A descriptor replaced before the shared-memory path probe can otherwise
bypass the pinned-object identity check through native fallback. Compare
the negative probe's current file identity to the initial snapshot and
reject a mismatch. Exercise the earlier window with an ordinary file for
all six descriptor operations.
Confidence: high
Scope-risk: narrow
Tested: 18 Linux runtime tests with zero skips; 18 deterministic reuse scenarios; affected three patched modules; standalone ASan/UBSan; Clang analyzer; conventions and diff checks
Not-tested: Full project build/suite, Windows runtime, console hardware and titles
Directive: Identity checks do not synchronize the entire descriptor table or identify separate opens of the same inode
Keep guest creation-mask state in libc behind C-linkage helpers so NID
patching preserves the shared exports. Reject a pinned descriptor whose
file identity differs from the snapshot taken before classification.
Exercise close and reuse from another thread at both acquisition windows
for writes, resize and seek, and create temporary ordinary-file fixtures
so runtime tests work without the source tree.
Constraint: NID exemptions require the literal suffix at the end of the exported symbol
Confidence: high
Scope-risk: narrow
Tested: 18 targeted Linux runtime tests with zero skips; patched_libraries for libc/libkernel/libkernel_sys; standalone ASan/UBSan with warnings as errors; source-prefix-remapped fixtures; Clang analyzer and conventions
Not-tested: Full project build and library set, Windows runtime, console hardware and titles
Directive: Device/inode validation establishes file identity, not open-file-description identity