High 7.1Published Jul 19, 2026

CVE-2026-64095batman-adv: bla: avoid double decrement of bla.num_requests

Updated under an hour ago (Oct 26, 2026, 7:50 PM ET)

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Exploited in the last 30 days

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.

CVSS: 7.1 HIGH (v3.1, CNA)CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: Aug 5, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	23721387c409087fd3b97e274f34d3ddc0970b74 builds before 1f013bc94154f2e78e97d0296175664224c796e0; 23721387c409087fd3b97e274f34d3ddc0970b74 builds before 5328b95960774f2e189f22485616bc7b8eb2f7e3; 23721387c409087fd3b97e274f34d3ddc0970b74 builds before 8ff9c59d1b7b48c2596878341a5310f32895d52b; from 23721387c409087fd3b97e274f34d3ddc0970b74 before a9393751ecf7e9096f93cb6eed02db4f79125765; 23721387c409087fd3b97e274f34d3ddc0970b74 builds before 461f1e3dfb888701895b766446c55db2b10db705; from 23721387c409087fd3b97e274f34d3ddc0970b74 before 45384612f29692fbf0c770200361a7acff90125c; 23721387c409087fd3b97e274f34d3ddc0970b74 builds before 65497ad155a3246df177b5ef662cd6e5a32cb470; 23721387c409087fd3b97e274f34d3ddc0970b74 builds before 83ab69bd12b80f6ea169c8bea6977701b53a043d	CNA record
linux linux_kernel linux:linux_kernel	from 3.5 before 5.10.259; from 5.11 before 5.15.210; from 5.16 before 6.1.176; from 6.2 before 6.6.143; from 6.7 before 6.12.93; from 6.13 before 6.18.34; from 6.19 before 7.0.11; 7.1; and 3 more ranges	NVD

References

References

https://git.kernel.org/stable/c/1f013bc94154f2e78e97d0296175664224c796e0	patch
https://git.kernel.org/stable/c/5328b95960774f2e189f22485616bc7b8eb2f7e3	patch
https://git.kernel.org/stable/c/8ff9c59d1b7b48c2596878341a5310f32895d52b	patch
https://git.kernel.org/stable/c/a9393751ecf7e9096f93cb6eed02db4f79125765	patch
https://git.kernel.org/stable/c/461f1e3dfb888701895b766446c55db2b10db705	patch
https://git.kernel.org/stable/c/45384612f29692fbf0c770200361a7acff90125c	patch
https://git.kernel.org/stable/c/65497ad155a3246df177b5ef662cd6e5a32cb470	patch
https://git.kernel.org/stable/c/83ab69bd12b80f6ea169c8bea6977701b53a043d	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.