data built 2026-10-19T13:16:53Z

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CVE-2026-89596

forcedeth: fix off-by-one when saving/restoring non-PCI config space

7.1 EPSS 0.2% AV:L

Published 2026-09-11 (37 days 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-2026-89596 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

ReleaseStatus VersionWhat this means
Debian 12bookwormfixedDLA-4841-1 · 2026-10-17 · text6.1.190-1Update the kernel and reboot. DLA-4841-1 shipped the fix on 2026-10-17, in 6.1.190-1. A running kernel keeps the old code until the machine restarts.
Debian 13trixiefixedDSA-6528-1 · 2026-09-29 · text6.12.111-1Update the kernel and reboot. DSA-6528-1 shipped the fix on 2026-09-29, in 6.12.111-1. A running kernel keeps the old code until the machine restarts.
Debian 14forkyfixed7.2.6-1Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts.
Debian unstablesidfixed7.2.6-1Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts.
Debian 12bookworm · linux-6.12fixedDLA-4817-1 · 2026-10-04 · text6.12.111-1~deb12u1Update the kernel and reboot. DLA-4817-1 shipped the fix on 2026-10-04, in 6.12.111-1~deb12u1. A running kernel keeps the old code until the machine restarts.

The vulnerability

What the bug is

nv_suspend() and nv_resume() walk the non-PCI configuration space with for (i = 0; i <= np->register_size/sizeof(u32); i++) which runs one iteration too many. saved_config_space is declared as u32 saved_config_space[NV_PCI_REGSZ_MAX/4]; and NV_PCI_REGSZ_VER3 is equal to NV_PCI_REGSZ_MAX (0x604), so on a VER3 device register_size/sizeof(u32) is exactly the array length and the last iteration addresses one element past the end. The element it lands on is np->name_rx[0..3]: saved_config_space[] is followed immediately by char name_rx[IFNAMSIZ + 3], and char needs no padding. Nothing observable is corrupted by that, because nv_request_irq() rewrites name_rx with sprintf() before it is ever passed to request_irq(). The bug is the out-of-bounds access itself, which UBSAN reports and which CONFIG_UBSAN_TRAP=y turns into a trap that aborts the running kernel code, plus an MMIO read and, on resume, an MMIO writel() to base + 0x604, one dword past the range the driver mapped: np->base = ioremap(addr, np->register_size); VER1 and VER2 devices stay inside the array, but they too get the stray read and the stray write one dword past their own window. Caught by UBSAN on an Apple Macmini3,1 (MCP79) during a deep S3 cycle. The splat below is trimmed: the build path in the file name, the CPU and taint lines, the Workqueue line, the "?" hint frames, and the frames below device_suspend are all cut. The kernel was tainted, with an out-of-tree nouveau and CPU_OUT_OF_SPEC; forcedeth itself was the stock module. UBSAN: array-index-out-of-bounds in drivers/net/ethernet/nvidia/forcedeth.c:6225:25 index 385 is out of range for type 'u32 [385]' Call Trace: dump_stack_lvl+0x5d/0x80 ubsan_epilogue+0x5/0x2b __ubsan_handle_out_of_bounds.cold+0x54/0x59 __this_module+0xe398c/0xe9010 [forcedeth] pci_pm_suspend+0x80/0x170 dpm_run_callback+0x51/0x160 device_suspend+0x1a2/0x4a0 ... Both loops are hit. UBSAN reports each source location only once per module load (__ubsan_handle_out_of_bounds() calls suppress_report(), which does test_and_set_bit(REPORTED_BIT, ...) on the struct source_location), so the two splats land in the first S3 cycle after the module is loaded and later cycles are silent even though the access still runs off the end every time. In that first cycle line 6225 is reported from pci_pm_suspend and line 6240 from pci_pm_resume. The same off-by-one was fixed in nv_get_regs() by commit ba9aa134287f ("forcedeth: fix buffer overflow") in 2012; these two loops were missed. The suspend and resume side was reported on LKML in September 2013 by Marc Weber, with the same analysis and the same one-character fix, but the patch was attached rather than sent inline and the thread ended there. Use < instead of <=, which saves and restores exactly register_size bytes.

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/nvidia/forcedeth.c

What this is
FORCEDETH GIGABIT ETHERNET DRIVERMAINTAINERS section matched on drivers/net/ethernet/nvidia/* · netdev@vger.kernel.org · Maintained
Kernel module
forcedeth

Check it on the machine

grep -wE 'CONFIG_ETHERNET|CONFIG_FORCEDETH|CONFIG_NET_VENDOR_NVIDIA' /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 forcedeth

Prints 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 builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

  • bookwormMnot built on amd64/cloud-amd64, arm64/arm64, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le
  • trixieMnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/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/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt-arm64, armhf/armmp, armhf/armmp-lpae, loong64/loong64, ppc64el/powerpc64le, ppc64el/powerpc64le-64k, riscv64/riscv64, s390x/s390x
  • bookworm · linux-6.12Mnot built on amd64/cloud-amd64, arm64/arm64, arm64/arm64-16k, arm64/cloud-arm64, arm64/rt/arm64, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, ppc64el/powerpc64le, ppc64el/powerpc64le-64k
M
a module where it is built at all; some flavours do not build it
Build switches
CONFIG_ETHERNET, CONFIG_FORCEDETH, CONFIG_NET_VENDOR_NVIDIA
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
2026-09-11 (37 days ago)source
CVSS
7.1 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:Hsource recompute it
Attack vector
local (AV:L)source
EPSS
0.18%, higher than 6.9% 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

IntroducedFixed inCommit
2.6.275.10.270effd589568b2
2.6.275.15.221702aa4a44c87
2.6.276.1.188fc71c6c3d3e3
2.6.276.6.157c4d595358246
2.6.276.12.1099379f8527ca6
2.6.276.18.500c3f4544ff38
2.6.277.2.4c4f196bfeedd
2.6.277.39393f1d656a7

Debian advisories

AdvisoryDateShipped toDebian
DLA-4841-12026-10-17bookworm 6.1.190-1tracker
DLA-4817-12026-10-04bookworm 6.12.111-1~deb12u1tracker
DSA-6528-12026-09-29trixie 6.12.111-1tracker

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 off-by-one is only in nv_suspend()/nv_resume(), wired by SIMPLE_DEV_PM_OPS to PCI system-sleep and hibernation callbacks (pci_pm_suspend/resume plus freeze/thaw/poweroff/restore). Packet RX/TX, ethtool, and runtime PM never reach these functions.
AC:LAttack complexity, low
On VER3 nForce hardware, register_size equals NV_PCI_REGSZ_MAX, so the i <= register_size/4 loop always indexes one u32 past saved_config_space[] and issues one extra MMIO access. Every suspend/resume hits the bug with no race or attacker-uncontrollable layout.
PR:LPrivileges required, low
A local seat user on the realistic forcedeth deployments (desktops, HTPCs, Mac mini/MCP79) can start suspend via logind/polkit or idle/lid autosleep without init-namespace root. The kernel /sys/power/state store has no capability check (mode 0644).
UI:NUser interaction, none
The attacker initiates suspend or hibernate themselves (systemctl suspend, writing /sys/power/state, or waiting for autosleep). No separate victim action such as mounting a filesystem or opening a file is required.
S:UScope, unchanged
The extra store lands in the next field of the same fe_priv (allocated with the netdev) and the extra MMIO dword stays in the NIC's own BAR page. This does not cross a VM, sandbox, or IOMMU/DMA boundary.
C:NConfidentiality impact, none
The out-of-bounds slot is the adjacent name_rx[] IRQ-name buffer; nv_request_irq() sprintf()s it before request_irq(), and the extra MMIO dword is never copied to userspace. There is no kernel-memory disclosure primitive.
I:HIntegrity impact, high
This is a 4-byte out-of-bounds write past saved_config_space[] plus a matching writel() one dword past the ioremap() window on resume. Kernel CNA guidance scores out-of-bounds writes and stray MMIO restores as High integrity impact.
A:HAvailability impact, high
UBSAN reports array-index-out-of-bounds, and CONFIG_UBSAN_TRAP (Android GKI and other hardened kernels) turns that into a trap that aborts suspend/resume. An MMIO access past the mapped window can also hang or oops the host.