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CVE-2026-72410
octeontx2-af: Validate NIX maximum LFs correctly
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/net. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-72410 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 | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| 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
NIX maximum number of LFs can be set via devlink command but that can be done before assigning any LFs to a PF/VF. The condition used to check whether any LFs are assigned is incorrect. This patch fixes that condition.
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_devlink.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
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.18%, higher than 6.5% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- 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 |
|---|---|---|
| 6.8 | 6.12.97 | 0933fe0130eb |
| 6.8 | 6.18.40 | e0ac054416bf |
| 6.8 | 7.1.5 | b1f6381acf9d |
| 6.8 | 7.2 | 1576d12a3986 |
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
- The flaw is reached only via DEVLINK_CMD_PARAM_SET netlink to the octeontx2-af RVU Admin Function devlink "nix_maxlf" parameter; there is no remote packet, mbox, or ioctl path into rvu_af_dl_nix_maxlf_validate()/set().
- AC:LAttack complexity, low
- A CAP_NET_ADMIN caller can deterministically attach NIX LFs (PF/VF netdev probe) and issue the devlink set in the window before MCAM entries are allocated; the buggy mcam->bmap_fcnt check is bypassed whenever LFs are assigned but the MCAM bitmap is still full.
- PR:LPrivileges required, low
- DEVLINK_CMD_PARAM_SET requires GENL_ADMIN_PERM (CAP_NET_ADMIN). On OcteonTX2 cloud/edge servers the AF devlink is host-local admin surface reachable by any principal holding netdev admin capability, including container runtimes granted CAP_NET_ADMIN.
- UI:NUser interaction, none
- Exploitation is fully programmatic via devlink netlink and concurrent netdev bringup; no victim click, mount, or other interactive action is required beyond the attacker's own administrative commands.
- S:UScope, unchanged
- Impact is confined to kernel/AF driver state on the host managing the Marvell OcteonTX2 NIC; it does not cross a VM-hypervisor, IOMMU, or container sandbox boundary to compromise a separate security authority.
- C:HConfidentiality impact, high
- Bypassing validation lets rvu_af_dl_nix_maxlf_set() change block->lf.max while LFs remain assigned, tear down MCAM tracking via npc_mcam_rsrcs_deinit(), and reinit with wrong nixlf_count, desynchronizing MCAM index math and enabling out-of-bounds reads of kmalloc'd MCAM metadata.
- I:HIntegrity impact, high
- The same desync corrupts MCAM entry2pfvf_map/entry2cntr_map bookkeeping and NIX LF resource maps while hardware LFs stay attached, giving attacker-influenced out-of-bounds writes during subsequent MCAM/NIX operations and a plausible path to kernel code execution.
- A:HAvailability impact, high
- Forcing MCAM reinitialization and inconsistent LF limits on an active OcteonTX2 AF can panic/oops the kernel or wedge NIC packet processing on internet-facing servers and telco/cloud nodes that depend on this hardware for line-rate networking.