{"id":"CVE-2026-64115","title":"vsock/vmci: fix UAF when peer resets connection during handshake","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: fix UAF when peer resets connection during handshake\n\nvmci_transport_recv_connecting_server() returned err = 0 for a peer\nRST in its default switch arm:\n\n\te…","severity":"high","cvss":8.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","cvssSource":"cna","vendor":"Linux","product":"Linux","affected":["Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 1e19f08552b90070ed18bafb1763c78297823af6","Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 1dd531e28f61edd286edc486ab068f135b5ae1eb","Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < ecda37f8faab3220da199335e42564cb7a9ad145","Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb","Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9","Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 440447699c681e26ed58e9c309cad718270a18b4","Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 9fe74e42914c851d68069713b7b917a9c33faf26","Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 99e22ddf4edb63dc8382bc028af928056d3450cf","Linux 3.9"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-16T15:36:34.520586Z"},"published":"2026-07-19","updated":"2026-10-16","sourceUpdated":"2026-10-16T15:42:23.154Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-64115","references":[{"url":"https://git.kernel.org/stable/c/1e19f08552b90070ed18bafb1763c78297823af6"},{"url":"https://git.kernel.org/stable/c/1dd531e28f61edd286edc486ab068f135b5ae1eb"},{"url":"https://git.kernel.org/stable/c/ecda37f8faab3220da199335e42564cb7a9ad145"},{"url":"https://git.kernel.org/stable/c/cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb"},{"url":"https://git.kernel.org/stable/c/47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9"},{"url":"https://git.kernel.org/stable/c/440447699c681e26ed58e9c309cad718270a18b4"},{"url":"https://git.kernel.org/stable/c/9fe74e42914c851d68069713b7b917a9c33faf26"},{"url":"https://git.kernel.org/stable/c/99e22ddf4edb63dc8382bc028af928056d3450cf"}],"tags":["cve.org"],"epss":0.00135,"epssPercentile":0.02628,"ingestedAt":"2026-10-16T17:24:46.805Z","slug":"CVE-2026-64115","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nvsock/vmci: fix UAF when peer resets connection during handshake\n\nvmci_transport_recv_connecting_server() returned err = 0 for a peer\nRST in its default switch arm:\n\n\terr = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;\n\nThat made vmci_transport_recv_listen() skip vsock_remove_pending(),\nleaving the pending socket on the listener's pending_links with\nsk_state = TCP_CLOSE while destroy: still dropped the explicit\nreference taken before schedule_delayed_work().\n\nOne second later vsock_pending_work() observed is_pending=true and\nperformed full cleanup: vsock_remove_pending() then the two trailing\nsock_put(sk) calls -- the first reached refcount 0 and __sk_freed\nthe socket, and the second wrote into the freed object:\n\n  BUG: KASAN: slab-use-after-free in refcount_warn_saturate\n  Write of size 4 at addr ffff88800b1cac80 by task kworker\n  Workqueue: events vsock_pending_work\n\nTreat peer RST like any other unexpected packet type (err = -EINVAL).\nAll destroy: arms now return err < 0, so vmci_transport_recv_listen()\nremoves pending from pending_links synchronously and\nvsock_pending_work() takes the is_pending=false / !rejected branch,\ndropping only its own work reference.  This also closes the\nmulti-packet race Sashiko reported on v2: pending is removed from\nthe list before any subsequent packet can find it.\n\nThe pre-existing sk_acceptq_removed() gap on the err < 0 path of\nvmci_transport_recv_listen() that Sashiko also noted is not\nintroduced or changed by this patch.\n\nTested on lts-6.12.79 with KASAN: 52/100 unpatched -> 0/100 patched.\n\n## Affected\n\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 1e19f08552b90070ed18bafb1763c78297823af6`\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 1dd531e28f61edd286edc486ab068f135b5ae1eb`\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < ecda37f8faab3220da199335e42564cb7a9ad145`\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb`\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9`\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 440447699c681e26ed58e9c309cad718270a18b4`\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 9fe74e42914c851d68069713b7b917a9c33faf26`\n- `Linux >= d021c344051af91f42c5ba9fdedc176740cbd238 < 99e22ddf4edb63dc8382bc028af928056d3450cf`\n- `Linux 3.9`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":48.4,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}