[PATCH v4 3/5] scsi: ufs: fix potential access NULL pointer while memcpy

From: Bean Huo
Date: Sun May 31 2020 - 11:09:10 EST


From: Bean Huo <beanhuo@xxxxxxxxxx>

If param_offset is not 0, the memcpy length shouldn't be the
true descriptor length.

Fixes: a4b0e8a4e92b ("scsi: ufs: Factor out ufshcd_read_desc_param")
Signed-off-by: Bean Huo <beanhuo@xxxxxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index f7e8bfefe3d4..bc52a0e89cd3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -3211,7 +3211,7 @@ int ufshcd_read_desc_param(struct ufs_hba *hba,

/* Check wherher we will not copy more data, than available */
if (is_kmalloc && param_size > buff_len)
- param_size = buff_len;
+ param_size = buff_len - param_offset;

if (is_kmalloc)
memcpy(param_read_buf, &desc_buf[param_offset], param_size);
--
2.17.1