0024-net-ena-base-prevent-allocation-of-zero-sized-memory.patch

From d5fe29f02d748a043884f5762fb26cb291af3471 Mon Sep 17 00:00:00 2001
From: Igor Chauskin <igorch@amazon.com>
Date: Wed, 8 Apr 2020 10:28:54 +0200
Subject: [PATCH 24/27] net/ena/base: prevent allocation of zero sized memory

[ upstream commit 29dc10d9424ccf26a346387b0a707185e2432400 ]

rte_memzone_reserve() will reserve the biggest contiguous memzone
available if received 0 as size param.

Fixes: 9ba7981ec992 ("ena: add communication layer for DPDK")
Cc: stable@dpdk.org

Change-Id: I2f71119e93c5e9addd8c538820093f030066d690
Signed-off-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Guy Tzalik <gtzalik@amazon.com>
---
 drivers/net/ena/base/ena_plat_dpdk.h | 29 ++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/net/ena/base/ena_plat_dpdk.h b/drivers/net/ena/base/ena_plat_dpdk.h
index ac2c281297..57cf5078ea 100644
--- a/drivers/net/ena/base/ena_plat_dpdk.h
+++ b/drivers/net/ena/base/ena_plat_dpdk.h
@@ -205,15 +205,18 @@ extern rte_atomic32_t ena_alloc_cnt;
 
 #define ENA_MEM_ALLOC_COHERENT(dmadev, size, virt, phys, handle)	\
 	do {								\
-		const struct rte_memzone *mz;				\
-		char z_name[RTE_MEMZONE_NAMESIZE];			\
+		const struct rte_memzone *mz = NULL;			\
 		ENA_TOUCH(dmadev); ENA_TOUCH(handle);			\
-		snprintf(z_name, sizeof(z_name),			\
+		if (size > 0) {						\
+			char z_name[RTE_MEMZONE_NAMESIZE];		\
+			snprintf(z_name, sizeof(z_name),		\
 			 "ena_alloc_%d",				\
 			 rte_atomic32_add_return(&ena_alloc_cnt, 1));	\
-		mz = rte_memzone_reserve(z_name, size, SOCKET_ID_ANY,	\
-				RTE_MEMZONE_IOVA_CONTIG);		\
-		handle = mz;						\
+			mz = rte_memzone_reserve(z_name, size,		\
+					SOCKET_ID_ANY,			\
+					RTE_MEMZONE_IOVA_CONTIG);	\
+			handle = mz;					\
+		}							\
 		if (mz == NULL) {					\
 			virt = NULL;					\
 			phys = 0;					\
@@ -231,15 +234,17 @@ extern rte_atomic32_t ena_alloc_cnt;
 #define ENA_MEM_ALLOC_COHERENT_NODE(					\
 	dmadev, size, virt, phys, mem_handle, node, dev_node)		\
 	do {								\
-		const struct rte_memzone *mz;				\
-		char z_name[RTE_MEMZONE_NAMESIZE];			\
+		const struct rte_memzone *mz = NULL;			\
 		ENA_TOUCH(dmadev); ENA_TOUCH(dev_node);			\
-		snprintf(z_name, sizeof(z_name),			\
+		if (size > 0) {						\
+			char z_name[RTE_MEMZONE_NAMESIZE];		\
+			snprintf(z_name, sizeof(z_name),		\
 			 "ena_alloc_%d",				\
-			 rte_atomic32_add_return(&ena_alloc_cnt, 1));	\
-		mz = rte_memzone_reserve(z_name, size, node,		\
+			 rte_atomic32_add_return(&ena_alloc_cnt, 1));   \
+			mz = rte_memzone_reserve(z_name, size, node,	\
 				RTE_MEMZONE_IOVA_CONTIG);		\
-		mem_handle = mz;					\
+			mem_handle = mz;				\
+		}							\
 		if (mz == NULL) {					\
 			virt = NULL;					\
 			phys = 0;					\
-- 
2.20.1