High severity · published Jul 19, 2026
CVE-2026-63923
octeontx2-af: validate body pcifunc in rvu_mbox_handler_rep_event_notify
8.8
CVSS
0.2%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
6.13 before 6.18.42; 6.19 before 7.0.12; 7.1; 7.1; 7.1; 7.1; +1 more · source: NVD
LI
Linux · Linux
b8fea84a0468404fe3b3327ad54d583950be9dec before 4467fa514482bbce82f73788943c815f3d126ab3; b8fea84a0468404fe3b3327ad54d583950be9dec before 68be0260e2a02ff9b18a8678d5f8d1715fa20138; b8fea84a0468404fe3b3327ad54d583950be9dec before 2156a29aecfffa2eb7c558255690084efbe9f3b0; 6.13 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63923
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-63923
Patch
https://git.kernel.org/stable/c/2156a29aecfffa2eb7c558255690084efbe9f3b0
Patch
https://git.kernel.org/stable/c/4467fa514482bbce82f73788943c815f3d126ab3
Patch
https://git.kernel.org/stable/c/68be0260e2a02ff9b18a8678d5f8d1715fa20138
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