smb: client: protect tc_count increment in smb2_find_smb_sess_tcon_unlocked()
Published Jul 19, 2026
9.8
CRITICALCVSS 3.1
EPSS 0.67%
Description
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().
Affected products
-
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints-
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version
-
- Version 6.12.75StatusaffectedConstraints<6.12.92
- Version 6.18.16StatusaffectedConstraints<6.18.34
- Version 6.19.6StatusaffectedConstraints<6.20
- Version 6.6.128StatusaffectedConstraints<6.6.142
- Version
-
- Version 7.0StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<7.0
- Version 6.12.92StatusunaffectedConstraints<=6.12.*
- Version 6.18.34StatusunaffectedConstraints<=6.18.*
- Version 6.6.142StatusunaffectedConstraints<=6.6.*
- Version 7.0.11StatusunaffectedConstraints<=7.0.*
- Version 7.1StatusunaffectedConstraints<=*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
| ||||||||||||||||||||||||
| Linux | Linux | unaffected |
| ||||||||||||||||||||||||
| Linux | Linux | affected |
|
- ≥ 6.6.128 · < 6.6.142
- ≥ 6.12.75 · < 6.12.92
- ≥ 6.18.16 · < 6.18.34
- ≥ 6.19.6 · < 7.0.11
- 7.1
- 7.1
- 7.1
- 7.1
No data.
Red Hat Enterprise Linux 10
kernel-0:6.12.0-211.50.1.el10_2
Fixed · RHSA-2026:61887
Red Hat Enterprise Linux 9
kernel-0:5.14.0-687.45.1.el9_8
Fixed · RHSA-2026:64808
Red Hat Enterprise Linux 9
kernel-0:5.14.0-687.45.1.el9_8
Fixed · RHSA-2026:64808
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise Linux 9
kernel-rt
Affected
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel-0:6.12.0-211.50.1.el10_2 | Fixed | RHSA-2026:61887 |
| Red Hat Enterprise Linux 9 | kernel-0:5.14.0-687.45.1.el9_8 | Fixed | RHSA-2026:64808 |
| Red Hat Enterprise Linux 9 | kernel-0:5.14.0-687.45.1.el9_8 | Fixed | RHSA-2026:64808 |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Affected | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
References (10)
- https://access.redhat.com/security/cve/CVE-2026-64136 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2502527 Issue Tracking
- https://git.kernel.org/stable/c/13fb413ae22a37c69341918a6d651d19a9b0b9b7 Patch
- https://git.kernel.org/stable/c/4d8690dace005a38e6dbde9ecce2da3ad85c7c41 Patch
- https://git.kernel.org/stable/c/7df1df6f40c0720d30206aa35c0343b962350e0d Patch
- https://git.kernel.org/stable/c/bf4ebdb19ff9b3cdf992b50715fe61633327416a Patch
- https://git.kernel.org/stable/c/e374f4e496fef8168784f93a4477d67be34485fd Patch
- https://lore.kernel.org/linux-cve-announce/2026071928-CVE-2026-64136-5fb4@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2026-64136
- https://www.cve.org/CVERecord?id=CVE-2026-64136
Change history (0)
No recorded changes yet.