8203182: Release session if initialization of SunPKCS11 Signature fails

Summary: Ensure session is properly released in P11Signature class
Reviewed-by: valeriep
Contributed-by: NMartin Balao <mbalao@redhat.com>

src/share/classes/sun/security/pkcs11/P11Signature.java

@@ -257,6 +257,7 @@ final class P11Signature extends SignatureSpi {
             session = token.killSession(session);
             return;
         }
+        try {
             // "cancel" operation by finishing it
             // XXX make sure all this always works correctly
             if (mode == M_SIGN) {
@@ -299,6 +300,9 @@ final class P11Signature extends SignatureSpi {
                     // XXX check error code
                 }
             }
+        } finally {
+            session = token.releaseSession(session);
+        }
     }
 
     // assumes current state is initialized == false
@@ -316,6 +320,8 @@ final class P11Signature extends SignatureSpi {
             }
             initialized = true;
         } catch (PKCS11Exception e) {
+            // release session when initialization failed
+            session = token.releaseSession(session);
             throw new ProviderException("Initialization failed", e);
         }
         if (bytesProcessed != 0) {
@@ -476,6 +482,8 @@ final class P11Signature extends SignatureSpi {
                 }
                 bytesProcessed += len;
             } catch (PKCS11Exception e) {
+                initialized = false;
+                session = token.releaseSession(session);
                 throw new ProviderException(e);
             }
             break;
@@ -523,6 +531,8 @@ final class P11Signature extends SignatureSpi {
                 bytesProcessed += len;
                 byteBuffer.position(ofs + len);
             } catch (PKCS11Exception e) {
+                initialized = false;
+                session = token.releaseSession(session);
                 throw new ProviderException("Update failed", e);
             }
             break;