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Maxwell Doose
820c4f1535
commite561b35633upstream. In the report from Jaeyoung Chung: "lpc32xx_adc_probe() in drivers/iio/adc/lpc32xx_adc.c registers its interrupt handler with devm_request_irq() before it initializes st->completion with init_completion(). If an interrupt arrives after devm_request_irq() and before init_completion(), the handler calls complete() on an uninitialized completion, causing a kernel panic. The probe path, in lpc32xx_adc_probe(): iodev = devm_iio_device_alloc(&pdev->dev, sizeof(*st)); /* st kzalloc-zeroed */ ... retval = devm_request_irq(&pdev->dev, irq, lpc32xx_adc_isr, 0, LPC32XXAD_NAME, st); /* register handler */ ... init_completion(&st->completion); /* initialize completion */ lpc32xx_adc_isr() calls complete(): complete(&st->completion); If the device raises an interrupt before init_completion() runs, complete() acquires the uninitialized wait.lock and walks the zeroed task_list in swake_up_locked(). The zeroed task_list makes list_empty() return false, so swake_up_locked() dereferences a NULL list entry, triggering a KASAN wild-memory-access." Fix the chance of a spurious IRQ causing an uninitialized pointer dereference by moving init_completion() above devm_request_irq(). Fixes:7901b2a145("staging:iio:adc:lpc32xx rename local state structure to _state") Reported-by: Sangyun Kim <sangyun.kim@snu.ac.kr> Reported-by: Kyungwook Boo <bookyungwook@gmail.com> Reported-by: Jaeyoung Chung <jjy600901@snu.ac.kr> Closes: https://lore.kernel.org/linux-iio/20260610115700.774689-1-jjy600901@snu.ac.kr/ Signed-off-by: Maxwell Doose <m32285159@gmail.com> Reviewed-by: Vladimir Zapolskiy <vz@kernel.org> Cc: <Stable@vger.kernel.org> Signed-off-by: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.