CVE-2025-71299: spi: cadence-quadspi: Parse DT for flashes with the rest of the DT parsing

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

From: Greg Kroah-Hartman <gregkh@kernel.org>

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

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

spi: cadence-quadspi: Parse DT for flashes with the rest of the DT parsing

The recent refactoring of where runtime PM is enabled done in commit
f1eb4e792bb1 ("spi: spi-cadence-quadspi: Enable pm runtime earlier to
avoid imbalance") made the fact that when we do a pm_runtime_disable()
in the error paths of probe() we can trigger a runtime disable which in
turn results in duplicate clock disables.  This is particularly likely
to happen when there is missing or broken DT description for the flashes
attached to the controller.

Early on in the probe function we do a pm_runtime_get_noresume() since
the probe function leaves the device in a powered up state but in the
error path we can't assume that PM is enabled so we also manually
disable everything, including clocks. This means that when runtime PM is
active both it and the probe function release the same reference to the
main clock for the IP, triggering warnings from the clock subsystem:

[    8.693719] clk:75:7 already disabled
[    8.693791] WARNING: CPU: 1 PID: 185 at /usr/src/kernel/drivers/clk/clk.c:1188 clk_core_disable+0xa0/0xb
...
[    8.694261]  clk_core_disable+0xa0/0xb4 (P)
[    8.694272]  clk_disable+0x38/0x60
[    8.694283]  cqspi_probe+0x7c8/0xc5c [spi_cadence_quadspi]
[    8.694309]  platform_probe+0x5c/0xa4

Dealing with this issue properly is complicated by the fact that we
don't know if runtime PM is active so can't tell if it will disable the
clocks or not.  We can, however, sidestep the issue for the flash
descriptions by moving their parsing to when we parse the controller
properties which also save us doing a bunch of setup which can never be
used so let's do that.

The Linux kernel CVE team has assigned CVE-2025-71299 to this issue.


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

	Fixed in 6.18.16 with commit 08dca4c8099a41a9fa3be128a793387603f73a17
	Fixed in 6.19.6 with commit dcaa104ad9c860a6dbd5797919e0ec0b1cd5a57a
	Fixed in 7.0 with commit 9f0736a4e136a6eb61e0cf530ddc18ab6d816ba3

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-2025-71299
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/spi/spi-cadence-quadspi.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/08dca4c8099a41a9fa3be128a793387603f73a17
	https://git.kernel.org/stable/c/dcaa104ad9c860a6dbd5797919e0ec0b1cd5a57a
	https://git.kernel.org/stable/c/9f0736a4e136a6eb61e0cf530ddc18ab6d816ba3