CVE-2026-64101: fwctl: pds: Validate RPC input size before parsing

From: Greg Kroah-Hartman <[email protected]>

Description
===========

In the Linux kernel, the following vulnerability has been resolved:

fwctl: pds: Validate RPC input size before parsing

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.

The Linux kernel CVE team has assigned CVE-2026-64101 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 6.15 with commit 92c66ee829b99a860a90f62ef16df3e42f92edac and fixed in 6.18.34 with commit 9e3f18883a98420a3b8873c6f894bc57e9b98e41
	Issue introduced in 6.15 with commit 92c66ee829b99a860a90f62ef16df3e42f92edac and fixed in 7.0.11 with commit 0d470d36551058e3f728574308b815a80bca710f
	Issue introduced in 6.15 with commit 92c66ee829b99a860a90f62ef16df3e42f92edac and fixed in 7.1 with commit e7537735028c3ad4b0bfc02ff8fa2a1a28aa04fe

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2026-64101
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/fwctl/pds/main.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/9e3f18883a98420a3b8873c6f894bc57e9b98e41
	https://git.kernel.org/stable/c/0d470d36551058e3f728574308b815a80bca710f
	https://git.kernel.org/stable/c/e7537735028c3ad4b0bfc02ff8fa2a1a28aa04fe