GHSA-78HR-GPP6-3QPR

Vulnerability from github – Published: 2026-10-18 18:31 – Updated: 2026-10-18 18:31
VLAI
Details

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

smb: client: drain and invalidate before server-side copy/clone

cifs_file_copychunk_range() and the clone (FICLONE) path of cifs_remap_file_range() do not serialise the destination page cache against the server-side copy the way the other server-side range operations (smb3_zero_range(), smb3_punch_hole(), smb3_collapse_range() and smb3_insert_range()) do.

cifs_file_copychunk_range() invalidates the destination range with filemap_invalidate_inode(), which takes and drops the mapping's invalidate_lock internally, so the lock is no longer held when the copychunk ioctl is issued. It also never drains in-flight netfs I/O on the target. The clone path never takes the invalidate_lock at all (only i_rwsem), uses a bare truncate_inode_pages_range() and likewise does not drain outstanding I/O.

As a result an asynchronous destination writeback can complete after the server-side copy/clone has run and reinstate stale data over the region just written by the server, corrupting the file. This is the same class of corruption as commit d7d2adcd022b ("smb/client: flush dirty data before punching a hole") and has been seen randomly in generic/363 against Windows Server.

Fix both paths to follow the established ordering: hold the target mapping's invalidate_lock across the flush and invalidation of the destination and the server ioctl, and call netfs_wait_for_outstanding_io() on the target to drain in-flight writes before the ioctl is issued. Only the target inode's invalidate_lock is required, as the source is merely flushed and not invalidated; i_rwsem (already held via lock_two_nondirectories()) is acquired before the invalidate_lock, matching the VFS lock ordering. Since filemap_invalidate_inode() takes that same lock internally, replace it with its own unmap/flush/invalidate steps instead of calling it, and return early on a zero-length copy to avoid a range underflow.

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-98682"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-18T16:17:21Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: client: drain and invalidate before server-side copy/clone\n\ncifs_file_copychunk_range() and the clone (FICLONE) path of\ncifs_remap_file_range() do not serialise the destination page cache\nagainst the server-side copy the way the other server-side range\noperations (smb3_zero_range(), smb3_punch_hole(), smb3_collapse_range()\nand smb3_insert_range()) do.\n\ncifs_file_copychunk_range() invalidates the destination range with\nfilemap_invalidate_inode(), which takes and drops the mapping\u0027s\ninvalidate_lock internally, so the lock is no longer held when the\ncopychunk ioctl is issued.  It also never drains in-flight netfs I/O on\nthe target.  The clone path never takes the invalidate_lock at all (only\ni_rwsem), uses a bare truncate_inode_pages_range() and likewise does not\ndrain outstanding I/O.\n\nAs a result an asynchronous destination writeback can complete after the\nserver-side copy/clone has run and reinstate stale data over the region\njust written by the server, corrupting the file.  This is the same class\nof corruption as commit d7d2adcd022b (\"smb/client: flush dirty data\nbefore punching a hole\") and has been seen randomly in generic/363\nagainst Windows Server.\n\nFix both paths to follow the established ordering: hold the target\nmapping\u0027s invalidate_lock across the flush and invalidation of the\ndestination and the server ioctl, and call netfs_wait_for_outstanding_io()\non the target to drain in-flight writes before the ioctl is issued.  Only\nthe target inode\u0027s invalidate_lock is required, as the source is merely\nflushed and not invalidated; i_rwsem (already held via\nlock_two_nondirectories()) is acquired before the invalidate_lock,\nmatching the VFS lock ordering.  Since filemap_invalidate_inode() takes\nthat same lock internally, replace it with its own unmap/flush/invalidate\nsteps instead of calling it, and return early on a zero-length copy to\navoid a range underflow.",
  "id": "GHSA-78hr-gpp6-3qpr",
  "modified": "2026-10-18T18:31:59Z",
  "published": "2026-10-18T18:31:59Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98682"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c9b1194e8ec99d95db25db45edd2fbf690f043ab"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/dc71660f11ef2fecc0695a41e49cd496a9d255ab"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON
Events included in the timeline

Loading timeline…


    Loading…

    Loading…

    Loading…

    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.