CVE-2026-80926

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Source

https://cve.org/CVERecord?id=CVE-2026-80926

Import Source

https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80926.json

JSON Data

https://api.osv.dev/v1/vulns/CVE-2026-80926

Downstream

Related

openSUSE-SU-2026:11805-1

Published

2026-09-11T19:37:29Z

Modified

2026-10-24T02:30:28Z

Severity

9.8 (Critical) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator

Summary

ksmbd: fix use-after-free in oplock break notification

Details

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

ksmbd: fix use-after-free in oplock break notification

smb2_oplock_break_noti() reads opinfo->conn without any lock and dereferences it after two allocations which may sleep. When the durable handle owning the oplock is disconnected, session_fd_check() clears opinfo->conn and drops its conn reference under ci->m_lock, and the last ksmbd_conn_put() frees the connection. A break triggered by another connection that races with the teardown can then resurrect the freed connection: ksmbd_conn_get() is a plain atomic_inc, and the queued break work later dereferences the stale conn via ksmbd_conn_write(), a use-after-free reachable by any authenticated client holding a durable batch oplock.

Thread the caller's inode into the notification path instead of taking a new reference on it. Every caller of oplock_break() already holds a live ksmbd_file (or an explicit ksmbd_inode_lookup_lock() reference, in the parent lease break paths) on the inode that owns the break target's oplock list, so ci cannot be freed during the call, and its lock can be taken without dereferencing opinfo->o_fp, which a concurrent close may free. Select and pin the connection under ci->m_lock, the same lock session_fd_check() and ksmbd_reopen_durable_fd() use to update opinfo->conn, so a concurrent detach either loses the race to the clear or keeps the connection alive until the notification work releases it. Transfer the reference to the work item and release it on allocation failures.

Database specific

{
    "cna_assigner":  "Linux",
    "osv_generated_from":  "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80926.json"
}

References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

945a86b21b40fb17183f5b27461baa6f03e2467f

Fixed

892f643b141aee3f7aa7c0fc61ddcb55c59f1996

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

1ff58dcfcab434ebb51649da33774fbb8e1f7b67

Fixed

5de0527f782430b1109a447646e32033ad018a6a

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

e735dbd489e3ea02be78dba991056fe1138be51e

Fixed

c8279ae8df68cce9cd3b785e85f7a86c80a46e78

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

b003086d76968298f22e7cf62239833b5a3a06b1

Fixed

8cc98db4fc590e6c7d9db6529320982ee16c5d1d

Fixed

0e753899627b5e28a9fea8bca98262a6f65a2452

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

6.6.143

Fixed

6.6.158

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

6.12.94

Fixed

6.12.111

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

6.18.36

Fixed

6.18.51

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

7.0.13

Fixed

7.1

Type: GIT
Repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events: Introduced

75e33deda658c1ab3a9336cbdb1436536f9b3660

Affected versions

v6.*

v6.12.100

v6.12.101

v6.12.102

v6.12.103

v6.12.104

v6.12.105

v6.12.106

v6.12.107

v6.12.108

v6.12.109

v6.12.110

v6.12.94

v6.12.95

v6.12.96

v6.12.97

v6.12.98

v6.12.99

v6.18.36

v6.18.37

v6.18.38

v6.18.39

v6.18.40

v6.18.41

v6.18.42

v6.18.43

v6.18.44

v6.18.45

v6.18.46

v6.18.47

v6.18.48

v6.18.49

v6.18.50

v6.6.143

v6.6.144

v6.6.145

v6.6.146

v6.6.147

v6.6.148

v6.6.149

v6.6.150

v6.6.151

v6.6.152

v6.6.153

v6.6.154

v6.6.155

v6.6.156

v6.6.157

v7.*

v7.0.13

v7.0.14

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80926.json"

Linux / Kernel

Package

Name: Kernel

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

6.6.158

Type: ECOSYSTEM
Events: Introduced

6.7.0

Fixed

6.12.111

Type: ECOSYSTEM
Events: Introduced

6.13.0

Fixed

6.18.51

Type: ECOSYSTEM
Events: Introduced

6.19.0

Fixed

7.2.5

Database specific

source

"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80926.json"