CVE-2026-63923CWE-787

CVE-2026-63923

High · published July 19, 2026

CVSS v3.1
8.8
EPSS
0%
Percentile
5.5
In the wild
Unconfirmed
What it is

In 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.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00166 · 5.5th percentile
Weakness
CWE-787 · Out-of-bounds Write
Published
2026-07-19T20:17Z
References (3)
EPSS history
Timeline
  • 19 JUL 14:55Z
    octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify
    cvelistv5