What we need is only "pack_id", so do not create a heap object or copy
the whole object in. The fix efficiently copies "pack_id" only and
also avoids double-fetch.
Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
---
drivers/scsi/sg.c | 12 ++----------
1 file changed, 2 insertions(+), 10 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index c6ad00703c5b..13662c41058a 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -446,16 +446,8 @@ sg_read(struct file *filp, char __user *buf, size_t count, loff_t * ppos)
}
if (old_hdr->reply_len < 0) {
if (count >= SZ_SG_IO_HDR) {
- sg_io_hdr_t *new_hdr;
- new_hdr = kmalloc(SZ_SG_IO_HDR, GFP_KERNEL);
- if (!new_hdr) {
- retval = -ENOMEM;
- goto free_old_hdr;
- }
- retval =__copy_from_user
- (new_hdr, buf, SZ_SG_IO_HDR);
- req_pack_id = new_hdr->pack_id;
- kfree(new_hdr);
+ retval = get_user(req_pack_id,
+ &((sg_io_hdr_t *)buf)->pack_id);
if (retval) {
retval = -EFAULT;
goto free_old_hdr;
--
2.17.1
