ghsa-m97q-c3xf-55xf
Vulnerability from github
Published
2025-10-01 12:30
Modified
2025-10-01 12:30
Details

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

io_uring: fix fget leak when fs don't support nowait buffered read

Heming reported a BUG when using io_uring doing link-cp on ocfs2. [1]

Do the following steps can reproduce this BUG: mount -t ocfs2 /dev/vdc /mnt/ocfs2 cp testfile /mnt/ocfs2/ ./link-cp /mnt/ocfs2/testfile /mnt/ocfs2/testfile.1 umount /mnt/ocfs2

Then umount will fail, and it outputs: umount: /mnt/ocfs2: target is busy.

While tracing umount, it blames mnt_get_count() not return as expected. Do a deep investigation for fget()/fput() on related code flow, I've finally found that fget() leaks since ocfs2 doesn't support nowait buffered read.

io_issue_sqe |-io_assign_file // do fget() first |-io_read |-io_iter_do_read |-ocfs2_file_read_iter // return -EOPNOTSUPP |-kiocb_done |-io_rw_done |-__io_complete_rw_common // set REQ_F_REISSUE |-io_resubmit_prep |-io_req_prep_async // override req->file, leak happens

This was introduced by commit a196c78b5443 in v5.18. Fix it by don't re-assign req->file if it has already been assigned.

[1] https://lore.kernel.org/ocfs2-devel/ab580a75-91c8-d68a-3455-40361be1bfa8@linux.alibaba.com/T/#t

Show details on source website


{
  "affected": [],
  "aliases": [
    "CVE-2023-53511"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-10-01T12:15:55Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix fget leak when fs don\u0027t support nowait buffered read\n\nHeming reported a BUG when using io_uring doing link-cp on ocfs2. [1]\n\nDo the following steps can reproduce this BUG:\nmount -t ocfs2 /dev/vdc /mnt/ocfs2\ncp testfile /mnt/ocfs2/\n./link-cp /mnt/ocfs2/testfile /mnt/ocfs2/testfile.1\numount /mnt/ocfs2\n\nThen umount will fail, and it outputs:\numount: /mnt/ocfs2: target is busy.\n\nWhile tracing umount, it blames mnt_get_count() not return as expected.\nDo a deep investigation for fget()/fput() on related code flow, I\u0027ve\nfinally found that fget() leaks since ocfs2 doesn\u0027t support nowait\nbuffered read.\n\nio_issue_sqe\n|-io_assign_file  // do fget() first\n  |-io_read\n  |-io_iter_do_read\n    |-ocfs2_file_read_iter  // return -EOPNOTSUPP\n  |-kiocb_done\n    |-io_rw_done\n      |-__io_complete_rw_common  // set REQ_F_REISSUE\n    |-io_resubmit_prep\n      |-io_req_prep_async  // override req-\u003efile, leak happens\n\nThis was introduced by commit a196c78b5443 in v5.18. Fix it by don\u0027t\nre-assign req-\u003efile if it has already been assigned.\n\n[1] https://lore.kernel.org/ocfs2-devel/ab580a75-91c8-d68a-3455-40361be1bfa8@linux.alibaba.com/T/#t",
  "id": "GHSA-m97q-c3xf-55xf",
  "modified": "2025-10-01T12:30:31Z",
  "published": "2025-10-01T12:30:30Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-53511"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/10fb2e16ee6ffaf1716b9e90d007e6b300bfa457"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/54aa7f2330b82884f4a1afce0220add6e8312f8b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/75a499fc9d66a32271e2b3e4ca71156e8ad3b484"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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