{"id":"CVE-2026-64115","state":"PUBLISHED","title":"vsock/vmci: fix UAF when peer resets connection during handshake","description":"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.","publishedAt":"2026-07-19T15:40:15.513Z","updatedAt":"2026-10-19T20:28:12.821Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"1e19f08552b90070ed18bafb1763c78297823af6","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"1dd531e28f61edd286edc486ab068f135b5ae1eb","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"ecda37f8faab3220da199335e42564cb7a9ad145","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"440447699c681e26ed58e9c309cad718270a18b4","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"9fe74e42914c851d68069713b7b917a9c33faf26","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"99e22ddf4edb63dc8382bc028af928056d3450cf","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/vmci_transport.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.9","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/vmci_transport.c"]}],"references":["https://git.kernel.org/stable/c/1e19f08552b90070ed18bafb1763c78297823af6","https://git.kernel.org/stable/c/1dd531e28f61edd286edc486ab068f135b5ae1eb","https://git.kernel.org/stable/c/ecda37f8faab3220da199335e42564cb7a9ad145","https://git.kernel.org/stable/c/cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb","https://git.kernel.org/stable/c/47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9","https://git.kernel.org/stable/c/440447699c681e26ed58e9c309cad718270a18b4","https://git.kernel.org/stable/c/9fe74e42914c851d68069713b7b917a9c33faf26","https://git.kernel.org/stable/c/99e22ddf4edb63dc8382bc028af928056d3450cf"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64115.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64115","state":"PUBLISHED","datePublished":"2026-07-19T15:40:15.513Z","dateUpdated":"2026-10-19T20:28:12.821Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.035Z"},"containers":{"cna":{"title":"vsock/vmci: fix UAF when peer resets connection during handshake","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"1e19f08552b90070ed18bafb1763c78297823af6","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"1dd531e28f61edd286edc486ab068f135b5ae1eb","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"ecda37f8faab3220da199335e42564cb7a9ad145","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"440447699c681e26ed58e9c309cad718270a18b4","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"9fe74e42914c851d68069713b7b917a9c33faf26","versionType":"git"},{"version":"d021c344051af91f42c5ba9fdedc176740cbd238","status":"affected","lessThan":"99e22ddf4edb63dc8382bc028af928056d3450cf","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/vmci_transport.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.9","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/vmw_vsock/vmci_transport.c"]}],"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"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","baseScore":8.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:39:24.360Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.9","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64115","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:36:34.520586Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:28:12.821Z"}}]}}}