[PATCH 3/3] ntdll: Validate xstate alignment in validate_context_xstate().

[Paul Gofman]

From: Paul Gofman <pgofman at codeweavers.com>

Signed-off-by: Paul Gofman <pgofman at codeweavers.com>
---
 dlls/ntdll/tests/exception.c | 14 ++++++++++++++
 dlls/ntdll/unix/thread.c     |  2 ++
 2 files changed, 16 insertions(+)

diff --git a/dlls/ntdll/tests/exception.c b/dlls/ntdll/tests/exception.c
index 820e435bc1b..06a38756f80 100644
--- a/dlls/ntdll/tests/exception.c
+++ b/dlls/ntdll/tests/exception.c
@@ -9445,6 +9445,7 @@ static void test_extended_context(void)
     CONTEXT_EX *context_ex;
     CONTEXT *context;
     unsigned data[8];
+    NTSTATUS status;
     HANDLE thread;
     ULONG64 mask;
     XSTATE *xs;
@@ -10227,6 +10228,19 @@ static void test_extended_context(void)
     thread = CreateThread(NULL, 0, test_extended_context_thread, 0, CREATE_SUSPENDED, NULL);
     ok(!!thread, "Failed to create thread.\n");
 
+    /* Unaligned xstate. */
+    length = sizeof(context_buffer);
+    memset(context_buffer, 0xcc, sizeof(context_buffer));
+    bret = pInitializeContext(context_buffer, CONTEXT_FULL | CONTEXT_XSTATE | CONTEXT_FLOATING_POINT,
+            &context, &length);
+    ok(bret, "Got unexpected bret %#x.\n", bret);
+    context_ex = (CONTEXT_EX *)(context + 1);
+    context_ex->XState.Offset += 0x10;
+    status = pNtGetContextThread(thread, context);
+    ok(status == STATUS_INVALID_PARAMETER, "Unexpected status %#lx.\n", status);
+    status = pNtGetContextThread(GetCurrentThread(), context);
+    ok(status == STATUS_INVALID_PARAMETER, "Unexpected status %#lx.\n", status);
+
     bret = pInitializeContext(context_buffer, CONTEXT_FULL | CONTEXT_XSTATE | CONTEXT_FLOATING_POINT,
             &context, &length);
     ok(bret, "Got unexpected bret %#x.\n", bret);
diff --git a/dlls/ntdll/unix/thread.c b/dlls/ntdll/unix/thread.c
index b393315e6fe..00ee607a671 100644
--- a/dlls/ntdll/unix/thread.c
+++ b/dlls/ntdll/unix/thread.c
@@ -167,6 +167,8 @@ BOOL validate_context_xstate( CONTEXT *context )
         || context_ex->XState.Length > sizeof(XSTATE))
         return FALSE;
 
+    if (((ULONG_PTR)context_ex + context_ex->XState.Offset) & 63) return FALSE;
+
     return TRUE;
 }
 
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/260