Harry Wentland 930ec42d00 drm/amd/display: Reject gpio_bitshift >= 32 in bios_parser_get_gpio_pin_info() ...

commit 49c3da6596 upstream.

[Why & How]
gpio_bitshift is a uint8_t read directly from the VBIOS GPIO pin table.
If the value is >= 32, the expression "1 << gpio_bitshift" triggers
undefined behaviour in C (shift count exceeds type width). On x86 the
shift is silently masked to 5 bits, producing an incorrect GPIO mask
that may cause wrong MMIO register bits to be toggled.

Validate gpio_bitshift before use and return BP_RESULT_BADBIOSTABLE for
out-of-range values.

Fixes: ae79c310b1 ("drm/amd/display: Add DCE12 bios parser support")
Assisted-by: Copilot:claude-opus-4.6
Reviewed-by: Alex Hung <alex.hung@amd.com>
Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Ray Wu <ray.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit eadf438ab8)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

2026-06-19 13:21:38 +02:00

..

drm

drm/amd/display: Reject gpio_bitshift >= 32 in bios_parser_get_gpio_pin_info()

2026-06-19 13:21:38 +02:00

host1x

gpu: host1x: Do not setup DMA for virtual devices

2024-05-17 11:48:04 +02:00

ipu-v3

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trace

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vga

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Makefile

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