CVE-2026-72063: gpio: tegra: do not call pinctrl for GPIO direction

CVE-2026-72063: gpio: tegra: do not call pinctrl for GPIO direction

[Greg Kroah-Hartman]

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

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

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

gpio: tegra: do not call pinctrl for GPIO direction

tegra_gpio_direction_input() and tegra_gpio_direction_output() already
program the GPIO controller direction registers directly. The additional
pinctrl_gpio_direction_input/output() calls do not add a Tegra pinctrl
operation, because the Tegra pinmux ops provide GPIO request/free
handling but no gpio_set_direction hook.

The extra call still enters the pinctrl core and takes pctldev->mutex.
Shared GPIO users can call the direction path while holding their
per-line spinlock, so this otherwise redundant pinctrl direction call can
sleep in an atomic context.

This was found by our static analysis tool and then confirmed by manual
review of tegra_gpio_probe(), the Tegra GPIO direction callbacks and the
Tegra pinctrl ops. The reviewed path has a default non-sleeping
struct gpio_chip while the direction callback still enters the pinctrl
mutex path.

A directed runtime validation kept the same non-sleeping chip registration
and drove:

  gpio_shared_proxy_direction_output()
  gpiod_direction_output_raw_commit()
  tegra_gpio_direction_output()
  pinctrl_gpio_direction_output()

Lockdep reported a sleep-in-atomic warning with the shared GPIO spinlock
held and pinctrl_get_device_gpio_range() plus tegra_gpio_direction_output()
on the stack.

Do not mark the whole chip as can_sleep to paper over this: can_sleep
describes whether get()/set() may sleep, and Tegra value access is MMIO.
Remove the redundant pinctrl direction calls and keep pinctrl involvement
in the existing request/free path.

The Linux kernel CVE team has assigned CVE-2026-72063 to this issue.


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

	Issue introduced in 5.1 with commit 11da905412833d9b369a6a09a401f87149d674dc and fixed in 6.6.148 with commit e57a4845b0da60a7b9f052160878097826320954
	Issue introduced in 5.1 with commit 11da905412833d9b369a6a09a401f87149d674dc and fixed in 6.12.97 with commit cd17c5a1d9f186b57e9e2949be427803b7110a5c
	Issue introduced in 5.1 with commit 11da905412833d9b369a6a09a401f87149d674dc and fixed in 6.18.40 with commit ac761e66708d51dac35c4c7f1891ea991dc788f0
	Issue introduced in 5.1 with commit 11da905412833d9b369a6a09a401f87149d674dc and fixed in 7.1.5 with commit 628c63f96f4564fa145f602af2d41daf9532201f
	Issue introduced in 5.1 with commit 11da905412833d9b369a6a09a401f87149d674dc and fixed in 7.2-rc1 with commit d3e91a95b2b0fc6336dbf3ec90d831a1654d2720

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-2026-72063
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/gpio/gpio-tegra.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/e57a4845b0da60a7b9f052160878097826320954
	https://git.kernel.org/stable/c/cd17c5a1d9f186b57e9e2949be427803b7110a5c
	https://git.kernel.org/stable/c/ac761e66708d51dac35c4c7f1891ea991dc788f0
	https://git.kernel.org/stable/c/628c63f96f4564fa145f602af2d41daf9532201f
	https://git.kernel.org/stable/c/d3e91a95b2b0fc6336dbf3ec90d831a1654d2720