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CVE-2026-72312
octeontx2-af: fix VF bringup affecting PF promiscuous state
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-72312 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | fixed | 6.1.180-1 | Update the kernel and reboot. Fixed in 6.1.180-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.100-1 | Update the kernel and reboot. Fixed in 6.12.100-1. A running kernel keeps the old code until the machine restarts. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
Mbox handling of nix_set_rx_mode for a VF with promiscuous and all_multi flags set to false causes deletion of the PF's promiscuous and allmulti MCAM rules. This occurs because the APIs that enable/disable these rules operate only on the PF, even when the mbox request is made via a VF interface. Guard both rvu_npc_enable_allmulti_entry() and rvu_npc_enable_promisc_entry() disable paths with an is_vf() check so that a VF bringing up or tearing down its interface cannot inadvertently clear the PF's MCAM rules.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/net/ethernet/marvell/octeontx2/af/rvu_nix.c
- What this is
- MARVELL OCTEONTX2 RVU ADMIN FUNCTION DRIVERMAINTAINERS section matched on drivers/net/ethernet/marvell/octeontx2/af/ · netdev@vger.kernel.org · Maintained
- Kernel module
- rvu_af
Check it on the machine
grep -wE 'CONFIG_ETHERNET|CONFIG_NET_VENDOR_MARVELL|CONFIG_OCTEONTX2_AF|CONFIG_OCTEONTX2_MBOX' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w rvu_afPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian does not build this code in 1 release. It does build it in 3 releases, so the answer depends on which release the machine runs.
- bookwormn
- trixieMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- forky, sidMnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt-amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
- n
- not enabled on any flavour - this release does not build the code
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_ETHERNET, CONFIG_NET_VENDOR_MARVELL, CONFIG_OCTEONTX2_AF, CONFIG_OCTEONTX2_MBOX
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-15 (2 months ago)source
- CVSS
- 7.9 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.15%, higher than 4.1% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/net
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 5.14 | 6.1.178 | daa2451640a3 |
| 5.14 | 6.6.145 | 212c59e5e416 |
| 5.14 | 6.12.97 | 53e17d9ed779 |
| 5.14 | 6.18.40 | 3de77d2f34c2 |
| 5.14 | 7.1.5 | 3cf83432e056 |
| 5.14 | 7.2 | fabb881df322 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- Exploitation requires local control of an SR-IOV VF netdev on Marvell OcteonTX2/CN10K hardware; the bug is triggered via the VF driver's mailbox to the AF (rvu_mbox_handler_nix_set_rx_mode), not by remote packet delivery.
- AC:LAttack complexity, low
- An attacker with VF netdev access can reliably trigger the flaw by bringing the interface up/down or changing rx_mode (e.g., ip link set up), which sends NIX_SET_RX_MODE with promisc/allmulti cleared; no race or victim timing is required.
- PR:LPrivileges required, low
- Only guest/namespace CAP_NET_ADMIN (or equivalent root in an SR-IOV-assigned VM) is needed to manage the VF netdev; host init-namespace root is not required and user namespaces cannot reach this hardware path without the VF device.
- UI:NUser interaction, none
- No victim interaction is needed; the attacker initiates VF interface bringup/teardown or rx_mode updates that invoke otx2_do_set_rx_mode/otx2vf_do_set_rx_mode and the AF mbox handler.
- S:CScope, changed
- A VF tenant can alter PF-side NPC MCAM promiscuous/allmulti rules (rvu_npc_enable_promisc_entry/rvu_npc_enable_allmulti_entry mask pcifunc to the PF), crossing the SR-IOV isolation boundary between guest/tenant and host/provider packet filtering.
- C:LConfidentiality impact, low
- Disabling the PF promiscuous/allmulti MCAM entries can blind host IDS/tcpdump and other monitoring that depends on promiscuous reception, reducing visibility into network traffic on the affected PF (limited confidentiality impact, not arbitrary kernel memory read).
- I:LIntegrity impact, low
- The VF causes unauthorized modification of host-side hardware packet-filter state by disabling PF MCAM promisc/allmulti rules; this is limited integrity impact on network policy rather than arbitrary memory or code execution.
- A:HAvailability impact, high
- Clearing PF promiscuous and allmulti MCAM rules can break or degrade PF multicast delivery and promiscuous capture/monitoring on internet-facing cloud/edge servers using these NICs, and can be repeated by cycling the VF interface.