[dpdk-dev] [PATCH] hash: fix out-of-bound write while freeing key slot

[Honnappa Nagarahalli]

Add a debug check for out-of-bound write while freeing the key slot.

Coverity issue: 325733
Fixes: e605a1d36ca7 ("hash: add lock-free r/w concurrency")
Cc: honnappa.nagaraha...@arm.com

Signed-off-by: Honnappa Nagarahalli <honnappa.nagaraha...@arm.com>
Reviewed-by: Steve Capper <steve.cap...@arm.com>
Reviewed-by: Gavin Hu <gavin...@arm.com>
---
 lib/librte_hash/rte_cuckoo_hash.c |  4 ++++
 lib/librte_hash/rte_cuckoo_hash.h | 11 +++++++++++
 2 files changed, 15 insertions(+)

diff --git a/lib/librte_hash/rte_cuckoo_hash.c 
b/lib/librte_hash/rte_cuckoo_hash.c
index 5ddcccd87..c35a60266 100644
--- a/lib/librte_hash/rte_cuckoo_hash.c
+++ b/lib/librte_hash/rte_cuckoo_hash.c
@@ -1272,6 +1272,9 @@ remove_entry(const struct rte_hash *h, struct 
rte_hash_bucket *bkt, unsigned i)
                        n_slots = rte_ring_mp_enqueue_burst(h->free_slots,
                                                cached_free_slots->objs,
                                                LCORE_CACHE_SIZE, NULL);
+                       ERR_IF_TRUE((n_slots == 0),
+                               "%s: could not enqueue free slots in global 
ring\n",
+                               __func__);
                        cached_free_slots->len -= n_slots;
                }
                /* Put index of new free slot in cache. */
@@ -1477,6 +1480,7 @@ rte_hash_free_key_with_position(const struct rte_hash *h,
                        n_slots = rte_ring_mp_enqueue_burst(h->free_slots,
                                                cached_free_slots->objs,
                                                LCORE_CACHE_SIZE, NULL);
+                       RETURN_IF_TRUE((n_slots == 0), -EFAULT);
                        cached_free_slots->len -= n_slots;
                }
                /* Put index of new free slot in cache. */
diff --git a/lib/librte_hash/rte_cuckoo_hash.h 
b/lib/librte_hash/rte_cuckoo_hash.h
index 5dfbbc48b..eacdaa8d4 100644
--- a/lib/librte_hash/rte_cuckoo_hash.h
+++ b/lib/librte_hash/rte_cuckoo_hash.h
@@ -29,6 +29,17 @@
 #define RETURN_IF_TRUE(cond, retval)
 #endif
 
+#if defined(RTE_LIBRTE_HASH_DEBUG)
+#define ERR_IF_TRUE(cond, fmt, args...) do { \
+       if (cond) { \
+               RTE_LOG(ERR, HASH, fmt, ##args); \
+               return; \
+       } \
+} while (0)
+#else
+#define ERR_IF_TRUE(cond, fmt, args...)
+#endif
+
 #include <rte_hash_crc.h>
 #include <rte_jhash.h>
 
-- 
2.17.1