iio: accel: bmc150: clamp the device-reported FIFO frame count

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__bmc150_accel_fifo_flush() transfers the frame count the device reports
in FIFO_STATUS into an on-stack buffer sized for BMC150_ACCEL_FIFO_LENGTH
(32) samples, but the count is masked to 7 bits (0..127) and the optional
caller budget does not bound the flush-all path. A device, or an attacker
on the I2C/SPI bus, reporting up to 127 frames overflows the buffer by up
to 570 bytes: a stack out-of-bounds write.

Clamp the count to BMC150_ACCEL_FIFO_LENGTH before the transfer, mirroring
the clamp already applied in bmc150_accel_set_watermark(). Conforming
hardware reports at most that many frames and is unaffected.

Signed-off-by: Bryam Vargas <hexlabsecurity@proton.me>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

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Bryam Vargas 2026-06-16 20:56:51 -05:00 • committed by Jonathan Cameron

parent e8de771d80

commit d2a4411137

1 changed files with 4 additions and 2 deletions

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drivers/iio/accel/bmc150-accel-core.c

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