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ksmbd: defer publishing granted locks to prevent UAF/double-free race

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: ksmbd: defer publishing granted locks to prevent UAF/double-free race In smb2_lock(), mid-batch granted locks are published to connection-wide (conn->lock_list) and file-wide (fp->lock_list) lists immediately upon vfs_lock_file() success, while also remaining tracked on the stack-local rollback_list. If a subsequent element in the same SMB2_LOCK request array fails validation or execution, the thread jumps to out: and walks rollback_list to undo previously granted locks. However, because the granted lock was already published to conn->lock_list, a concurrent UNLOCK request on the same connection can find the lock object and kfree() it before the rollback loop executes. When the granting thread subsequently walks rollback_list, it dereferences and frees the already-freed ksmbd_lock structure, resulting in a Use-After-Free and Double-Free (on both ksmbd_lock and struct file_lock). Fix this by deferring the publication of granted locks to conn->lock_list and fp->lock_list until after the entire array of lock elements has been processed without error. Mid-batch grants remain tracked exclusively on the request-local rollback_list until the whole batch succeeds, eliminating the race window.

Announced Source revision 1
Original source ↗

CVE-2026-90162

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-90162

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
        "lessThan": "b68d4bb6b03a667c305626bd2c242fd162bac17e",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
        "lessThan": "65f54ed0289e9a57e6c60b14347ccea4c318f1fc",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
        "lessThan": "ff6870cf3b7eccc69d03cbb6f23e3995d96e9a8d",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
        "lessThan": "a1d26dfb32919088e3638dca01068df3c4507433",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "e2f34481b24db2fd634b5edb0a5bd0e4d38cc6e9",
        "lessThan": "29f74f0f2e6df3b393b7b66e810136d0c64e3c59",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "fs/smb/server/smb2pdu.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "5.15"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "5.15",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.160",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.114",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.57",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.6",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/smb/server/smb2pdu.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-90162

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#48623 · Revision 1
Added to Heist Feed
Publisher date
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