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CVE-2026-72045
octeontx2-af: cn10k: restrict VF LMTLINE sharing to its own PF
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-2026-72045 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 | fixedDLA-4777-1 · 2026-09-08 · text | 6.1.187-1 | Update the kernel and reboot. DLA-4777-1 shipped the fix on 2026-09-08, in 6.1.187-1. A running kernel keeps the old code until the machine restarts. |
| Debian 13trixie | fixed | 6.12.101-1 | Update the kernel and reboot. Fixed in 6.12.101-1. 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. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4745-1 · 2026-08-18 · text | 6.12.101-1~deb12u1 | Update the kernel and reboot. DLA-4745-1 shipped the fix on 2026-08-18, in 6.12.101-1~deb12u1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
rvu_mbox_handler_lmtst_tbl_setup() uses req->base_pcifunc as a direct index into the LMT map table to read another function's LMTLINE physical base address and copy it into the caller's own LMT map table entry. The mailbox dispatcher authenticates req->hdr.pcifunc from the IRQ source, but req->base_pcifunc is a separate payload field and is not sanitized. Reject the request with -EPERM when a VF caller's base_pcifunc is not a valid function under its own PF. is_pf_func_valid() bounds the FUNC field to the PF's configured VF count, keeping the computed index inside the caller's own slot block.
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_cn10k.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 4 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
- bookworm · linux-6.12Mnot built on amd64/amd64, amd64/cloud-amd64, amd64/rt/amd64, arm64/cloud-arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
- 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
- 8.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.17%, higher than 5.8% 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 | 5.15.217 | 04c014e49b9f |
| 5.14 | 6.1.184 | 6967dd944be2 |
| 5.14 | 6.6.148 | e9c5b0320850 |
| 5.14 | 6.12.101 | 54535692bec9 |
| 5.14 | 6.18.42 | c73b8795b45f |
| 5.14 | 7.1.5 | 59da37fee81a |
| 5.14 | 7.2 | 8cdcf3d2caac |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4777-1 | 2026-09-08 | bookworm 6.1.187-1 | tracker |
| DLA-4745-1 | 2026-08-18 | bookworm 6.12.101-1~deb12u1 | tracker |
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 assigned Marvell CN10K/OCTEONTX2 SR-IOV VF and sending a crafted LMTST_TBL_SETUP mailbox message over the PCI VF→AF control path (rvu_afvf_mbox_handler→rvu_mbox_handler_lmtst_tbl_setup); it is not reachable via remote packet delivery.
- AC:LAttack complexity, low
- Once a VF is assigned, the attacker fully controls the unsanitized base_pcifunc payload field and can trigger the flaw deterministically with a single mailbox message; no race, special memory layout, or victim timing is required.
- PR:LPrivileges required, low
- Only control of an assigned VF is needed (typical cloud/tenant VM or container with SR-IOV passthrough, or guest root/CAP_NET_ADMIN managing the VF); host init-namespace root is not required and unprivileged host users cannot reach this hardware mailbox without the VF device.
- UI:NUser interaction, none
- No victim user action is required; the attacker directly sends the malicious LMTST_TBL_SETUP mailbox request from their VF to the AF handler.
- S:CScope, changed
- A malicious VF tenant can retarget hardware LMTLINE stores to another PF/VF's memory region, crossing the SR-IOV tenant isolation boundary and enabling guest-to-host or guest-to-guest impact on shared CN10K NIC deployments.
- C:HConfidentiality impact, high
- Redirecting a VF's LMT map entry to another function's LMTLINE region lets the attacker read victim in-flight packet/crypto submission metadata and buffer pointers from shared hardware LMT memory, constituting cross-tenant information disclosure beyond the attacker's scope.
- I:HIntegrity impact, high
- After the map-table redirect, the attacker's LMTST flush operations (packet TX SQE submission, NPA aura free, CPT enqueue) are hardware-written into the victim's LMTLINE physical pages, enabling arbitrary cross-tenant memory corruption and potential control of victim I/O submission state.
- A:HAvailability impact, high
- Corrupting another PF/VF's LMTLINE submission buffers can crash or hang the victim's networking/crypto stack (guest kernel oops/panic or persistent TX failure) and the attack can be repeated on demand by resending mailbox requests.