Bug 2502527 (CVE-2026-64136)
| Summary: | CVE-2026-64136 kernel: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security <prodsec-ir-bot> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | rhel-process-autobot, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's Server Message Block (SMB) client. A missing lock around the `tc_count` increment in the `smb2_find_smb_sess_tcon_unlocked()` function creates a race condition. This vulnerability, caused by an incomplete refactoring of locking mechanisms, could lead to unexpected behavior.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2026071928-CVE-2026-64136-5fb4@gregkh/T This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2026:61887 https://access.redhat.com/errata/RHSA-2026:61887 This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2026:64808 https://access.redhat.com/errata/RHSA-2026:64808 |
In the Linux kernel, the following vulnerability has been resolved: smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked() Commit 96c4af418586 ("cifs: Fix locking usage for tcon fields") refactored cifs code to change cifs_tcp_ses_lock for tc_lock around tc_count changes. There was missing lock around tc_count increment inside smb2_find_smb_sess_tcon_unlocked().