{"id":"CVE-2026-64095","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64095","generatedAt":"2026-10-28T03:27:33.244Z","title":"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.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: bla: avoid double decrement of bla.num_requests\n\nThe bla.num_requests is increased when no request_sent was in progress. And\nit is decremented in various places (announcement was received, backbone is\npurged, periodic work). But the check if the request_sent is actually set\nto a specific state and the atomic_dec/_inc are not safe because they are\nnot atomic (TOCTOU) and multiple such code portions can run concurrently.\n\nAt the same time, it is necessary to modify request_sent (state) and\nbla.num_requests atomically. Otherwise batadv_bla_send_request() might set\nrequest_sent to 1 and is interrupted.  batadv_handle_announce() can then\nset request_sent back to 0 and decrement num_requests before\nbatadv_bla_send_request() incremented it.\n\nThe two operations must therefore be locked. And since state (request_sent)\nand wait_periods are only accessed inside this lock, they can be converted\nto simpler datatypes. And to avoid that the bla.num_requests is touched by\na parallel running context with a valid backbone_gw reference after\nbatadv_bla_purge_backbone_gw() ran, a third state \"stopped\" is required to\ncorrectly signal that a backbone_gw is in the state of being cleaned up.","published":"2026-07-19T16:17:50.000Z","lastModified":"2026-08-11T16:11:28.000Z","status":"Analyzed","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":7.1,"severity":"HIGH","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H"},"cwe":[],"affected":["linux/linux kernel"],"epss":{"score":0.00267,"percentile":0.18689,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.27%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/1f013bc94154f2e78e97d0296175664224c796e0","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/45384612f29692fbf0c770200361a7acff90125c","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/461f1e3dfb888701895b766446c55db2b10db705","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5328b95960774f2e189f22485616bc7b8eb2f7e3","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/65497ad155a3246df177b5ef662cd6e5a32cb470","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/83ab69bd12b80f6ea169c8bea6977701b53a043d","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/8ff9c59d1b7b48c2596878341a5310f32895d52b","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a9393751ecf7e9096f93cb6eed02db4f79125765","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64095","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}