CVE-2026-64101

What the bug is

The fwctl core allocates the device-specific RPC input buffer with fwctl_rpc.in_len and passes that buffer to the driver callback. pdsfc_fw_rpc() casts the buffer to struct fwctl_rpc_pds and then calls pdsfc_validate_rpc(), which reads fields from that structure before checking that the input buffer is large enough to contain it. A short in_len can make pds_fwctl read beyond the allocation. Reject pds RPC buffers that are smaller than struct fwctl_rpc_pds before parsing any pds-specific fields.

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/fwctl/pds/main.c

What this is

FWCTL PDS DRIVERMAINTAINERS section matched on drivers/fwctl/pds/ · linux-kernel@vger.kernel.org · Maintained

Check it on the machine

grep -wE 'CONFIG_FWCTL|CONFIG_FWCTL_PDS' /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.

Show whether Debian builds this, per release

Debian does not build this code in 2 releases. The build rule could not be established for 2 releases, so nothing is claimed about those.

• bookworm, trixie?
• forky, sidn

?

not established - no Makefile entry for the affected file

n

not enabled on any flavour - this release does not build the code

Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.

Build switches

CONFIG_FWCTL, CONFIG_FWCTL_PDS

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

2026-07-19 (3 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.16%, higher than 4.7% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/fwctl

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.15	6.18.34	9e3f18883a98
6.15	7.0.11	0d470d365510
6.15	7.1	e7537735028c