GHSA-95J3-7Q26-W637
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-08-03 12:32In the Linux kernel, the following vulnerability has been resolved:
octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify
rvu_mbox_handler_rep_event_notify() in drivers/net/ethernet/marvell/ octeontx2/af/rvu_rep.c queues a sender-controlled REP_EVENT_NOTIFY request body verbatim, and rvu_rep_up_notify() then forwards event->pcifunc (the nested body field, distinct from the AF-normalised header pcifunc) into rvu_get_pfvf(), rvu_get_pf() and the AF->PF mailbox device index without any bounds check.
A VF attached to a PF that has been put into switchdev representor mode reaches this path: the VF mailbox handler otx2_pfvf_mbox_handler() forwards every message id including MBOX_MSG_REP_EVENT_NOTIFY to AF without an allowlist, and the AF dispatcher rewrites only msg->pcifunc, leaving struct rep_event::pcifunc attacker-controlled. The sibling rvu_mbox_handler_esw_cfg() refuses requests whose header pcifunc is not rvu->rep_pcifunc; this handler has no equivalent gate.
An out-of-range body pcifunc selects an &rvu->pf[]/&rvu->hwvf[] element past the allocated array and, for RVU_EVENT_MAC_ADDR_CHANGE, turns into a six-byte attacker-chosen OOB ether_addr_copy() target inside the queued worker; KASAN reports a slab-out-of-bounds write in rvu_rep_wq_handler.
Reject malformed requests at the handler entry by gating on is_pf_func_valid(), which is already the canonical PF/VF range check in this driver; expose it via rvu.h so callers in rvu_rep.c can use it instead of open-coding the same range arithmetic.
{
"affected": [],
"aliases": [
"CVE-2026-63923"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:10Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocteontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify\n\nrvu_mbox_handler_rep_event_notify() in drivers/net/ethernet/marvell/\nocteontx2/af/rvu_rep.c queues a sender-controlled REP_EVENT_NOTIFY\nrequest body verbatim, and rvu_rep_up_notify() then forwards\nevent-\u003epcifunc (the nested body field, distinct from the\nAF-normalised header pcifunc) into rvu_get_pfvf(), rvu_get_pf() and\nthe AF-\u003ePF mailbox device index without any bounds check.\n\nA VF attached to a PF that has been put into switchdev\nrepresentor mode reaches this path: the VF mailbox handler\notx2_pfvf_mbox_handler() forwards every message id including\nMBOX_MSG_REP_EVENT_NOTIFY to AF without an allowlist, and the AF\ndispatcher rewrites only msg-\u003epcifunc, leaving struct\nrep_event::pcifunc attacker-controlled. The sibling\nrvu_mbox_handler_esw_cfg() refuses requests whose header pcifunc\nis not rvu-\u003erep_pcifunc; this handler has no equivalent gate.\n\nAn out-of-range body pcifunc selects an \u0026rvu-\u003epf[]/\u0026rvu-\u003ehwvf[]\nelement past the allocated array and, for RVU_EVENT_MAC_ADDR_CHANGE,\nturns into a six-byte attacker-chosen OOB ether_addr_copy() target\ninside the queued worker; KASAN reports a slab-out-of-bounds write\nin rvu_rep_wq_handler.\n\nReject malformed requests at the handler entry by gating on\nis_pf_func_valid(), which is already the canonical PF/VF range check\nin this driver; expose it via rvu.h so callers in rvu_rep.c can use\nit instead of open-coding the same range arithmetic.",
"id": "GHSA-95j3-7q26-w637",
"modified": "2026-08-03T12:32:36Z",
"published": "2026-07-19T18:31:46Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63923"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2156a29aecfffa2eb7c558255690084efbe9f3b0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4467fa514482bbce82f73788943c815f3d126ab3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/68be0260e2a02ff9b18a8678d5f8d1715fa20138"
}
],
"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"
}
]
}
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