fix: resolve Miri UB in null struct field test, re-enable Miri on PRs#3669
Merged
andygrove merged 2 commits intoapache:mainfrom Mar 11, 2026
Merged
fix: resolve Miri UB in null struct field test, re-enable Miri on PRs#3669andygrove merged 2 commits intoapache:mainfrom
andygrove merged 2 commits intoapache:mainfrom
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Add bounds-checking debug_assert in SparkUnsafeRow::get_element_offset to catch out-of-bounds accesses early. Fix test_append_null_struct_field_to_struct_builder which had an undersized 8-byte buffer (only null bitset, no field slot) with null bit unset, causing an out-of-bounds read in get_long. Use 16 bytes with bit 0 set to properly represent a null field. Re-enable Miri on pull_request trigger now that the upstream cargo nightly regression (apache#3499) is resolved.
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Which issue does this PR close?
Closes #3499.
Rationale for this change
The Miri CI workflow on
mainis failing with undefined behavior intest_append_null_struct_field_to_struct_builder. Additionally, Miri was disabled on PR builds due to an upstream cargo nightly regression that has since been resolved.What changes are included in this PR?
debug_assertinSparkUnsafeRow::get_element_offsetto catch out-of-bounds element accesses earlytest_append_null_struct_field_to_struct_builder: the test buffer was only 8 bytes (just the null bitset with no field value slot) and the null bit was unset, soappend_fieldtreated the field as non-null and attempted to read 8 bytes past the end of the buffer. Fixed to use 16 bytes with bit 0 set to properly represent a null field.pull_requesttrigger now that the upstream cargo nightly regression is resolvedHow are these changes tested?
The existing
test_append_null_struct_field_to_struct_buildertest is the fix itself — it was the source of the Miri UB. The debug assertion will cause a panic in debug/test builds if any future test constructs an undersized row buffer.