[PATCH v3 0/1] MR8043: ntdll: Align records retrieved by SystemProcessInformation.

[Bernhard Übelacker (＠bernhardu)]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55928

There is no application known, which fails because of this, it just triggers UndefinedBehaviorSanitizer.

--
  v3: ntdll: Align records retrieved by SystemProcessInformation.

https://gitlab.winehq.org/wine/wine/-/merge_requests/8043

[PATCH v3 1/1] ntdll: Align records retrieved by SystemProcessInformation.

[Bernhard Übelacker]

From: Bernhard Übelacker

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=55928
---
 dlls/ntdll/tests/info.c  | 2 ++
 dlls/ntdll/unix/system.c | 1 +
 dlls/wow64/system.c      | 1 +
 3 files changed, 4 insertions(+)

diff --git a/dlls/ntdll/tests/info.c b/dlls/ntdll/tests/info.c
index ac979760433..ee48a330400 100644
--- a/dlls/ntdll/tests/info.c
+++ b/dlls/ntdll/tests/info.c
@@ -662,6 +662,8 @@ static void test_query_process( BOOL extended )
             }
         }

+        ok(((ULONG_PTR)spi & 7) == 0, "Record is not aligned at 8 byte boundary. %p\n", spi);
+
         if (!spi->NextEntryOffset)
         {
             winetest_pop_context();
diff --git a/dlls/ntdll/unix/system.c b/dlls/ntdll/unix/system.c
index d3983c0dffb..0ff3d8182de 100644
--- a/dlls/ntdll/unix/system.c
+++ b/dlls/ntdll/unix/system.c
@@ -2879,6 +2879,7 @@ C_ASSERT( sizeof(struct process_info) <= sizeof(SYSTEM_PROCESS_INFORMATION) );

proc_len = sizeof(*nt_process) + server_process->thread_count * thread_info_size
                      + (name_len + 1) * sizeof(WCHAR);
+        proc_len = (proc_len + 7) & ~(ULONG_PTR)7;
         *len += proc_len;

if (*len <= size)
diff --git a/dlls/wow64/system.c b/dlls/wow64/system.c
index ffa82054b9a..fd10a0585ce 100644
--- a/dlls/wow64/system.c
+++ b/dlls/wow64/system.c
@@ -177,6 +177,7 @@ static NTSTATUS put_system_proc_info( SYSTEM_PROCESS_INFORMATION32 *info32,
             prev = proc32;
         }
         outpos += proc_len + proc->ProcessName.MaximumLength;
+        outpos = (outpos + 7) & ~(ULONG_PTR)7;
         inpos += proc->NextEntryOffset;
         if (!proc->NextEntryOffset) break;
     }

[Bernhard Übelacker (＠bernhardu)]

v3:
- Use ULONG_PTR for negation and casts.

[Bernhard Übelacker (＠bernhardu)]

On Wed May 14 15:59:42 2025 +0000, Paul Gofman wrote:
> Ah, great, thanks.
> You probably don't want to add #define ALIGN for one time use. I'd
> suggest to use a variable for (initially) unaligned result instead and
> just align without macros (also using it like ~(ULONG_PTR)7));

Thanks for the support, I resolved the macro and pushed a new version.

[Paul Gofman (＠gofman)]

Sorry, I didn't verify at once and the values are actually ULONG so casting alignment to ULONG_PTR is excessive. While also not too bad probably, not sure that worth changing and resending.

[PATCH v3 0/1] MR8043: ntdll: Align records retrieved by SystemProcessInformation. - approved

[Paul Gofman (＠gofman)]

This merge request was approved by Paul Gofman.