[PATCH v3 0/1] MR7082: ntdll: Return an error if count is zero in NtRemoveIoCompletionEx.

[Alex Henrie (＠alexhenrie)]

Without this check, the return value is undefined.

--
  v3: ntdll: Return an error if count is zero in NtRemoveIoCompletionEx.

https://gitlab.winehq.org/wine/wine/-/merge_requests/7082

[PATCH v3 1/1] ntdll: Return an error if count is zero in NtRemoveIoCompletionEx.

[Alex Henrie]

From: Alex Henrie

Without this check, the return value is undefined.
---
 dlls/ntdll/tests/file.c | 5 +++++
 dlls/ntdll/unix/sync.c  | 2 ++
 dlls/wow64/file.c       | 6 +++++-
 3 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/dlls/ntdll/tests/file.c b/dlls/ntdll/tests/file.c
index 02bdf67796d..8465ad4543a 100644
--- a/dlls/ntdll/tests/file.c
+++ b/dlls/ntdll/tests/file.c
@@ -1039,6 +1039,11 @@ static void test_set_io_completion(void)
         return;
     }

+    count = 0xdeadbeef;
+    res = pNtRemoveIoCompletionEx( h, info, 0, &count, &timeout, FALSE );
+    ok( res == STATUS_INVALID_PARAMETER, "NtRemoveIoCompletionEx failed: %#lx\n", res );
+    ok( count == 0xdeadbeef, "wrong count %lu\n", count );
+
     count = 0xdeadbeef;
     res = pNtRemoveIoCompletionEx( h, info, 2, &count, &timeout, FALSE );
     ok( res == STATUS_TIMEOUT, "NtRemoveIoCompletionEx failed: %#lx\n", res );
diff --git a/dlls/ntdll/unix/sync.c b/dlls/ntdll/unix/sync.c
index d486b50001d..bc2aa0271a1 100644
--- a/dlls/ntdll/unix/sync.c
+++ b/dlls/ntdll/unix/sync.c
@@ -2081,6 +2081,8 @@ NTSTATUS WINAPI NtRemoveIoCompletionEx( HANDLE handle, FILE_IO_COMPLETION_INFORM

TRACE( "%p %p %u %p %p %u\n", handle, info, (int)count, written, timeout, alertable );

+    if (!count) return STATUS_INVALID_PARAMETER;
+
     while (i < count)
     {
         SERVER_START_REQ( remove_completion )
diff --git a/dlls/wow64/file.c b/dlls/wow64/file.c
index 0afd02a2a7c..d3358000def 100644
--- a/dlls/wow64/file.c
+++ b/dlls/wow64/file.c
@@ -751,7 +751,11 @@ NTSTATUS WINAPI wow64_NtRemoveIoCompletionEx( UINT *args )

NTSTATUS status;
     ULONG i;
-    FILE_IO_COMPLETION_INFORMATION *info = Wow64AllocateTemp( count * sizeof(*info) );
+    FILE_IO_COMPLETION_INFORMATION *info;
+
+    if (!count) return STATUS_INVALID_PARAMETER;
+
+    info = Wow64AllocateTemp( count * sizeof(*info) );

status = NtRemoveIoCompletionEx( handle, info, count, written, timeout, alertable );
     for (i = 0; i < *written; i++)

[Alex Henrie (＠alexhenrie)]

On Tue Jan  7 07:23:22 2025 +0000, Jinoh Kang wrote:
> Would you implement the check at `wow64_NtRemoveIoCompletionEx` side as well?

Done. I need to remember to check new wow64 mode when changing ntdll functions from now on.