{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-64115", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-64115" ], "published": "2026-07-19T15:41:06Z", "summary": "vsock/vmci: fix UAF when peer resets connection during handshake", "details": "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\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.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.175", "compiled_filter": false } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-64115" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/1e19f08552b90070ed18bafb1763c78297823af6" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/1dd531e28f61edd286edc486ab068f135b5ae1eb" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/ecda37f8faab3220da199335e42564cb7a9ad145" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/440447699c681e26ed58e9c309cad718270a18b4" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/9fe74e42914c851d68069713b7b917a9c33faf26" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/99e22ddf4edb63dc8382bc028af928056d3450cf" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-05T13:16:28Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 8.8, "cvss_v3_severity": "High", "scenario": "AV:L - Exploitation requires local AF_VSOCK syscalls (connect/close) to drive VMCI control packets; per kernel CVSS guidance, vsock is scored Local even when the peer is a VM guest reaching a host listener.\nAC:L - The attacker controls both sides of the handshake race by initiating a connection and aborting it with RST during TCP_SYN_SENT; KASAN testing showed 52/100 repro without conditions outside attacker control.\nPR:L - Any unprivileged local user inside a VM (or on the same host) can open AF_VSOCK sockets and connect to a listening peer without CAP_NET_ADMIN or other elevated privileges.\nUI:N - Exploitation requires only a victim service with a bound/listening vsock socket, which is normal background operation; no interactive victim action is needed.\nS:C - In the most severe reasonable VMware deployment, an unprivileged guest VM triggers kernel memory corruption on the hypervisor host via VMCI vsock, crossing the guest-to-host virtualisation security boundary analogous to KVM/Xen VM escape.\nC:H - The bug is a slab use-after-free on struct sock; UAF on kernel heap objects enables arbitrary memory read primitives through controlled reuse of the freed socket structure.\nI:H - The UAF involves a write to a freed object's refcount field and corrupts kernel heap metadata, providing a foundation for arbitrary write and kernel code execution via heap grooming.\nA:H - The vulnerability reliably triggers kernel UAF detected by KASAN (refcount write to freed memory on a kworker), which causes kernel oops/panic and denial of host availability." } } }