From d17a51bc59462b136635515e40019c8ae4e05b5e Mon Sep 17 00:00:00 2001 From: Ameer J <52414509+ameerj@users.noreply.github.com> Date: Sun, 30 Jul 2023 13:05:45 -0400 Subject: [PATCH] extractbits robustness --- src/video_core/host_shaders/astc_decoder.comp | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/src/video_core/host_shaders/astc_decoder.comp b/src/video_core/host_shaders/astc_decoder.comp index 4277b07569..f65e1d1b9c 100644 --- a/src/video_core/host_shaders/astc_decoder.comp +++ b/src/video_core/host_shaders/astc_decoder.comp @@ -349,14 +349,17 @@ uint ExtractBits(uvec4 payload, int offset, int bits) { if (bits <= 0) { return 0; } - int last_offset = offset + bits - 1; - int shifted_offset = offset >> 5; + if (bits > 32) { + return 0; + } + const int last_offset = offset + bits - 1; + const int shifted_offset = offset >> 5; if ((last_offset >> 5) == shifted_offset) { return bitfieldExtract(payload[shifted_offset], offset & 31, bits); } - int first_bits = 32 - (offset & 31); - int result_first = int(bitfieldExtract(payload[shifted_offset], offset & 31, first_bits)); - int result_second = int(bitfieldExtract(payload[shifted_offset + 1], 0, bits - first_bits)); + const int first_bits = 32 - (offset & 31); + const int result_first = int(bitfieldExtract(payload[shifted_offset], offset & 31, first_bits)); + const int result_second = int(bitfieldExtract(payload[shifted_offset + 1], 0, bits - first_bits)); return result_first | (result_second << first_bits); }