media: mali-c55: Fix scaler factor overflow for large crop sizes

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The horizontal and vertical scaling factors multiply the crop dimensions
by MALI_C55_RSZ_SCALER_FACTOR, a Q4.20 factor of (1 << 20). Both operands
are 32-bit, so the multiplication wraps before the result is stored in
the u64 scale variables. For any crop dimension of 4096 or more (the
maximum is 8192) the value overflows; an 8192 to 4096 downscale yields a
TINC of zero, so the scaler never advances and the output is corrupted.

Define MALI_C55_RSZ_SCALER_FACTOR as a 64-bit constant so the
multiplication is performed in 64-bit.

Fixes: d5f281f3dd ("media: mali-c55: Add Mali-C55 ISP driver")
Cc: stable@vger.kernel.org
Signed-off-by: David Carlier <devnexen@gmail.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

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David Carlier 2026-06-18 20:52:54 +01:00 • committed by Hans Verkuil

parent 9a2925b823

commit 2447c768cb

1 changed files with 1 additions and 1 deletions

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drivers/media/platform/arm/mali-c55/mali-c55-resizer.c

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