CVE-2026-98682

Status: ReceivedUnscored—
Severity—Unscored
Exploitation probability0.15 %higher than 4% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

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.

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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.

CVSS

NVD hasn't assigned a CVSS score to this CVE (common since the April 2026 policy change).

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.15 %
Percentile among all scored CVEs
4
Score date
10/20/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

References

Show 2 references

Raw JSON (NVD)

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{
  "id": "CVE-2026-98682",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "c54fc3a4f375663f2361a9cbb2955fb4ef912879",
              "lessThan": "dc71660f11ef2fecc0695a41e49cd496a9d255ab",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "c54fc3a4f375663f2361a9cbb2955fb4ef912879",
              "lessThan": "c9b1194e8ec99d95db25db45edd2fbf690f043ab",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "358bd5f436d820bb758833050aae065b35d6986c",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "43801359c8971cc49b4a4db5015fba77fbd09c32",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "6.1.68",
              "lessThan": "6.2",
              "versionType": "semver"
            },
            {
              "status": "affected",
              "version": "6.6.7",
              "lessThan": "6.7",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "fs/smb/client/cifsfs.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "6.7",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver",
              "lessThanOrEqual": "7.2.*"
            },
            {
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "fs/smb/client/cifsfs.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-10-18T16:17:21.557",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/c9b1194e8ec99d95db25db45edd2fbf690f043ab",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/dc71660f11ef2fecc0695a41e49cd496a9d255ab",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "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's\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's 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's 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."
    }
  ],
  "lastModified": "2026-10-19T10:19:32.627",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}