batman-adv: bla: avoid double decrement of bla.num_requests
Summary
| CVE | CVE-2026-64095 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-19 16:17:50 UTC |
| Updated | 2026-08-11 16:11:27 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: batman-adv: bla: avoid double decrement of bla.num_requests The bla.num_requests is increased when no request_sent was in progress. And it is decremented in various places (announcement was received, backbone is purged, periodic work). But the check if the request_sent is actually set to a specific state and the atomic_dec/_inc are not safe because they are not atomic (TOCTOU) and multiple such code portions can run concurrently. At the same time, it is necessary to modify request_sent (state) and bla.num_requests atomically. Otherwise batadv_bla_send_request() might set request_sent to 1 and is interrupted. batadv_handle_announce() can then set request_sent back to 0 and decrement num_requests before batadv_bla_send_request() incremented it. The two operations must therefore be locked. And since state (request_sent) and wait_periods are only accessed inside this lock, they can be converted to simpler datatypes. And to avoid that the bla.num_requests is touched by a parallel running context with a valid backbone_gw reference after batadv_bla_purge_backbone_gw() ran, a third state "stopped" is required to correctly signal that a backbone_gw is in the state of being cleaned up. |
Risk And Classification
Primary CVSS: v3.1 7.1 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
EPSS: 0.002670000 probability, percentile 0.187360000 (date 2026-08-02)
Problem Types: NVD-CWE-noinfo
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 7.1 | HIGH | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H |
| 3.1 | CNA | DECLARED | 7.1 | HIGH | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H |
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
LowAvailability
HighCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Operating System | Linux | Linux Kernel | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 1f013bc94154f2e78e97d0296175664224c796e0 git | Not specified |
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 5328b95960774f2e189f22485616bc7b8eb2f7e3 git | Not specified |
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 8ff9c59d1b7b48c2596878341a5310f32895d52b git | Not specified |
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 a9393751ecf7e9096f93cb6eed02db4f79125765 git | Not specified |
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 461f1e3dfb888701895b766446c55db2b10db705 git | Not specified |
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 45384612f29692fbf0c770200361a7acff90125c git | Not specified |
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 65497ad155a3246df177b5ef662cd6e5a32cb470 git | Not specified |
| CNA | Linux | Linux | affected 23721387c409087fd3b97e274f34d3ddc0970b74 83ab69bd12b80f6ea169c8bea6977701b53a043d git | Not specified |
| CNA | Linux | Linux | affected 3.5 | Not specified |
| CNA | Linux | Linux | unaffected 3.5 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.259 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.210 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.176 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.143 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.93 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.34 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.0.11 7.0.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/65497ad155a3246df177b5ef662cd6e5a32cb470 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/5328b95960774f2e189f22485616bc7b8eb2f7e3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/1f013bc94154f2e78e97d0296175664224c796e0 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/45384612f29692fbf0c770200361a7acff90125c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/83ab69bd12b80f6ea169c8bea6977701b53a043d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/461f1e3dfb888701895b766446c55db2b10db705 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/a9393751ecf7e9096f93cb6eed02db4f79125765 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| git.kernel.org/stable/c/8ff9c59d1b7b48c2596878341a5310f32895d52b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | Patch |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.