{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "391e69143d0a05f960e3ab39a8c26b7b230bb8a9"
            },
            {
              "fixed": "c5908160e17cb56e1f61fbaee08adc21083f4933"
            },
            {
              "fixed": "de8016fb0904d68ac886e375069535996baa42ee"
            },
            {
              "fixed": "2b4331c08c0b385598b4d8ccd71e93ab3f4b2578"
            },
            {
              "fixed": "452894005b4abe141b11fe01e7bfe152e6d3860f"
            },
            {
              "fixed": "365c36e1a126c6aa1aecedd3a351bcabc66f0c29"
            },
            {
              "fixed": "3fd0685d7fef68c2d8a04876bcf9eaa0724ad6a5"
            },
            {
              "fixed": "b7f5ecd13cce8c2f8fa5a84c9aab65997142577e"
            },
            {
              "fixed": "ad9011a795407093dcf507f6e5da1828987b4b47"
            },
            {
              "fixed": "e9418da50d9e5c496c22fe392e4ad74c038a94eb"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.2.0"
            },
            {
              "fixed": "5.10.258"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.11.0"
            },
            {
              "fixed": "5.15.209"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.175"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.136"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.83"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.24"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.14"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.20.0"
            },
            {
              "fixed": "7.0.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31602.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: ctxfi: Limit PTP to a single page\n\nCommit 391e69143d0a increased CT_PTP_NUM from 1 to 4 to support 256\nplayback streams, but the additional pages are not used by the card\ncorrectly. The CT20K2 hardware already has multiple VMEM_PTPAL\nregisters, but using them separately would require refactoring the\nentire virtual memory allocation logic.\n\nct_vm_map() always uses PTEs in vm-\u003eptp[0].area regardless of\nCT_PTP_NUM. On AMD64 systems, a single PTP covers 512 PTEs (2M). When\naggregate memory allocations exceed this limit, ct_vm_map() tries to\naccess beyond the allocated space and causes a page fault:\n\n  BUG: unable to handle page fault for address: ffffd4ae8a10a000\n  Oops: Oops: 0002 [#1] SMP PTI\n  RIP: 0010:ct_vm_map+0x17c/0x280 [snd_ctxfi]\n  Call Trace:\n  atc_pcm_playback_prepare+0x225/0x3b0\n  ct_pcm_playback_prepare+0x38/0x60\n  snd_pcm_do_prepare+0x2f/0x50\n  snd_pcm_action_single+0x36/0x90\n  snd_pcm_action_nonatomic+0xbf/0xd0\n  snd_pcm_ioctl+0x28/0x40\n  __x64_sys_ioctl+0x97/0xe0\n  do_syscall_64+0x81/0x610\n  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nRevert CT_PTP_NUM to 1. The 256 SRC_RESOURCE_NUM and playback_count\nremain unchanged.",
  "id": "CVE-2026-31602",
  "modified": "2026-07-08T05:38:17.904303861Z",
  "published": "2026-04-24T14:42:25.935Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2b4331c08c0b385598b4d8ccd71e93ab3f4b2578"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/365c36e1a126c6aa1aecedd3a351bcabc66f0c29"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3fd0685d7fef68c2d8a04876bcf9eaa0724ad6a5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/452894005b4abe141b11fe01e7bfe152e6d3860f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ad9011a795407093dcf507f6e5da1828987b4b47"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b7f5ecd13cce8c2f8fa5a84c9aab65997142577e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c5908160e17cb56e1f61fbaee08adc21083f4933"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de8016fb0904d68ac886e375069535996baa42ee"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e9418da50d9e5c496c22fe392e4ad74c038a94eb"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31602.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31602"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.7.5",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ALSA: ctxfi: Limit PTP to a single page"
}