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[SDK:REACTOS] probe.h!ProbeAndCaptureUnicodeString(): Validate USTRings and reject them if malformed.

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Make this actually the default, and only fall back to our old behaviour
of tolerating and fixing malformed strings only if a specific
`PROBE_USTR_TOLERATE_MALFORMED_STRINGS` is defined.

Somewhat an addendum to commit 0d26bbf4b5.
This commit is contained in:
Hermès Bélusca-Maïto
2025-11-29 22:12:45 +01:00
parent 9d29523180
commit 269bc1e7d2
1 changed files with 22 additions and 9 deletions
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31
sdk/include/reactos/probe.h
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@@ -163,6 +163,25 @@ ProbeAndCaptureUnicodeString(
#endif
if (Dest->Buffer != NULL)
{
#ifdef PROBE_USTR_TOLERATE_MALFORMED_STRINGS
if (Dest->Length % sizeof(WCHAR))
Dest->Length--;
if (Dest->Length > Dest->MaximumLength)
Dest->Length = Dest->MaximumLength;
#else
// REMARK: Ideally we should use RtlValidateUnicodeString() or ntstrsafe.h's
// RtlUnicodeStringValidate(Ex), but the code below performs the same checks.
// Also, UNICODE_STRING_MAX_CHARS == default NTSTRSAFE_UNICODE_STRING_MAX_CCH.
if (Dest->Length % sizeof(WCHAR) != 0 ||
Dest->MaximumLength % sizeof(WCHAR) != 0 ||
Dest->Length > Dest->MaximumLength ||
Dest->MaximumLength > UNICODE_STRING_MAX_CHARS * sizeof(WCHAR) ||
(Dest->Buffer == NULL && (Dest->Length != 0 || Dest->MaximumLength != 0)))
{
Status = STATUS_INVALID_PARAMETER;
_SEH2_LEAVE;
}
#endif
if (Dest->Length != 0)
{
ProbeForRead(Dest->Buffer, Dest->Length, sizeof(WCHAR));
@@ -183,18 +202,12 @@ ProbeAndCaptureUnicodeString(
/* Set it as the buffer */
Dest->Buffer = Buffer;
if (Dest->Length % sizeof(WCHAR))
{
Dest->Length--;
}
#ifdef PROBE_USTR_TOLERATE_MALFORMED_STRINGS
if (Dest->Length >= UNICODE_STRING_MAX_BYTES)
{
Dest->MaximumLength = Dest->Length;
}
else
{
Dest->MaximumLength = Dest->Length + sizeof(WCHAR);
}
#endif
Dest->MaximumLength = Dest->Length + sizeof(WCHAR);
}
else
{