[PATCH v2] scsi: be2iscsi: fix potential NULL pointer dereference

From: Dmitry Voytik
Date: Wed Jan 16 2019 - 17:48:18 EST


Fix potential NULL pointer dereference wich might happen in
beiscsi_alloc_mem(). If kmalloc_array() fails and mem_descr->mem_array
is set to NULL, then its dereferencing happens when passing
mem_descr->mem_array[] to dma_free_coherent().

Signed-off-by: Dmitry Voytik <voytikd@xxxxxxxxx>
---

Changes since v1:
- prevent double free by setting mem_arr_orig to NULL

drivers/scsi/be2iscsi/be_main.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/be2iscsi/be_main.c b/drivers/scsi/be2iscsi/be_main.c
index 74e260027c7d..7b8c80318c38 100644
--- a/drivers/scsi/be2iscsi/be_main.c
+++ b/drivers/scsi/be2iscsi/be_main.c
@@ -2527,8 +2527,11 @@ static int beiscsi_alloc_mem(struct beiscsi_hba *phba)
mem_descr->size_in_bytes = phba->mem_req[i];
mem_descr->mem_array = kmalloc_array(j, sizeof(*mem_arr),
GFP_KERNEL);
- if (!mem_descr->mem_array)
+ if (!mem_descr->mem_array) {
+ mem_descr->mem_array = mem_arr_orig;
+ mem_arr_orig = NULL;
goto free_mem;
+ }

memcpy(mem_descr->mem_array, mem_arr_orig,
sizeof(struct mem_array) * j);
--
2.20.1