{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.176-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.94-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.0.10-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  ocfs2: validate bg_bits during freefrag scan  [BUG] A crafted filesystem can trigger an out-of-bounds bitmap walk when OCFS2_IOC_INFO is issued with OCFS2_INFO_FL_NON_COHERENT.  BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: use-after-free in test_bit_le include/asm-generic/bitops/le.h:21 [inline] BUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline] BUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline] BUG: KASAN: use-after-free in ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline] BUG: KASAN: use-after-free in ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754 Read of size 8 at addr ffff888031bce000 by task syz.0.636/1435 Call Trace:  __dump_stack lib/dump_stack.c:94 [inline]  dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120  print_address_description mm/kasan/report.c:378 [inline]  print_report+0xd1/0x650 mm/kasan/report.c:482  kasan_report+0xfb/0x140 mm/kasan/report.c:595  check_region_inline mm/kasan/generic.c:186 [inline]  kasan_check_range+0x11c/0x200 mm/kasan/generic.c:200  __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31  instrument_atomic_read include/linux/instrumented.h:68 [inline]  _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]  test_bit_le include/asm-generic/bitops/le.h:21 [inline]  ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline]  ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline]  ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline]  ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754  ocfs2_info_handle+0x18d/0x2a0 fs/ocfs2/ioctl.c:828  ocfs2_ioctl+0x632/0x6e0 fs/ocfs2/ioctl.c:913  vfs_ioctl fs/ioctl.c:51 [inline]  __do_sys_ioctl fs/ioctl.c:597 [inline]  __se_sys_ioctl fs/ioctl.c:583 [inline]  __x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583  ...  [CAUSE] ocfs2_info_freefrag_scan_chain() uses on-disk bg_bits directly as the bitmap scan limit. The coherent path reads group descriptors through ocfs2_read_group_descriptor(), which validates the descriptor before use. The non-coherent path uses ocfs2_read_blocks_sync() instead and skips that validation, so an impossible bg_bits value can drive the bitmap walk past the end of the block.  [FIX] Compute the bitmap capacity from the filesystem format with ocfs2_group_bitmap_size(), report descriptors whose bg_bits exceeds that limit, and clamp the scan to the computed capacity. This keeps the freefrag report going while avoiding reads beyond the buffer.",
  "id": "DEBIAN-CVE-2026-53040",
  "modified": "2026-09-14T16:47:31.145279780Z",
  "published": "2026-06-24T17:17:15.687Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-53040"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-53040"
  ]
}