[reactos] 02/02: [INCLUDE] Safely handle odd & large lengths in ProbeAndCaptureUnicodeString.

[Thomas Faber]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=0d26bbf4b5c63ff58bd0e2...

commit 0d26bbf4b5c63ff58bd0e229753b6ff185e128cb
Author:     Thomas Faber [e-mail]
AuthorDate: Sun Dec 29 15:10:37 2019 +0100
Commit:     Thomas Faber [e-mail]
CommitDate: Sun Dec 29 15:22:10 2019 +0100

[INCLUDE] Safely handle odd & large lengths in ProbeAndCaptureUnicodeString.
---
 sdk/include/reactos/probe.h | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/sdk/include/reactos/probe.h b/sdk/include/reactos/probe.h
index 0aac83f065f..16ee4bd6e38 100644
--- a/sdk/include/reactos/probe.h
+++ b/sdk/include/reactos/probe.h
@@ -180,7 +180,18 @@ ProbeAndCaptureUnicodeString(OUT PUNICODE_STRING Dest,

/* Set it as the buffer */
                     Dest->Buffer = Buffer;
-                    Dest->MaximumLength = Dest->Length + sizeof(WCHAR);
+                    if (Dest->Length % sizeof(WCHAR))
+                    {
+                        Dest->Length--;
+                    }
+                    if (Dest->Length >= UNICODE_STRING_MAX_BYTES)
+                    {
+                        Dest->MaximumLength = Dest->Length;
+                    }
+                    else
+                    {
+                        Dest->MaximumLength = Dest->Length + sizeof(WCHAR);
+                    }
                 }
                 else
                 {