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GHSA-RR6M-3X7M-QJFF

Vulnerability from github – Published: 2024-07-12 15:31 – Updated: 2025-11-04 00:30
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

ocfs2: fix races between hole punching and AIO+DIO

After commit "ocfs2: return real error code in ocfs2_dio_wr_get_block", fstests/generic/300 become from always failed to sometimes failed:

======================================================================== [ 473.293420 ] run fstests generic/300

[ 475.296983 ] JBD2: Ignoring recovery information on journal [ 475.302473 ] ocfs2: Mounting device (253,1) on (node local, slot 0) with ordered data mode. [ 494.290998 ] OCFS2: ERROR (device dm-1): ocfs2_change_extent_flag: Owner 5668 has an extent at cpos 78723 which can no longer be found [ 494.291609 ] On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted. [ 494.292018 ] OCFS2: File system is now read-only. [ 494.292224 ] (kworker/19:11,2628,19):ocfs2_mark_extent_written:5272 ERROR: status = -30 [ 494.292602 ] (kworker/19:11,2628,19):ocfs2_dio_end_io_write:2374 ERROR: status = -3 fio: io_u error on file /mnt/scratch/racer: Read-only file system: write offset=460849152, buflen=131072 =========================================================================

In __blockdev_direct_IO, ocfs2_dio_wr_get_block is called to add unwritten extents to a list. extents are also inserted into extent tree in ocfs2_write_begin_nolock. Then another thread call fallocate to puch a hole at one of the unwritten extent. The extent at cpos was removed by ocfs2_remove_extent(). At end io worker thread, ocfs2_search_extent_list found there is no such extent at the cpos.

T1                        T2                T3
                          inode lock
                            ...
                            insert extents
                            ...
                          inode unlock

ocfs2_fallocate __ocfs2_change_file_space inode lock lock ip_alloc_sem ocfs2_remove_inode_range inode ocfs2_remove_btree_range ocfs2_remove_extent ^---remove the extent at cpos 78723 ... unlock ip_alloc_sem inode unlock ocfs2_dio_end_io ocfs2_dio_end_io_write lock ip_alloc_sem ocfs2_mark_extent_written ocfs2_change_extent_flag ocfs2_search_extent_list ^---failed to find extent ... unlock ip_alloc_sem

In most filesystems, fallocate is not compatible with racing with AIO+DIO, so fix it by adding to wait for all dio before fallocate/punch_hole like ext4.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2024-40943"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-362"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2024-07-12T13:15:16Z",
    "severity": "MODERATE"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix races between hole punching and AIO+DIO\n\nAfter commit \"ocfs2: return real error code in ocfs2_dio_wr_get_block\",\nfstests/generic/300 become from always failed to sometimes failed:\n\n========================================================================\n[  473.293420 ] run fstests generic/300\n\n[  475.296983 ] JBD2: Ignoring recovery information on journal\n[  475.302473 ] ocfs2: Mounting device (253,1) on (node local, slot 0) with ordered data mode.\n[  494.290998 ] OCFS2: ERROR (device dm-1): ocfs2_change_extent_flag: Owner 5668 has an extent at cpos 78723 which can no longer be found\n[  494.291609 ] On-disk corruption discovered. Please run fsck.ocfs2 once the filesystem is unmounted.\n[  494.292018 ] OCFS2: File system is now read-only.\n[  494.292224 ] (kworker/19:11,2628,19):ocfs2_mark_extent_written:5272 ERROR: status = -30\n[  494.292602 ] (kworker/19:11,2628,19):ocfs2_dio_end_io_write:2374 ERROR: status = -3\nfio: io_u error on file /mnt/scratch/racer: Read-only file system: write offset=460849152, buflen=131072\n=========================================================================\n\nIn __blockdev_direct_IO, ocfs2_dio_wr_get_block is called to add unwritten\nextents to a list.  extents are also inserted into extent tree in\nocfs2_write_begin_nolock.  Then another thread call fallocate to puch a\nhole at one of the unwritten extent.  The extent at cpos was removed by\nocfs2_remove_extent().  At end io worker thread, ocfs2_search_extent_list\nfound there is no such extent at the cpos.\n\n    T1                        T2                T3\n                              inode lock\n                                ...\n                                insert extents\n                                ...\n                              inode unlock\nocfs2_fallocate\n __ocfs2_change_file_space\n  inode lock\n  lock ip_alloc_sem\n  ocfs2_remove_inode_range inode\n   ocfs2_remove_btree_range\n    ocfs2_remove_extent\n    ^---remove the extent at cpos 78723\n  ...\n  unlock ip_alloc_sem\n  inode unlock\n                                       ocfs2_dio_end_io\n                                        ocfs2_dio_end_io_write\n                                         lock ip_alloc_sem\n                                         ocfs2_mark_extent_written\n                                          ocfs2_change_extent_flag\n                                           ocfs2_search_extent_list\n                                           ^---failed to find extent\n                                          ...\n                                          unlock ip_alloc_sem\n\nIn most filesystems, fallocate is not compatible with racing with AIO+DIO,\nso fix it by adding to wait for all dio before fallocate/punch_hole like\next4.",
  "id": "GHSA-rr6m-3x7m-qjff",
  "modified": "2025-11-04T00:30:54Z",
  "published": "2024-07-12T15:31:28Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-40943"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/050ce8af6838c71e872e982b50d3f1bec21da40e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/117b9c009b72a6c2ebfd23484354dfee2d9570d2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/38825ff9da91d2854dcf6d9ac320a7e641e10f25"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3c26b5d21b1239e9c7fd31ba7d9b2d7bdbaa68d9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3c361f313d696df72f9bccf058510e9ec737b9b1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/952b023f06a24b2ad6ba67304c4c84d45bea2f18"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e8e2db1adac47970a6a9225f3858e9aa0e86287f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ea042dc2bea19d72e37c298bf65a9c341ef3fff3"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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