diff --git a/src/gpu/graphite/dawn/DawnGraphiteUtils.cpp b/src/gpu/graphite/dawn/DawnGraphiteUtils.cpp
index 5bf6e7a769..1ec70908ee 100644
--- a/src/gpu/graphite/dawn/DawnGraphiteUtils.cpp
+++ b/src/gpu/graphite/dawn/DawnGraphiteUtils.cpp
@@ -312,19 +312,27 @@ ImmutableSamplerInfo DawnDescriptorToImmutableSamplerInfo(const wgpu::YCbCrVkDes
 
     const bool usesExternalFormat = DawnDescriptorUsesExternalFormat(desc);
 
+    // Mask each field to its allotted bit-width before shifting. The SkASSERTs
+    // above are debug-only; in release, hostile renderer-supplied values
+    // (e.g. vkYCbCrModel=0xFF via TransferableResource.ycbcr_info) would
+    // overflow into adjacent fields and produce an invalid wgpu::FilterMode
+    // on round-trip, reaching DAWN_UNREACHABLE in ToVulkanSamplerFilter.
+    #define SKGPU_PACK_FIELD(val, bits, shift) \
+        (((uint32_t)(val) & ((1u << (bits)) - 1u)) << (shift))
     ImmutableSamplerInfo info;
     info.fNonFormatYcbcrConversionInfo =
-            (((uint32_t)(usesExternalFormat               ) << kUsesExternalFormatShift) |
-             ((uint32_t)(desc.vkYCbCrModel                ) << kYcbcrModelShift        ) |
-             ((uint32_t)(desc.vkYCbCrRange                ) << kYcbcrRangeShift        ) |
-             ((uint32_t)(desc.vkXChromaOffset             ) << kXChromaOffsetShift     ) |
-             ((uint32_t)(desc.vkYChromaOffset             ) << kYChromaOffsetShift     ) |
-             ((uint32_t)(desc.vkChromaFilter              ) << kChromaFilterShift      ) |
-             ((uint32_t)(desc.forceExplicitReconstruction ) << kForceExplicitReconShift) |
-             ((uint32_t)(desc.vkComponentSwizzleRed       ) << kComponentRShift        ) |
-             ((uint32_t)(desc.vkComponentSwizzleGreen     ) << kComponentGShift        ) |
-             ((uint32_t)(desc.vkComponentSwizzleBlue      ) << kComponentBShift        ) |
-             ((uint32_t)(desc.vkComponentSwizzleAlpha     ) << kComponentAShift        ));
+            (SKGPU_PACK_FIELD(usesExternalFormat,                kUsesExternalFormatBits, kUsesExternalFormatShift) |
+             SKGPU_PACK_FIELD(desc.vkYCbCrModel,                 kYcbcrModelBits,         kYcbcrModelShift        ) |
+             SKGPU_PACK_FIELD(desc.vkYCbCrRange,                 kYcbcrRangeBits,         kYcbcrRangeShift        ) |
+             SKGPU_PACK_FIELD(desc.vkXChromaOffset,              kXChromaOffsetBits,      kXChromaOffsetShift     ) |
+             SKGPU_PACK_FIELD(desc.vkYChromaOffset,              kYChromaOffsetBits,      kYChromaOffsetShift     ) |
+             SKGPU_PACK_FIELD(desc.vkChromaFilter,               kChromaFilterBits,       kChromaFilterShift      ) |
+             SKGPU_PACK_FIELD(desc.forceExplicitReconstruction,  kForceExplicitReconBits, kForceExplicitReconShift) |
+             SKGPU_PACK_FIELD(desc.vkComponentSwizzleRed,        kComponentBits,          kComponentRShift        ) |
+             SKGPU_PACK_FIELD(desc.vkComponentSwizzleGreen,      kComponentBits,          kComponentGShift        ) |
+             SKGPU_PACK_FIELD(desc.vkComponentSwizzleBlue,       kComponentBits,          kComponentBShift        ) |
+             SKGPU_PACK_FIELD(desc.vkComponentSwizzleAlpha,      kComponentBits,          kComponentAShift        ));
+    #undef SKGPU_PACK_FIELD
     info.fFormat = usesExternalFormat ? desc.externalFormat : desc.vkFormat;
     return info;
 }