gpio: cdev: fix kernel stack leak to user-space in error path

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If we fail to acquire the GPIO chip guard in gpio_desc_to_lineinfo(), we
return immediately before zeroing the info struct we'll end up passing
to the user-space later in lineinfo_get_v1(). This may leak the kernel
stack contents. Make gpio_desc_to_lineinfo() return int so that the
-ENODEV returned on failure to acquire the guard can be propagated to
the callers.

While not strictly necessary: move the memset() before trying to acquire
the SRCU read lock too for good measure.

Fixes: d83cee3d2b ("gpio: protect the pointer to gpio_chip in gpio_device with SRCU")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/20260912123529.7951-1-tzungbi%40kernel.org?part=3
Reviewed-by: Kent Gibson <warthog618@gmail.com>
Link: https://patch.msgid.link/20260922-gpio-cdev-stack-leak-fixes-v3-1-7a0c7a4299d5@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

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This commit is contained in:

Bartosz Golaszewski 2026-09-22 10:52:28 +02:00

parent 0b9828c723

commit 1feb5d39b0

1 changed files with 25 additions and 7 deletions

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drivers/gpio/gpiolib-cdev.c

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