From 1d8c4ef6a90b87f3b516e9310a0e53bf1425a780 Mon Sep 17 00:00:00 2001
From: c30013472 <chengqguangqiang1@huawei.com>
Date: Wed, 29 May 2024 15:25:31 +0800
Subject: [PATCH] Fix possible use-after-free in SSL_free_buffers

Related to CVE-2024-4741

Reference:https://gitee.com/openeuler/openssl/commit/1d8c4ef6a90b87f3b516e9310a0e53bf1425a780
Conflict:rec_layer_s3.c,ssl3_buffer.c,ssl_lib.c

Signed-off-by: c30013472 <chengqguangqiang1@huawei.com>
---
 test/sslbuffertest.c      | 167 +++++++++++++++++++++++++++++++++++++-
 test/ssltestlib.c         |  25 ++++++
 test/ssltestlib.h         |   1 +
 7 files changed, 213 insertions(+), 1 deletion(-)

diff --git a/test/sslbuffertest.c b/test/sslbuffertest.c
index b5f815f7db..f57db36630 100644
--- a/test/sslbuffertest.c
+++ b/test/sslbuffertest.c
@@ -12,7 +12,7 @@
 #include <openssl/ssl.h>
 #include <openssl/bio.h>
 #include <openssl/err.h>
-
+#include <openssl/engine.h>
 #include "../ssl/packet_local.h"
 
 #include "ssltestlib.h"
@@ -157,6 +157,166 @@ int global_init(void)
     return 1;
 }
 
+/*
+ * Test that attempting to free the buffers at points where they cannot be freed
+ * works as expected
+ * Test 0: Attempt to free buffers after a full record has been processed, but
+ *         the application has only performed a partial read
+ * Test 1: Attempt to free buffers after only a partial record header has been
+ *         received
+ * Test 2: Attempt to free buffers after a full record header but no record body
+ * Test 3: Attempt to free buffers after a full record hedaer and partial record
+ *         body
+ * Test 4-7: We repeat tests 0-3 but including data from a second pipelined
+ *           record
+ */
+static int test_free_buffers(int test)
+{
+    int result = 0;
+    SSL *serverssl = NULL, *clientssl = NULL;
+    const char testdata[] = "Test data";
+    char buf[120];
+    size_t written, readbytes;
+    int i, pipeline = test > 3;
+    ENGINE *e = NULL;
+
+    if (pipeline) {
+        e = load_dasync();
+        if (e == NULL)
+            goto end;
+        test -= 4;
+    }
+
+    if (!TEST_true(create_ssl_objects(serverctx, clientctx, &serverssl,
+                                      &clientssl, NULL, NULL)))
+        goto end;
+
+    if (pipeline) {
+        if (!TEST_true(SSL_set_cipher_list(serverssl, "AES128-SHA"))
+                || !TEST_true(SSL_set_max_proto_version(serverssl,
+                                                        TLS1_2_VERSION))
+                || !TEST_true(SSL_set_max_pipelines(serverssl, 2)))
+            goto end;
+    }
+
+    if (!TEST_true(create_ssl_connection(serverssl, clientssl,
+                                         SSL_ERROR_NONE)))
+        goto end;
+
+
+    /*
+     * For the non-pipeline case we write one record. For pipelining we write
+     * two records.
+     */
+    for (i = 0; i <= pipeline; i++) {
+        if (!TEST_true(SSL_write_ex(clientssl, testdata, strlen(testdata),
+                                    &written)))
+            goto end;
+    }
+
+    if (test == 0) {
+        size_t readlen = 1;
+
+        /*
+         * Deliberately only read the first byte - so the remaining bytes are
+         * still buffered. In the pipelining case we read as far as the first
+         * byte from the second record.
+         */
+        if (pipeline)
+            readlen += strlen(testdata);
+
+        if (!TEST_true(SSL_read_ex(serverssl, buf, readlen, &readbytes))
+                || !TEST_size_t_eq(readlen, readbytes))
+            goto end;
+    } else {
+        BIO *tmp;
+        size_t partial_len;
+
+        /* Remove all the data that is pending for read by the server */
+        tmp = SSL_get_rbio(serverssl);
+        if (!TEST_true(BIO_read_ex(tmp, buf, sizeof(buf), &readbytes))
+                || !TEST_size_t_lt(readbytes, sizeof(buf))
+                || !TEST_size_t_gt(readbytes, SSL3_RT_HEADER_LENGTH))
+            goto end;
+
+        switch(test) {
+        case 1:
+            partial_len = SSL3_RT_HEADER_LENGTH - 1;
+            break;
+        case 2:
+            partial_len = SSL3_RT_HEADER_LENGTH;
+            break;
+        case 3:
+            partial_len = readbytes - 1;
+            break;
+        default:
+            TEST_error("Invalid test index");
+            goto end;
+        }
+
+        if (pipeline) {
+            /* We happen to know the first record is 57 bytes long */
+            const size_t first_rec_len = 57;
+
+            if (test != 3)
+                partial_len += first_rec_len;
+
+            /*
+             * Sanity check. If we got the record len right then this should
+             * never fail.
+             */
+            if (!TEST_int_eq(buf[first_rec_len], SSL3_RT_APPLICATION_DATA))
+                goto end;
+        }
+        /*
+         * Put back just the partial record (plus the whole initial record in
+         * the pipelining case)
+         */
+        if (!TEST_true(BIO_write_ex(tmp, buf, partial_len, &written)))
+            goto end;
+
+        if (pipeline) {
+            /*
+             * Attempt a read. This should pass but only return data from the
+             * first record. Only a partial record is available for the second
+             * record.
+             */
+            if (!TEST_true(SSL_read_ex(serverssl, buf, sizeof(buf),
+                                        &readbytes))
+                    || !TEST_size_t_eq(readbytes, strlen(testdata)))
+                goto end;
+        } else {
+            /*
+            * Attempt a read. This should fail because only a partial record is
+            * available.
+            */
+            if (!TEST_false(SSL_read_ex(serverssl, buf, sizeof(buf),
+                                        &readbytes)))
+                goto end;
+        }
+    }
+
+    /*
+     * Attempting to free the buffers at this point should fail because they are
+     * still in use
+     */
+    if (!TEST_false(SSL_free_buffers(serverssl)))
+        goto end;
+
+    result = 1;
+ end:
+    SSL_free(clientssl);
+    SSL_free(serverssl);
+#ifndef OPENSSL_NO_DYNAMIC_ENGINE
+    if (e != NULL) {
+        ENGINE_unregister_ciphers(e);
+        ENGINE_finish(e);
+        ENGINE_free(e);
+    }
+#endif
+    return result;
+}
+
 int setup_tests(void)
 {
     char *cert, *pkey;
@@ -173,6 +333,11 @@ int setup_tests(void)
     }
 
     ADD_ALL_TESTS(test_func, 9);
+#if !defined(OPENSSL_NO_TLS1_2) && !defined(OPENSSL_NO_DYNAMIC_ENGINE)
+    ADD_ALL_TESTS(test_free_buffers, 8);
+#else
+    ADD_ALL_TESTS(test_free_buffers, 4);
+#endif
     return 1;
 }
 
diff --git a/test/ssltestlib.c b/test/ssltestlib.c
index 422787b0f5..b1da6866c0 100644
--- a/test/ssltestlib.c
+++ b/test/ssltestlib.c
@@ -9,6 +9,7 @@
 
 #include <string.h>
 
+#include <openssl/engine.h>
 #include "internal/nelem.h"
 #include "ssltestlib.h"
 #include "testutil.h"
@@ -975,3 +976,27 @@ void shutdown_ssl_connection(SSL *serverssl, SSL *clientssl)
     SSL_free(serverssl);
     SSL_free(clientssl);
 }
+
+ENGINE *load_dasync(void)
+{
+#if !defined(OPENSSL_NO_TLS1_2) && !defined(OPENSSL_NO_DYNAMIC_ENGINE)
+    ENGINE *e;
+
+    if (!TEST_ptr(e = ENGINE_by_id("dasync")))
+        return NULL;
+
+    if (!TEST_true(ENGINE_init(e))) {
+        ENGINE_free(e);
+        return NULL;
+    }
+
+    if (!TEST_true(ENGINE_register_ciphers(e))) {
+        ENGINE_free(e);
+        return NULL;
+    }
+
+    return e;
+#else
+    return NULL;
+#endif
+}
diff --git a/test/ssltestlib.h b/test/ssltestlib.h
index 8f0a1b5308..38f97a8cbd 100644
--- a/test/ssltestlib.h
+++ b/test/ssltestlib.h
@@ -54,4 +54,5 @@ typedef struct mempacket_st MEMPACKET;
 
 DEFINE_STACK_OF(MEMPACKET)
 
+ENGINE *load_dasync(void);
 #endif /* OSSL_TEST_SSLTESTLIB_H */
-- 
2.27.0

