From: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
Date: Tue, 14 Jun 2016 18:07:18 +0000 (+0100)
Subject: mem: fix possible integer overflow
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=d4ee3c61c06ceea054d269a44540e0db054a6db0;p=dpdk.git

mem: fix possible integer overflow

It is possible to get an integer overflow if we try to reserve a memzone
with len = 0 (meaning the maximum contiguous space available) and the
maximum available elem size is less than (MALLOC_ELEM_OVERHEAD + align).

Coverity issue: 107111

Fixes: fafcc11985a2 ("mem: rework memzone to be allocated by malloc")

Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
---

diff --git a/lib/librte_eal/common/eal_common_memzone.c b/lib/librte_eal/common/eal_common_memzone.c
index 452679ef9e..5d28341f7e 100644
--- a/lib/librte_eal/common/eal_common_memzone.c
+++ b/lib/librte_eal/common/eal_common_memzone.c
@@ -119,6 +119,9 @@ find_heap_max_free_elem(int *s, unsigned align)
 		}
 	}
 
+	if (len < MALLOC_ELEM_OVERHEAD + align)
+		return 0;
+
 	return len - MALLOC_ELEM_OVERHEAD - align;
 }
 
@@ -197,8 +200,13 @@ memzone_reserve_aligned_thread_unsafe(const char *name, size_t len,
 	if (len == 0) {
 		if (bound != 0)
 			requested_len = bound;
-		else
+		else {
 			requested_len = find_heap_max_free_elem(&socket_id, align);
+			if (requested_len == 0) {
+				rte_errno = ENOMEM;
+				return NULL;
+			}
+		}
 	}
 
 	if (socket_id == SOCKET_ID_ANY)