batman-adv: tt: fix TOCTOU race for reported vlans
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA.
Summary
In the Linux kernel, the following vulnerability has been resolved: batman-adv: tt: fix TOCTOU race for reported vlans The local TT based TVLV is generated by first checking the number of VLANs which have at least one TT entry. A new buffer with the correct size for the VLANs is then allocated. Only then, the list of VLANs s used to fill the VLAN entries in the buffer. During this time, the meshif_vlan_list_lock is held. But the actual number of TT entries of each VLAN can still increase during this time - just not the number of VLANs in the list. But the prefilter used in the buffer size calculation might still cause an increase of the number of VLANs which need to be stored. Simply because a VLAN might now suddenly have at least one entry when it had none in the pre-alloc check - and then needs to occupy space which was not allocated. It is better to overestimate the buffer size at the beginning and then fill the buffer only with the VLANs which are not empty.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 3.16.60 to before 3.17; 4.4.217 to before 4.5; 4.9.217 to before 4.10; 4.14.174 to before 4.15 | 3.17, 4.5, 4.10, 4.15 | Patch available | CNA |
| Linux | Linux | 4.17 and later | 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.34, 7.0.11, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 3.16.60 to before 3.17; 4.4.217 to before 4.5; 4.9.217 to before 4.10; 4.14.174 to before 4.15 Fixed in 3.17, 4.5, 4.10, 4.15 Patch available CNA
- Linux VendorLinux Affected 4.17 and later Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.34, 7.0.11, 7.1 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 3.16.60 to before 3.17; 4.4.217 to before 4.5; 4.9.217 to before 4.10; 4.14.174 to before 4.15; 4.17.1 to before 5.10.259; 5.11 to before 5.15.210; 5.16 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.93; 6.13 to before 6.18.34; 6.19 to before 7.0.11 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.17:-:*:*:*:*:*:* | 4.17 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:4.17:rc7:*:*:*:*:*:* | 4.17 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | 7.1 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | 7.1 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | 7.1 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | 7.1 rc4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.16.60 to before 3.17; 4.4.217 to before 4.5; 4.9.217 to before 4.10; 4.14.174 to before 4.15; 4.17.1 to before 5.10.259; 5.11 to before 5.15.210; 5.16 to before 6.1.176; 6.2 to before 6.6.143; 6.7 to before 6.12.93; 6.13 to before 6.18.34; 6.19 to before 7.0.11 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.17:-:*:*:*:*:*:* Versions 4.17 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:4.17:rc7:*:*:*:*:*:* Versions 4.17 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 3.17, 4.5, 4.10, 4.15
- Fix · CNA Linux (Linux) Fixed in 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.34, 7.0.11, 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 5 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64091
- 2026-10-03 Alias added: GHSA-r4m5-xwcp-9p7w
- 2026-10-20 Affected versions changed · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/e4236bf3ec8d6bb15d0d8d825dcf9933a7d6666b
- https://git.kernel.org/stable/c/724a8eb4155669797c96b70d70e354284ae3b5a8
- https://git.kernel.org/stable/c/211ea59988e1cba43cb0367ad65d379b56f9c3bd
- https://git.kernel.org/stable/c/65a1e67339aa8c95ac544b796946af388930ee23
- https://git.kernel.org/stable/c/b4d4efd4e351593c81e9293d4b4408d244fa5ee7
- https://git.kernel.org/stable/c/4cc85aec8d3c9ab4dc716dc9f1ed36fca16b227f
- https://git.kernel.org/stable/c/9a9c859457bc440a55773e01ff18b1bb5bab6836
- https://git.kernel.org/stable/c/94d27005016be15ffc638b2ecbc4d58805ad7b48
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Sources
- CVE-2026-64091 · CVE Program
- CVE-2026-64091 · NVD
- FIRST EPSS
- GHSA-r4m5-xwcp-9p7w · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64091 · Red Hat security data · CC BY 4.0
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