AI: HTTP-FLV: Fix heap-use-after-free crash during stream unmount. v6.0.171 v7.0.50 (#4432)

## Summary
Fixes a critical heap-use-after-free crash in HTTP-FLV streaming that
occurs when a client requests a stream while it's being unmounted
asynchronously.

## Problem
- **Issue**: #4429 - Heap-use-after-free crash in
`SrsLiveStream::serve_http()`
- **Root Cause**: Race condition between coroutines in single-threaded
SRS server:
1. **Coroutine A**: HTTP client requests FLV stream → `serve_http()`
starts
2. **Coroutine B**: RTMP publisher disconnects → triggers async stream
destruction
3. **Async Worker**: Destroys `SrsLiveStream` object while Coroutine A
is yielded
  4. **Coroutine A**: Resumes and accesses freed memory → **CRASH**

## Solution
1. **Early viewer registration**: Add HTTP connection to `viewers_` list
immediately in `serve_http()` before any I/O operations that could yield
2. **Lifecycle protection**: Split `serve_http()` into wrapper and
implementation to ensure proper viewer management
3. **Stream availability checks**: Add fast checks for stream disposal
state before critical operations
4. **Improved error handling**: Convert warnings to fatal errors when
trying to free alive streams

## Key Changes
- **`SrsLiveStream::serve_http()`**: Now immediately registers viewer
and delegates to `serve_http_impl()`
- **`SrsLiveStream::serve_http_impl()`**: Contains the actual HTTP
serving logic
- **`SrsHttpStreamDestroy::call()`**: Enhanced error handling and longer
wait timeout
- **Stream state validation**: Added checks for `entry->enabled` before
proceeding with stream operations

Fixes #4429

trunk/doc/CHANGELOG.md

@@ -7,6 +7,7 @@ The changelog for SRS.
 <a name="v7-changes"></a>
 
 ## SRS 7.0 Changelog
+* v7.0, 2025-08-11, Merge [#4432](https://github.com/ossrs/srs/pull/4432): AI: HTTP-FLV: Fix heap-use-after-free crash during stream unmount. v7.0.50 (#4432)
 * v7.0, 2025-07-28, Merge [#4245](https://github.com/ossrs/srs/pull/4245): Allow Forward to be configured with Env Var. v7.0.49 (#4245)
 * v7.0, 2025-07-16, Merge [#4295](https://github.com/ossrs/srs/pull/4295): RTC: audio packet jitter buffer. v7.0.48 (#4295)
 * v7.0, 2025-07-11, Merge [#4333](https://github.com/ossrs/srs/pull/4333): NEW PROTOCOL: Support viewing stream over RTSP. v7.0.47 (#4333)
@@ -60,6 +61,7 @@ The changelog for SRS.
 <a name="v6-changes"></a>
 
 ## SRS 6.0 Changelog
+* v6.0, 2025-08-11, Merge [#4432](https://github.com/ossrs/srs/pull/4432): AI: HTTP-FLV: Fix heap-use-after-free crash during stream unmount. v6.0.171 (#4432)
 * v6.0, 2025-07-28, Merge [#4245](https://github.com/ossrs/srs/pull/4245): Allow Forward to be configured with Env Var. v6.0.170 (#4245)
 * v6.0, 2025-07-10, Merge [#4414](https://github.com/ossrs/srs/pull/4414): Fix H.264 B-frame detection logic to comply with specification. v6.0.169 (#4414)
 * v6.0, 2025-06-04, Merge [#4325](https://github.com/ossrs/srs/pull/4325): fix bug: loop transcoding #3516. v6.0.168 (#4325)

trunk/src/app/srs_app_http_stream.cpp

@@ -619,6 +619,26 @@ srs_error_t SrsLiveStream::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage
 {
     srs_error_t err = srs_success;
 
+    SrsHttpMessage* hr = dynamic_cast<SrsHttpMessage*>(r);
+    SrsHttpConn* hc = dynamic_cast<SrsHttpConn*>(hr->connection());
+
+    // Add the viewer to the viewers list.
+    viewers_.push_back(hc);
+
+    err = serve_http_impl(w, r);
+
+    // Remove viewer from the viewers list.
+    vector<ISrsExpire*>::iterator it = std::find(viewers_.begin(), viewers_.end(), hc);
+    srs_assert (it != viewers_.end());
+    viewers_.erase(it);
+    
+    return err;
+}
+
+srs_error_t SrsLiveStream::serve_http_impl(ISrsHttpResponseWriter* w, ISrsHttpMessage* r)
+{
+    srs_error_t err = srs_success;
+
     SrsHttpMessage* hr = dynamic_cast<SrsHttpMessage*>(r);
     SrsHttpConn* hc = dynamic_cast<SrsHttpConn*>(hr->connection());
     SrsHttpxConn* hxc = dynamic_cast<SrsHttpxConn*>(hc->handler());
@@ -651,6 +671,11 @@ srs_error_t SrsLiveStream::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage
         return srs_error_wrap(err, "http hook");
     }
 
+    // Fast check whether stream is still available.
+    if (!entry->enabled) {
+        return srs_error_new(ERROR_RTMP_STREAM_NOT_FOUND, "stream not found");
+    }
+
     // Always try to create the source, because http handler won't create it.
     SrsSharedPtr<SrsLiveSource> live_source;
     if ((err = _srs_sources->fetch_or_create(req, server_, live_source)) != srs_success) {
@@ -673,16 +698,13 @@ srs_error_t SrsLiveStream::serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage
     // object is not alive.
     SrsUniquePtr<SrsLiveConsumer> consumer(consumer_raw);
 
-    // Add the viewer to the viewers list.
-    viewers_.push_back(hc);
+    // Fast check whether stream is still available.
+    if (!entry->enabled) {
+        return srs_error_new(ERROR_RTMP_STREAM_NOT_FOUND, "stream not found");
+    }
 
     // Serve the viewer connection.
     err = do_serve_http(live_source.get(), consumer.get(), w, r);
-
-    // Remove viewer from the viewers list.
-    vector<ISrsExpire*>::iterator it = std::find(viewers_.begin(), viewers_.end(), hc);
-    srs_assert (it != viewers_.end());
-    viewers_.erase(it);
     
     // Do hook after serving.
     http_hooks_on_stop(r);
@@ -1321,7 +1343,7 @@ srs_error_t SrsHttpStreamDestroy::call()
 
     // Wait for cache and stream to stop.
     int i = 0;
-    for (; i < 1024; i++) {
+    for (; i < 3000; i++) {
         if (!cache->alive() && !stream->alive()) {
             break;
         }
@@ -1329,7 +1351,9 @@ srs_error_t SrsHttpStreamDestroy::call()
     }
 
     if (cache->alive() || stream->alive()) {
-        srs_warn("http: try to free a alive stream, cache=%d, stream=%d", cache->alive(), stream->alive());
+        srs_error("http: try to free an alive stream, sid=%s, cache=%d, stream=%d", 
+            sid_.c_str(), cache->alive(), stream->alive());
+        srs_assert(false);
     }
 
     // Remove the entry from handlers.

trunk/src/app/srs_app_http_stream.hpp

@@ -198,6 +198,9 @@ public:
     virtual srs_error_t update_auth(SrsRequest* r);
 public:
     virtual srs_error_t serve_http(ISrsHttpResponseWriter* w, ISrsHttpMessage* r);
+private:
+    srs_error_t serve_http_impl(ISrsHttpResponseWriter* w, ISrsHttpMessage* r);
+public:
     virtual bool alive();
 // Interface ISrsExpire
 public:

trunk/src/core/srs_core_version6.hpp

@@ -9,6 +9,6 @@
 
 #define VERSION_MAJOR       6
 #define VERSION_MINOR       0
-#define VERSION_REVISION    170
+#define VERSION_REVISION    171
 
 #endif

trunk/src/core/srs_core_version7.hpp

@@ -9,6 +9,6 @@
 
 #define VERSION_MAJOR       7
 #define VERSION_MINOR       0
-#define VERSION_REVISION    49
+#define VERSION_REVISION    50
 
 #endif