{"id":"AZL-104708","summary":"CVE-2026-97611 affecting package kernel 6.6.157.1-1","details":"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-\u003emask_array);\n\tif (old) {\n\t\t...\n\t\tcall_rcu(&old-\u003ercu, mask_array_rcu_cb);\n\t}\n\n\trcu_assign_pointer(tbl-\u003emask_array, new);\n\ncall_rcu() only waits for read-side critical sections already in flight.\ntbl-\u003emask_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.","modified":"2026-09-27T05:34:32Z","published":"2026-09-25T11:17:15Z","upstream":["CVE-2026-97611"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97611"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-104708.json"}}],"schema_version":"1.9.0"}