[dpdk-dev] [PATCH] ivshmem: fix segmentation fault in corner case

[Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>]

Depending on the configured segments it is possible to hit a
segmentation fault as a result of decrementing an unsigned index with
value 0.

To avoid it, exit the loop if the index has value 0.

Signed-off-by: Sergio Gonzalez Monroy <sergio.gonzalez.monroy@intel.com>
---
 lib/librte_ivshmem/rte_ivshmem.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/librte_ivshmem/rte_ivshmem.c b/lib/librte_ivshmem/rte_ivshmem.c
index 7ca55ed..9621906 100644
--- a/lib/librte_ivshmem/rte_ivshmem.c
+++ b/lib/librte_ivshmem/rte_ivshmem.c
@@ -377,6 +377,8 @@ build_config(struct rte_ivshmem_metadata * metadata)
 			for (j = biggest_idx - 1; j >= i; j--) {
 				memcpy(&pages[j+1], &pages[j], sizeof(struct rte_memseg));
 				memset(&pages[j], 0, sizeof(struct rte_memseg));
+				if (j == 0)
+					break;
 			}
 
 			/* put old biggest segment to its new place */
-- 
1.9.3