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CVE-2026-90341
firmware: coreboot: Validate table bounds
Published 2026-09-17 (31 days ago) by the Linux kernel CNA. Subsystem drivers/firmware. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-90341 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-4841-1 · 2026-10-17 · text | 6.1.190-1 | Update 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 13trixie | fixedDSA-6528-1 · 2026-09-29 · text | 6.12.111-1 | Update 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 14forky | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.6-1 | Update the kernel and reboot. Fixed in 7.2.6-1. A running kernel keeps the old code until the machine restarts. |
| Debian 12bookworm · linux-6.12 | fixedDLA-4817-1 · 2026-10-04 · text | 6.12.111-1~deb12u1 | Update 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
The existing coreboot_table_populate() bounds checks limit individual entries to the mapped length. However, coreboot_table_probe() replaces the platform resource length with header and table sizes supplied by firmware before mapping the full table. A malformed table can overflow the 32-bit size addition or advertise an extent beyond the resource, causing the driver to map and parse memory outside the resource. A resource shorter than the fixed header is also mapped as though it contained a complete header. Reject resources shorter than the fixed header. After validating the signature, require a complete header, calculate the advertised extent with overflow checking, and reject extents beyond the resource before remapping the table.
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/firmware/google/coreboot_table.c
- What this is
- GOOGLE FIRMWARE DRIVERSMAINTAINERS section matched on drivers/firmware/google/ · chrome-platform@lists.linux.dev · Maintained
- Kernel module
- coreboot_table
Check it on the machine
grep -wE 'CONFIG_GOOGLE_COREBOOT_TABLE|CONFIG_GOOGLE_FIRMWARE' /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 coreboot_tablePrints 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.
- bookwormb
- trixie, forky, sidBnot built on s390x/s390x
- bookworm · linux-6.12b
- b
- built in on some flavours, a module on others
- B
- built in on some, a module on others, absent on the rest
- Build switches
- CONFIG_GOOGLE_COREBOOT_TABLE, CONFIG_GOOGLE_FIRMWARE
- 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
- 2026-09-17 (31 days ago)source
- CVSS
- 7.7 high
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.19%, higher than 8.1% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- drivers/firmware
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 4.12 | 5.10.270 | 3cca0d6dd4c2 |
| 4.12 | 5.15.221 | f79f621215a0 |
| 4.12 | 6.1.188 | d848fac90c6f |
| 4.12 | 6.6.157 | 88027241c1d2 |
| 4.12 | 6.12.110 | fd93859ecfa5 |
| 4.12 | 6.18.52 | 2d98a3b89394 |
| 4.12 | 7.2.6 | e82f260a74de |
| 4.12 | 7.3 | a58a57a1076f |
Debian advisories
| Advisory | Date | Shipped to | Debian |
|---|---|---|---|
| DLA-4841-1 | 2026-10-17 | bookworm 6.1.190-1 | tracker |
| DLA-4817-1 | 2026-10-04 | bookworm 6.12.111-1~deb12u1 | tracker |
| DSA-6528-1 | 2026-09-29 | trixie 6.12.111-1 | 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
- The triggering fields are header->header_bytes and header->table_bytes in the LBIO table, read by coreboot_table_probe() after platform_get_resource(pdev, IORESOURCE_MEM, 0) from ACPI GOOGCB00/BOOT0000 _CRS or the OF /firmware/coreboot reg; those bytes come from firmware, not a network protocol message.
- AC:LAttack complexity, low
- coreboot_table_probe() replaces resource_size(res) with the u32 sum header_bytes+table_bytes before memremap() and coreboot_table_populate(); firmware that sets that sum past the ACPI/DT window, or a resource shorter than sizeof(*header), hits the over-map on every bind with no race.
- PR:NPrivileges required, none
- coreboot_table_probe() is the coreboot_table platform_driver probe from subsys_initcall, with no capable() or credential check; a malformed LBIO header at the GOOGCB00/coreboot MEM resource is parsed automatically, so no Linux account or user-namespace capability is required.
- UI:NUser interaction, none
- Binding the GOOGCB00/BOOT0000 or compatible="coreboot" platform device calls coreboot_table_probe() during boot or module load; the oversized memremap() happens on that probe with no mount, open, or other victim action.
- S:UScope, unchanged
- The oversized memremap() in coreboot_table_probe() and the memcpy() in coreboot_table_populate() stay in this kernel's coreboot table parser; this is not a KVM/Xen guest-to-host, IOMMU, or sandbox boundary crossing.
- C:HConfidentiality impact, high
- memremap(res->start, header_bytes+table_bytes) then coreboot_table_populate() memcpy's each entry->size from that mapping into a kmalloc'd coreboot_device; table_bytes is an unconstrained u32, so this is an unbounded over-read of physical memory past the ACPI/DT resource, not a few-byte leak.
- I:NIntegrity impact, none
- coreboot_table_populate() copies into kzalloc(sizeof(device->dev)+entry->size) using the same entry->size already checked against the (oversize) mapping, so the destination matches the copy; this path has no out-of-bounds write or control-flow hijack primitive.
- A:HAvailability impact, high
- try_ram_remap() in memremap() returns __va(res->start) after checking only the first pfn, so populate's walk of a table_bytes that extends past the reserved coreboot table/CBMEM window can fault on a linear-map hole or mixed RAM/MMIO range and oops or panic.