2026-23183",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "cgroup/dmem: fix NULL pointer dereference when setting max",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: cgroup/dmem: fix NULL pointer dereference when setting max An issue was triggered: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 15 UID: 0 PID: 658 Comm: bash Tainted: 6.19.0-rc6-next-2026012 Tainted: [O]=OOT_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), RIP: 0010:strcmp+0x10/0x30 RSP: 0018:ffffc900017f7dc0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888107cd4358 RDX: 0000000019f73907 RSI: ffffffff82cc381a RDI: 0000000000000000 RBP: ffff8881016bef0d R08: 000000006c0e7145 R09: 0000000056c0e714 R10: 0000000000000001 R11: ffff888107cd4358 R12: 0007ffffffffffff R13: ffff888101399200 R14: ffff888100fcb360 R15: 0007ffffffffffff CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000105c79000 CR4: 00000000000006f0 Call Trace: dmemcg_limit_write.constprop.0+0x16d/0x390 ? __pfx_set_resource_max+0x10/0x10 kernfs_fop_write_iter+0x14e/0x200 vfs_write+0x367/0x510 ksys_write+0x66/0xe0 do_syscall_64+0x6b/0x390 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f42697e1887 It was trriggered setting max without limitation, the command is like: \"echo test/region0 > dmem.max\". To fix this issue, add check whether options is valid after parsing the region_name.",
    "evidence": "osv:CVE-2026-23183",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-23183",
      "aliases": [
        "CVE-2026-23183"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "b168ed458ddecc176f3b9a1f4bcd83d7a4541c14"
                },
                {
                  "fixed": "c13816e8fa23deec6a8d7465d9e637fd02683b5c"
                },
                {
                  "fixed": "43151f812886be1855d2cba059f9c93e4729460b"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23183.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.14.0"
                },
                {
                  "fixed": "6.18.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23183.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.390784757Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/43151f812886be1855d2cba059f9c93e4729460b",
        "https://git.kernel.org/stable/c/c13816e8fa23deec6a8d7465d9e637fd02683b5c",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23183.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-23183",
        "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/2026/23xxx/CVE-2026-23183.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-23183",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 489821,
  "published_at": "2026-02-14T16:27:13.482+00:00"
}