Alistair Leslie-Hughes : secur32: QueryContextAttributesW check for valid object before use.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: cbddd3930b4b186c7f0034e67abfbfcf18f423b1
URL:    https://gitlab.winehq.org/wine/wine/-/commit/cbddd3930b4b186c7f0034e67abfbfc...

Author: Alistair Leslie-Hughes 
Date:   Tue Jan 31 12:37:09 2023 +1100

secur32: QueryContextAttributesW check for valid object before use.

---

dlls/secur32/schannel.c       | 4 ++--
 dlls/secur32/tests/schannel.c | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/dlls/secur32/schannel.c b/dlls/secur32/schannel.c
index 6b5df3520a7..6b4be497f30 100644
--- a/dlls/secur32/schannel.c
+++ b/dlls/secur32/schannel.c
@@ -1149,8 +1149,8 @@ static SECURITY_STATUS SEC_ENTRY schan_QueryContextAttributesW(
     TRACE("context_handle %p, attribute %#lx, buffer %p\n",
             context_handle, attribute, buffer);

-    if (!context_handle) return SEC_E_INVALID_HANDLE;
-    ctx = schan_get_object(context_handle->dwLower, SCHAN_HANDLE_CTX);
+    if (!context_handle || !(ctx = schan_get_object(context_handle->dwLower, SCHAN_HANDLE_CTX)))
+        return SEC_E_INVALID_HANDLE;

switch(attribute)
     {
diff --git a/dlls/secur32/tests/schannel.c b/dlls/secur32/tests/schannel.c
index f0b0b20b08a..5153c9b4a1e 100644
--- a/dlls/secur32/tests/schannel.c
+++ b/dlls/secur32/tests/schannel.c
@@ -1529,6 +1529,10 @@ static void test_communication(void)

done:
     DeleteSecurityContext(&context);
+
+    status = QueryContextAttributesW(&context, SECPKG_ATTR_REMOTE_CERT_CONTEXT, (void*)&cert);
+    ok(status == SEC_E_INVALID_HANDLE, "QueryContextAttributesW(SECPKG_ATTR_REMOTE_CERT_CONTEXT) got %08lx\n", status);
+
     FreeCredentialsHandle(&cred_handle);

CertFreeCertificateContext(cert);