scsi: sg: add sg_remove_request in sg_write

commit 83c6f23 upstream.

If the __copy_from_user function failed we need to call sg_remove_request
in sg_write.

Link: https://lore.kernel.org/r/[email protected]
Acked-by: Douglas Gilbert <[email protected]>
Signed-off-by: Wu Bo <[email protected]>
Signed-off-by: Martin K. Petersen <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
[groeck: Backport to v5.4.y and older kernels]
Signed-off-by: Guenter Roeck <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Wu Bo

drivers/scsi/sg.c

@@ -695,8 +695,10 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos)
 	hp->flags = input_size;	/* structure abuse ... */
 	hp->pack_id = old_hdr.pack_id;
 	hp->usr_ptr = NULL;
-	if (__copy_from_user(cmnd, buf, cmd_size))
+	if (__copy_from_user(cmnd, buf, cmd_size)) {
+		sg_remove_request(sfp, srp);
 		return -EFAULT;
+	}
 	/*
 	 * SG_DXFER_TO_FROM_DEV is functionally equivalent to SG_DXFER_FROM_DEV,
 	 * but is is possible that the app intended SG_DXFER_TO_DEV, because there