[PATCH 0/1] MR2685: msvcrt: Fix crash when rethrowing after a non-C++ exception on x86_64.

[Brendan Shanks (＠bshanks)]

This fixes a crash seen with the .NET Framework 3.5 SP1 installer in a 64-bit prefix where `ServiceModelReg.exe` throws a C++ exception, it's rethrown again, then a CLR exception (`0xe0434f4d`) exception is thrown, and finally there's another C++ rethrow.

At the last rethrow, `cxx_frame_handler()` detects the rethrow and sets `*rec` to the previous exception record, which is the CLR exception, not the C++ exception. If `+seh` is enabled, it then assumes `*rec` is a C++ exception and tries to TRACE info about it, which crashes.

Move the rethrow detection before the exception type check, so the TRACEs are not done.

[PATCH 1/1] msvcrt: Fix crash when rethrowing after a non-C++ exception on x86_64.

[Brendan Shanks]

From: Brendan Shanks

---
 dlls/msvcrt/except_x86_64.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/dlls/msvcrt/except_x86_64.c b/dlls/msvcrt/except_x86_64.c
index d40b9985cd2..b07a7b83772 100644
--- a/dlls/msvcrt/except_x86_64.c
+++ b/dlls/msvcrt/except_x86_64.c
@@ -579,14 +579,14 @@ static DWORD cxx_frame_handler(EXCEPTION_RECORD *rec, ULONG64 frame,
         return ExceptionContinueSearch;
     }

+    if (rec->ExceptionCode == CXX_EXCEPTION &&
+        (!rec->ExceptionInformation[1] && !rec->ExceptionInformation[2]))
+    {
+        TRACE("rethrow detected.\n");
+        *rec = *msvcrt_get_thread_data()->exc_record;
+    }
     if (rec->ExceptionCode == CXX_EXCEPTION)
     {
-        if (!rec->ExceptionInformation[1] && !rec->ExceptionInformation[2])
-        {
-            TRACE("rethrow detected.\n");
-            *rec = *msvcrt_get_thread_data()->exc_record;
-        }
-
         exc_type = (cxx_exception_type *)rec->ExceptionInformation[2];

if (TRACE_ON(seh))

[PATCH 0/1] MR2685: msvcrt: Fix crash when rethrowing after a non-C++ exception on x86_64. - approved

[Piotr Caban (＠piotr)]

This merge request was approved by Piotr Caban.