{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-53401",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-53401"
  ],
  "published": "2026-07-19T12:02:32Z",
  "summary": "fbdev: omap2: fix use-after-free in omapfb_mmap",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nfbdev: omap2: fix use-after-free in omapfb_mmap\n\nomapfb_mmap() has a race condition with OMAPFB_SETUP_PLANE ioctl that\ncan lead to use-after-free:\n\nThe fb_mmap() entry point holds mm_lock but not lock (fb_info->lock),\nwhile ioctl handlers like OMAPFB_SETUP_PLANE hold lock but not mm_lock.\nThis allows concurrent execution.\n\nIn omapfb_mmap():\n1. rg = omapfb_get_mem_region(ofbi->region);      // Get old region ref\n2. start = omapfb_get_region_paddr(ofbi);          // Read from NEW region\n3. len = fix->smem_len;                             // Read from NEW region\n4. vm_iomap_memory(vma, start, len);               // Map NEW region memory\n5. atomic_inc(&rg->map_count);                      // Increment OLD region!\n\nConcurrently, OMAPFB_SETUP_PLANE can:\n- Reassign ofbi->region = new_rg\n- Update fix->smem_len\n- OMAPFB_SETUP_MEM then checks NEW region's map_count (0!) and frees it\n\nThis leaves userspace with a mapping to freed physical memory.\n\nThe fix is to read all required values (start, len) from the same\nregion reference (rg) that will have its map_count incremented,\npreventing the region from being freed while still mapped.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": null,
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-53401"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6eb6ebcc8590007ad59ddccc8b5f9201655b33f8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7958e67375aa111522086286bba13cfc0816ce8d"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-17T05:24:08Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - Exploitation requires local syscalls (mmap and OMAPFB ioctls) against /dev/fb*; there is no network, adjacent-wireless, or physical-device insertion path to this driver code.\nAC:L - The attacker fully controls both sides of the race by opening /dev/fb and running concurrent mmap and OMAPFB_SETUP_PLANE/OMAPFB_SETUP_MEM ioctl threads, with no conditions outside attacker influence required for success.\nPR:L - Exploitation requires only the ability to open the framebuffer character device and issue its ioctls, which on OMAP embedded/kiosk deployments is typically granted to a local application user (video group or equivalent), not real root.\nUI:N - No victim interaction is required; the attacker triggers the race entirely through their own threads operating on a framebuffer device they can already open.\nS:U - Impact is confined to escalating within the same OS security boundary (userspace gaining read/write access to freed kernel/DMA physical memory), not a VM escape or cross-guest boundary crossing.\nC:H - The use-after-free leaves userspace mapped to freed physical pages that can be reallocated with sensitive kernel or DMA data, enabling arbitrary memory disclosure.\nI:H - The stale userspace mapping provides writable access to freed physical memory, enabling corruption of subsequently allocated kernel or DMA buffers and potential control-flow hijacking.\nA:H - Use-after-free of DMA framebuffer memory can cause kernel oopses or panics when freed pages are reused, and the UAF itself constitutes a high availability impact even before full exploitation."
    }
  }
}