GHSA-C2C8-F8X2-CHFH
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:32In the Linux kernel, the following vulnerability has been resolved:
vsock/vmci: fix UAF when peer resets connection during handshake
vmci_transport_recv_connecting_server() returned err = 0 for a peer RST in its default switch arm:
err = pkt->type == VMCI_TRANSPORT_PACKET_TYPE_RST ? 0 : -EINVAL;
That made vmci_transport_recv_listen() skip vsock_remove_pending(), leaving the pending socket on the listener's pending_links with sk_state = TCP_CLOSE while destroy: still dropped the explicit reference taken before schedule_delayed_work().
One second later vsock_pending_work() observed is_pending=true and performed full cleanup: vsock_remove_pending() then the two trailing sock_put(sk) calls -- the first reached refcount 0 and __sk_freed the socket, and the second wrote into the freed object:
BUG: KASAN: slab-use-after-free in refcount_warn_saturate Write of size 4 at addr ffff88800b1cac80 by task kworker Workqueue: events vsock_pending_work
Treat peer RST like any other unexpected packet type (err = -EINVAL). All destroy: arms now return err < 0, so vmci_transport_recv_listen() removes pending from pending_links synchronously and vsock_pending_work() takes the is_pending=false / !rejected branch, dropping only its own work reference. This also closes the multi-packet race Sashiko reported on v2: pending is removed from the list before any subsequent packet can find it.
The pre-existing sk_acceptq_removed() gap on the err < 0 path of vmci_transport_recv_listen() that Sashiko also noted is not introduced or changed by this patch.
Tested on lts-6.12.79 with KASAN: 52/100 unpatched -> 0/100 patched.
{
"affected": [],
"aliases": [
"CVE-2026-64115"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:52Z",
"severity": "HIGH"
},
"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-\u003etype == 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\u0027s 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 \u003c 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 \u003c 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 -\u003e 0/100 patched.",
"id": "GHSA-c2c8-f8x2-chfh",
"modified": "2026-07-20T15:32:00Z",
"published": "2026-07-19T18:31:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64115"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1dd531e28f61edd286edc486ab068f135b5ae1eb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1e19f08552b90070ed18bafb1763c78297823af6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/440447699c681e26ed58e9c309cad718270a18b4"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/47e63077605c6c2aa45b3df9847a8cdc1f1f6ef9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/99e22ddf4edb63dc8382bc028af928056d3450cf"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9fe74e42914c851d68069713b7b917a9c33faf26"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cc27e989a5dfdfcfc1cca7c3be27a0c7532b46cb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ecda37f8faab3220da199335e42564cb7a9ad145"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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