CVE-2026-64136: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()
In the Linux kernel, the following vulnerability has been resolved:
smb: client: protect tccount increment in smb2findsmbsesstconunlocked()
Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields") refactored cifs code to change cifstcpseslock for tclock around tccount changes.
There was missing lock around tccount increment inside smb2findsmbsesstconunlocked().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Patch 96c4af418586
Event History
Frequently Asked Questions
What is the severity of CVE-2026-64136?
CVE-2026-64136 has a severity rating of critical with a CVSS score of 9.8.
How does CVE-2026-64136 affect the Linux kernel?
CVE-2026-64136 affects the Linux kernel by allowing improper handling of tc_count increments in SMB sessions, which can lead to potential data exposure.
How do I fix CVE-2026-64136?
To fix CVE-2026-64136, update your Linux kernel to the latest version where this vulnerability has been patched.
What systems are vulnerable to CVE-2026-64136?
CVE-2026-64136 primarily affects systems running vulnerable versions of the Linux kernel that utilize SMB protocol.
What are the potential impacts of CVE-2026-64136?
The potential impact of CVE-2026-64136 includes unauthorized access to sensitive information due to improper memory management.