{"id":"CVE-2026-31657","title":"batman-adv: hold claim backbone gateways by reference","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: hold claim backbone gateways by reference\n\nbatadv_bla_add_claim() can replace claim->backbone_gw and drop the old\ngateway's last reference while readers sti…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 5202f071b367ffbc8e279fc7a00db14f5e587f52","Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 69d1ce9c72eca91203ffdb8d08bacd511100aec6","Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < f4858832ddef2f39f21e30b7226bbcd3c4b2bc96","Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 2f55b58b5a0bbed192d60c444a45a49cdf1b545f","Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 7962b522222628596ca9ecc8722efc95367aadbd","Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 4dee4c0688443aaf5bbec74aa203c851d1d53c35","Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 1f2dc36c297d27733f1b380ea644cf15a361bd7b","Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 82d8701b2c930d0e96b0dbc9115a218d791cb0d2","Linux 3.5"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"total","timestamp":"2026-10-16T15:11:37.875669Z"},"published":"2026-04-24","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:20:19.812Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31657","references":[{"url":"https://git.kernel.org/stable/c/5202f071b367ffbc8e279fc7a00db14f5e587f52"},{"url":"https://git.kernel.org/stable/c/69d1ce9c72eca91203ffdb8d08bacd511100aec6"},{"url":"https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96"},{"url":"https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f"},{"url":"https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd"},{"url":"https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35"},{"url":"https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b"},{"url":"https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2"}],"tags":["cve.org"],"epss":0.00399,"epssPercentile":0.32547,"ingestedAt":"2026-10-16T17:24:46.667Z","slug":"CVE-2026-31657","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbatman-adv: hold claim backbone gateways by reference\n\nbatadv_bla_add_claim() can replace claim->backbone_gw and drop the old\ngateway's last reference while readers still follow the pointer.\n\nThe netlink claim dump path dereferences claim->backbone_gw->orig and\ntakes claim->backbone_gw->crc_lock without pinning the underlying\nbackbone gateway. batadv_bla_check_claim() still has the same naked\npointer access pattern.\n\nReuse batadv_bla_claim_get_backbone_gw() in both readers so they operate\non a stable gateway reference until the read-side work is complete.\nThis keeps the dump and claim-check paths aligned with the lifetime\nrules introduced for the other BLA claim readers.\n\n## Affected\n\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 5202f071b367ffbc8e279fc7a00db14f5e587f52`\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 69d1ce9c72eca91203ffdb8d08bacd511100aec6`\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < f4858832ddef2f39f21e30b7226bbcd3c4b2bc96`\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 2f55b58b5a0bbed192d60c444a45a49cdf1b545f`\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 7962b522222628596ca9ecc8722efc95367aadbd`\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 4dee4c0688443aaf5bbec74aa203c851d1d53c35`\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 1f2dc36c297d27733f1b380ea644cf15a361bd7b`\n- `Linux >= 23721387c409087fd3b97e274f34d3ddc0970b74 < 82d8701b2c930d0e96b0dbc9115a218d791cb0d2`\n- `Linux 3.5`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}