{"api_version":"1","generated_at":"2026-10-01T19:08:52+00:00","cve":"CVE-2026-97611","urls":{"html":"https://cve.report/CVE-2026-97611","api":"https://cve.report/api/cve/CVE-2026-97611.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-97611","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-97611"},"summary":{"title":"net: openvswitch: fix use-after-free of the flow table mask array","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: fix use-after-free of the flow table mask array\n\ntbl_mask_array_realloc() retires the old mask_array before it stops being\nreachable:\n\n\told = ovsl_dereference(tbl->mask_array);\n\tif (old) {\n\t\t...\n\t\tcall_rcu(&old->rcu, mask_array_rcu_cb);\n\t}\n\n\trcu_assign_pointer(tbl->mask_array, new);\n\ncall_rcu() only waits for read-side critical sections already in flight.\ntbl->mask_array still points at old between the call_rcu() and the\nrcu_assign_pointer(), so a reader entering ovs_flow_tbl_lookup_stats() in\nthat window picks up old in a fresh critical section that the pending\ngrace period does not cover.\n\ntbl_mask_array_realloc() runs in process context under ovs_mutex, so the\nwindow is preemptible and can outlast the grace period. Then\nmask_array_rcu_cb() frees old before the swap runs:\n\n  BUG: KASAN: slab-use-after-free in flow_lookup.constprop.0+0x2bf/0x2f0\n  Read of size 8 at addr ffff888020b3e018 by task poc/741\n   flow_lookup.constprop.0+0x2bf/0x2f0\n   ovs_flow_tbl_lookup_stats+0x4a3/0x5c0\n   ovs_dp_process_packet+0x19c/0x710\n   ovs_vport_receive+0x243/0x390\n   internal_dev_xmit+0x81/0x170\n  Freed by task 728:\n   kfree+0x16a/0x4e0\n   rcu_core+0x853/0x1030\n\nPublish the new array before retiring the old one. The kfree_rcu() that\ncall_rcu() replaced ran after the swap.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-25 11:17:15","updated_at":"2026-09-25 15:18:01"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/a0d18d21d48a551f82ee344e50efb8a682161489","name":"https://git.kernel.org/stable/c/a0d18d21d48a551f82ee344e50efb8a682161489","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/cd982e11684def5d4a9fcfd5354de09032828414","name":"https://git.kernel.org/stable/c/cd982e11684def5d4a9fcfd5354de09032828414","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ba4ba11ed6eb8972c69070417fc27b48deb002e8","name":"https://git.kernel.org/stable/c/ba4ba11ed6eb8972c69070417fc27b48deb002e8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/035e9c3722067648a99010711d0ce81f42572ef4","name":"https://git.kernel.org/stable/c/035e9c3722067648a99010711d0ce81f42572ef4","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97611","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97611","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected eac87c413bf9794c14d488998a5265ea5b32f04e cd982e11684def5d4a9fcfd5354de09032828414 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected eac87c413bf9794c14d488998a5265ea5b32f04e a0d18d21d48a551f82ee344e50efb8a682161489 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected eac87c413bf9794c14d488998a5265ea5b32f04e 035e9c3722067648a99010711d0ce81f42572ef4 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected eac87c413bf9794c14d488998a5265ea5b32f04e ba4ba11ed6eb8972c69070417fc27b48deb002e8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.9","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.9 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.7 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"97611","cve":"CVE-2026-97611","epss":"0.001590000","percentile":"0.043090000","score_date":"2026-09-27","updated_at":"2026-09-28 00:02:23"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["net/openvswitch/flow_table.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"cd982e11684def5d4a9fcfd5354de09032828414","status":"affected","version":"eac87c413bf9794c14d488998a5265ea5b32f04e","versionType":"git"},{"lessThan":"a0d18d21d48a551f82ee344e50efb8a682161489","status":"affected","version":"eac87c413bf9794c14d488998a5265ea5b32f04e","versionType":"git"},{"lessThan":"035e9c3722067648a99010711d0ce81f42572ef4","status":"affected","version":"eac87c413bf9794c14d488998a5265ea5b32f04e","versionType":"git"},{"lessThan":"ba4ba11ed6eb8972c69070417fc27b48deb002e8","status":"affected","version":"eac87c413bf9794c14d488998a5265ea5b32f04e","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["net/openvswitch/flow_table.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.9"},{"lessThan":"5.9","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.111","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.7","versionStartIncluding":"5.9","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc3","versionStartIncluding":"5.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: fix use-after-free of the flow table mask array\n\ntbl_mask_array_realloc() retires the old mask_array before it stops being\nreachable:\n\n\told = ovsl_dereference(tbl->mask_array);\n\tif (old) {\n\t\t...\n\t\tcall_rcu(&old->rcu, mask_array_rcu_cb);\n\t}\n\n\trcu_assign_pointer(tbl->mask_array, new);\n\ncall_rcu() only waits for read-side critical sections already in flight.\ntbl->mask_array still points at old between the call_rcu() and the\nrcu_assign_pointer(), so a reader entering ovs_flow_tbl_lookup_stats() in\nthat window picks up old in a fresh critical section that the pending\ngrace period does not cover.\n\ntbl_mask_array_realloc() runs in process context under ovs_mutex, so the\nwindow is preemptible and can outlast the grace period. Then\nmask_array_rcu_cb() frees old before the swap runs:\n\n  BUG: KASAN: slab-use-after-free in flow_lookup.constprop.0+0x2bf/0x2f0\n  Read of size 8 at addr ffff888020b3e018 by task poc/741\n   flow_lookup.constprop.0+0x2bf/0x2f0\n   ovs_flow_tbl_lookup_stats+0x4a3/0x5c0\n   ovs_dp_process_packet+0x19c/0x710\n   ovs_vport_receive+0x243/0x390\n   internal_dev_xmit+0x81/0x170\n  Freed by task 728:\n   kfree+0x16a/0x4e0\n   rcu_core+0x853/0x1030\n\nPublish the new array before retiring the old one. The kfree_rcu() that\ncall_rcu() replaced ran after the swap."}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - Both sides of the race are driven locally: tbl_mask_array_realloc() runs from OVS_FLOW_CMD_NEW/DEL generic-netlink requests (flow insert/remove growing or shrinking the mask array), and the reader is ovs_flow_tbl_lookup_stats() fed by the attacker's own packets via internal_dev_xmit. No remote protocol carries data that causes the bug.\nAC:L - The attacker controls both sides, looping flow add/delete to trigger reallocs while transmitting on the datapath's internal port so lookups run. Failed attempts are harmless, the preemptible window can outlast a grace period, and the reporter's KASAN trace shows a PoC hit it.\nPR:L - The OVS datapath, vport and flow genl ops are GENL_UNS_ADMIN_PERM with netnsok=true, so CAP_NET_ADMIN in a user namespace (unshare -Urn) is enough to create a datapath, add flows and send packets through it.\nUI:N - No victim action is needed; the attacker creates the datapath, drives mask-array reallocation and generates the lookup traffic entirely by themselves.\nS:U - The impact stays within the kernel's own security authority, as ordinary kernel memory corruption leading to local privilege escalation; no VM or hardware boundary is crossed.\nC:H - flow_lookup() reads the freed struct mask_array (max, masks[] pointers) and dereferences masks[i] as sw_flow_mask. If the slab is reclaimed with attacker data, that gives controlled-pointer reads of kernel memory.\nI:H - On a flow hit, flow_lookup() does stats->usage_cntrs[index]++ through ma->masks_usage_stats taken from the freed mask_array, so a reclaimed object yields an attacker-steered kernel memory increment (write primitive).\nA:H - The slab use-after-free in flow_lookup() during ovs_dp_process_packet crashes the kernel (KASAN-reported); with a reclaimed object, wild pointer dereferences cause an oops or panic."}]}],"providerMetadata":{"dateUpdated":"2026-09-25T14:41:33.156Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/cd982e11684def5d4a9fcfd5354de09032828414"},{"url":"https://git.kernel.org/stable/c/a0d18d21d48a551f82ee344e50efb8a682161489"},{"url":"https://git.kernel.org/stable/c/035e9c3722067648a99010711d0ce81f42572ef4"},{"url":"https://git.kernel.org/stable/c/ba4ba11ed6eb8972c69070417fc27b48deb002e8"}],"title":"net: openvswitch: fix use-after-free of the flow table mask array","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-97611","datePublished":"2026-09-25T10:22:20.827Z","dateReserved":"2026-09-24T16:01:01.158Z","dateUpdated":"2026-09-25T14:41:33.156Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-25 11:17:15","lastModifiedDate":"2026-09-25 15:18:01","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"97611","Ordinal":"1","Title":"net: openvswitch: fix use-after-free of the flow table mask arra","CVE":"CVE-2026-97611","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"97611","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: openvswitch: fix use-after-free of the flow table mask array\n\ntbl_mask_array_realloc() retires the old mask_array before it stops being\nreachable:\n\n\told = ovsl_dereference(tbl->mask_array);\n\tif (old) {\n\t\t...\n\t\tcall_rcu(&old->rcu, mask_array_rcu_cb);\n\t}\n\n\trcu_assign_pointer(tbl->mask_array, new);\n\ncall_rcu() only waits for read-side critical sections already in flight.\ntbl->mask_array still points at old between the call_rcu() and the\nrcu_assign_pointer(), so a reader entering ovs_flow_tbl_lookup_stats() in\nthat window picks up old in a fresh critical section that the pending\ngrace period does not cover.\n\ntbl_mask_array_realloc() runs in process context under ovs_mutex, so the\nwindow is preemptible and can outlast the grace period. Then\nmask_array_rcu_cb() frees old before the swap runs:\n\n  BUG: KASAN: slab-use-after-free in flow_lookup.constprop.0+0x2bf/0x2f0\n  Read of size 8 at addr ffff888020b3e018 by task poc/741\n   flow_lookup.constprop.0+0x2bf/0x2f0\n   ovs_flow_tbl_lookup_stats+0x4a3/0x5c0\n   ovs_dp_process_packet+0x19c/0x710\n   ovs_vport_receive+0x243/0x390\n   internal_dev_xmit+0x81/0x170\n  Freed by task 728:\n   kfree+0x16a/0x4e0\n   rcu_core+0x853/0x1030\n\nPublish the new array before retiring the old one. The kfree_rcu() that\ncall_rcu() replaced ran after the swap.","Type":"Description","Title":"net: openvswitch: fix use-after-free of the flow table mask arra"}]}}}