1 files changed, 6 insertions, 1 deletions

diff --git a/include/linux/ptr_ring.h b/include/linux/ptr_ring.h
index 6866df4f31b5..13fb06a103c6 100644
--- a/include/linux/ptr_ring.h
+++ b/include/linux/ptr_ring.h
@@ -447,7 +447,12 @@ static inline int ptr_ring_consume_batched_bh(struct ptr_ring *r,
 
 static inline void **__ptr_ring_init_queue_alloc(unsigned int size, gfp_t gfp)
 {
-        return kcalloc(size, sizeof(void *), gfp);
+        /* Allocate an extra dummy element at end of ring to avoid consumer head
+         * or produce head access past the end of the array. Possible when
+         * producer/consumer operations and __ptr_ring_peek operations run in
+         * parallel.
+         */
+        return kcalloc(size + 1, sizeof(void *), gfp);
 }
 
 static inline void __ptr_ring_set_size(struct ptr_ring *r, int size)