Re: [PATCH] fs/ntfs3: reject evcn == U64_MAX in mi_enum_attr()

Zhan Xusheng
2026-04-24T13:20:40Z

Hi David,

That would reject the svcn == evcn case, which represents a
single-cluster extent (e.g. svcn=0, evcn=0) and is currently
treated as valid.

The original check allows svcn == evcn + 1 (empty range), so the
condition is strictly "greater than", not "greater than or equal".

The issue here is the overflow of (evcn + 1) when evcn == U64_MAX,
which turns the check into "svcn > 0" and incorrectly allows
svcn == 0.

My patch preserves the existing semantics and only adds the
missing U64_MAX guard.

Thanks,
Zhan Xusheng