[ Upstream commit 18534df419 ]
gpiod_request_commit() copies the pointer to the label passed as
an argument only to be used later. But there's a chance the caller
could immediately free the passed string(e.g., local variable).
This could trigger a use after free when we use gpio label(e.g.,
gpiochip_unlock_as_irq(), gpiochip_is_requested()).
To be on the safe side: duplicate the string with kstrdup_const()
so that if an unaware user passes an address to a stack-allocated
buffer, we won't get the arbitrary label.
Also fix gpiod_set_consumer_name().
Signed-off-by: Muchun Song <smuchun@gmail.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
3555de57dc