CVE-2026-63923

In the Linux kernel, the following vulnerability has been resolved:

octeontx2-af: validate body pcifunc in rvumboxhandlerrepevent_notify

rvumboxhandlerrepeventnotify() in drivers/net/ethernet/marvell/ octeontx2/af/rvurep.c queues a sender-controlled REPEVENTNOTIFY request body verbatim, and rvurepupnotify() then forwards event->pcifunc (the nested body field, distinct from the AF-normalised header pcifunc) into rvugetpfvf(), rvuget_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 otx2pfvfmboxhandler() forwards every message id including MBOXMSGREPEVENTNOTIFY to AF without an allowlist, and the AF dispatcher rewrites only msg->pcifunc, leaving struct repevent::pcifunc attacker-controlled. The sibling rvumboxhandlereswcfg() 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 RVUEVENTMACADDRCHANGE, turns into a six-byte attacker-chosen OOB etheraddrcopy() target inside the queued worker; KASAN reports a slab-out-of-bounds write in rvurepwq_handler.

Reject malformed requests at the handler entry by gating on ispffuncvalid(), which is already the canonical PF/VF range check in this driver; expose it via rvu.h so callers in rvurep.c can use it instead of open-coding the same range arithmetic.