{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-31657", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-03-09T15:48:24.129Z", "datePublished": "2026-04-24T14:45:08.867Z", "dateUpdated": "2026-04-24T14:45:08.867Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-04-24T14:45:08.867Z"}, "descriptions": [{"lang": "en", "value": "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 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."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/batman-adv/bridge_loop_avoidance.c"], "versions": [{"version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "f4858832ddef2f39f21e30b7226bbcd3c4b2bc96", "status": "affected", "versionType": "git"}, {"version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "2f55b58b5a0bbed192d60c444a45a49cdf1b545f", "status": "affected", "versionType": "git"}, {"version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "7962b522222628596ca9ecc8722efc95367aadbd", "status": "affected", "versionType": "git"}, {"version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "4dee4c0688443aaf5bbec74aa203c851d1d53c35", "status": "affected", "versionType": "git"}, {"version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "1f2dc36c297d27733f1b380ea644cf15a361bd7b", "status": "affected", "versionType": "git"}, {"version": "23721387c409087fd3b97e274f34d3ddc0970b74", "lessThan": "82d8701b2c930d0e96b0dbc9115a218d791cb0d2", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["net/batman-adv/bridge_loop_avoidance.c"], "versions": [{"version": "3.5", "status": "affected"}, {"version": "0", "lessThan": "3.5", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.169", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.135", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.82", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.23", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.19.13", "lessThanOrEqual": "6.19.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.0", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix"}]}], "cpeApplicability": [{"nodes": [{"operator": "OR", "negate": false, "cpeMatch": [{"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.1.169"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.6.135"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.12.82"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.18.23"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.19.13"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "7.0"}]}]}], "references": [{"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"}], "title": "batman-adv: hold claim backbone gateways by reference", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "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 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."}], "id": "CVE-2026-31657", "lastModified": "2026-04-24T17:51:40.810", "metrics": {}, "published": "2026-04-24T15:16:45.227", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/1f2dc36c297d27733f1b380ea644cf15a361bd7b"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2f55b58b5a0bbed192d60c444a45a49cdf1b545f"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/4dee4c0688443aaf5bbec74aa203c851d1d53c35"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/7962b522222628596ca9ecc8722efc95367aadbd"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/82d8701b2c930d0e96b0dbc9115a218d791cb0d2"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/f4858832ddef2f39f21e30b7226bbcd3c4b2bc96"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Awaiting Analysis"}

{"bugzilla": {"description": "kernel: batman-adv: hold claim backbone gateways by reference", "id": "2461519", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2461519"}, "csaw": false, "cwe": "CWE-825", "details": ["A flaw was found in the Linux kernel's batman-adv component. The batadv_bla_add_claim() function can improperly drop a reference to a backbone gateway while other parts of the code, such as the netlink claim dump path, still hold and attempt to use a pointer to the freed memory. This creates a use-after-free vulnerability, which could allow a local attacker to cause system instability or a denial of service (DoS)."], "name": "CVE-2026-31657", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-04-24T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-31657\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-31657\nhttps://lore.kernel.org/linux-cve-announce/2026042402-CVE-2026-31657-fbab@gregkh/T"]}

{}