scsi: hpsa: Fix potential memory leak in hpsa_big_passthru_ioctl()

commit b812965 upstream.

Replace kmalloc() followed by copy_from_user() with memdup_user() to fix
a memory leak that occurs when copy_from_user(buff[sg_used],,) fails and
the 'cleanup1:' path does not free the memory for 'buff[sg_used]'. Using
memdup_user() avoids this by freeing the memory internally.

Since memdup_user() already allocates memory, use kzalloc() in the else
branch instead of manually zeroing 'buff[sg_used]' using memset(0).

Cc: stable@vger.kernel.org
Fixes: edd1636 ("[SCSI] hpsa: add driver for HP Smart Array controllers.")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: Don Brace <don.brace@microchip.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: toblux

drivers/scsi/hpsa.c

@@ -6528,18 +6528,21 @@ static int hpsa_big_passthru_ioctl(struct ctlr_info *h,
 	while (left) {
 		sz = (left > ioc->malloc_size) ? ioc->malloc_size : left;
 		buff_size[sg_used] = sz;
-		buff[sg_used] = kmalloc(sz, GFP_KERNEL);
-		if (buff[sg_used] == NULL) {
-			status = -ENOMEM;
-			goto cleanup1;
-		}
+
 		if (ioc->Request.Type.Direction & XFER_WRITE) {
-			if (copy_from_user(buff[sg_used], data_ptr, sz)) {
-				status = -EFAULT;
+			buff[sg_used] = memdup_user(data_ptr, sz);
+			if (IS_ERR(buff[sg_used])) {
+				status = PTR_ERR(buff[sg_used]);
 				goto cleanup1;
 			}
-		} else
-			memset(buff[sg_used], 0, sz);
+		} else {
+			buff[sg_used] = kzalloc(sz, GFP_KERNEL);
+			if (!buff[sg_used]) {
+				status = -ENOMEM;
+				goto cleanup1;
+			}
+		}
+
 		left -= sz;
 		data_ptr += sz;
 		sg_used++;