Fix: check reference counts for overflow

[lttng-modules.git] / lib / ringbuffer / ring_buffer_frontend.c

diff --git a/lib/ringbuffer/ring_buffer_frontend.c b/lib/ringbuffer/ring_buffer_frontend.c
index c4b797ce8af76faf9ba5209d054b89fb42326656..dbe52c157c71be0ec560bbc6b97dc77d1b1e27ea 100644 (file)
--- a/lib/ringbuffer/ring_buffer_frontend.c
+++ b/lib/ringbuffer/ring_buffer_frontend.c
@@ -61,6 +61,7 @@
 #include "../../wrapper/ringbuffer/iterator.h"
 #include "../../wrapper/ringbuffer/nohz.h"
 #include "../../wrapper/atomic.h"
+#include "../../wrapper/kref.h"
 #include "../../wrapper/percpu-defs.h"
 
 /*
@@ -793,7 +794,10 @@ int lib_ring_buffer_open_read(struct lib_ring_buffer *buf)
 
        if (!atomic_long_add_unless(&buf->active_readers, 1, 1))
                return -EBUSY;
-       kref_get(&chan->ref);
+       if (!lttng_kref_get(&chan->ref)) {
+               atomic_long_dec(&buf->active_readers);
+               return -EOVERFLOW;
+       }
        lttng_smp_mb__after_atomic();
        return 0;
 }