iio: health: max30102: fix NULL dereference in interrupt handler

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The interrupt is requested in max30102_probe() and stays enabled
for the lifetime of the device, but indio_dev->active_scan_mask is only
valid while a buffer is enabled. When an interrupt arrives while no
buffer is enabled, the handler dereferences the NULL active_scan_mask:

  Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
  Call trace:
   __bitmap_weight+0x64/0x98 (P)
   max30102_interrupt_handler+0x48/0x160 [max30102]

Call max30102_fifo_count() at the top of the handler and return early
unless it reports a FIFO sample is ready. Because FIFO_RDY is the only
interrupt source enabled in max30102_chip_init(), an invocation of
max30102_interrupt_handler() without the FIFO_RDY interrupt status bit
set carries no data to read and can return before touching
active_scan_mask. A negative return from max30102_fifo_count()
indicates a failed interrupt status read and is treated the same way.

Fixes: 90579b69e9 ("iio: health: max30102: Add MAX30105 support")
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Marco Chen <marcochen.dev@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

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Marco Chen 2026-08-08 15:54:50 -04:00 • committed by Jonathan Cameron

parent cee9395acd

commit f0ea4824de

1 changed files with 9 additions and 3 deletions

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drivers/iio/health/max30102.c

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