ksmbd: fix use-after-free of fp->owner.name in durable handle owner check

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-72381
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-15 06:22:11 UTC
Updated2026-08-17 06:18:42 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of fp->owner.name in durable handle owner check Two concurrent SMB2 durable reconnects (DH2C/DHnC) on the same persistent_id race the fp->owner.name compare-read in ksmbd_vfs_compare_durable_owner() against the kfree() in ksmbd_reopen_durable_fd()'s reopen-success path. fp->owner.name is a standalone kstrdup() buffer whose lifetime is independent of the fp refcount, and the two sites share no lock: the compare reads the buffer while the reopen frees it, so the strcmp() can dereference freed memory. Commit 7ce4fc40018d ("ksmbd: fix durable reconnect double-bind race in ksmbd_reopen_durable_fd") made the fp->conn claim atomic under global_ft.lock (closing the owner.name double-free and the ksmbd_file write-UAF), but the compare-read versus reopen-free pair was left unserialized. BUG: KASAN: slab-use-after-free in strcmp+0x2c/0x80 Read of size 1 by task kworker strcmp ksmbd_vfs_compare_durable_owner smb2_check_durable_oplock smb2_open Freed by task kworker: kfree ksmbd_reopen_durable_fd smb2_open Allocated by task kworker: kstrdup session_fd_check smb2_session_logoff The buggy address belongs to the cache kmalloc-8 Serialize both sides of the race with fp->f_lock. The global durable file-table lock still protects the durable reconnect claim, but fp->owner.name is per-open state and does not need to block unrelated durable table lookups or reconnects. The teardown is left at its existing location after the reopen-success point so that an __open_id() rollback still retains owner.name for a later legitimate reconnect to verify.

Risk And Classification

Primary CVSS: v3.1 9.8 CRITICAL from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS: 0.006520000 probability, percentile 0.482820000 (date 2026-08-17)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
3.1CNADECLARED9.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 712cdf917e77a6444ce3836874829d770db20ee6 fb978d72052704c6b06c6b0f129fcd60b77169f5 git Not specified
CNA Linux Linux affected c7f0f0d01c88bdcb8b1694d7d321670013f7ed7d 93d4d46bf9d442a12ea87278049ec416962c627f git Not specified
CNA Linux Linux affected 00ce8d6789dae72d042a4522264964c72891ca37 5a5ac2852cd326529d02f778bc1aa6184701f4d7 git Not specified
CNA Linux Linux affected 49110a8ce654bbe56bef7c5e44cce31f4b102b8a ed98719be41389d416953b8ef9f07a07dfea6b2b git Not specified
CNA Linux Linux affected 49110a8ce654bbe56bef7c5e44cce31f4b102b8a 38637163501fd9e2f684b8cd275d0db5d79f37c6 git Not specified
CNA Linux Linux affected c908c853f304a4969b5aa10eba0b50350cc65b80 git Not specified
CNA Linux Linux affected 6.6.142 6.6.145 semver Not specified
CNA Linux Linux affected 6.12.92 6.12.97 semver Not specified
CNA Linux Linux affected 6.18.25 6.18.40 semver Not specified
CNA Linux Linux affected 7.0.2 7.1 semver Not specified
CNA Linux Linux affected 7.1 Not specified
CNA Linux Linux unaffected 7.1 semver Not specified
CNA Linux Linux unaffected 6.6.145 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.97 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.40 6.18.* semver Not specified
CNA Linux Linux unaffected 7.1.5 7.1.* semver Not specified
CNA Linux Linux unaffected 7.2 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/38637163501fd9e2f684b8cd275d0db5d79f37c6 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/ed98719be41389d416953b8ef9f07a07dfea6b2b 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/93d4d46bf9d442a12ea87278049ec416962c627f 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/fb978d72052704c6b06c6b0f129fcd60b77169f5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/5a5ac2852cd326529d02f778bc1aa6184701f4d7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report