Re: [PATCH v2] tty: rfcomm: prefer struct_size over open coded arithmetic

From: Jiri Slaby
Date: Mon May 13 2024 - 01:07:50 EST


On 12. 05. 24, 13:17, Erick Archer wrote:
This is an effort to get rid of all multiplications from allocation
functions in order to prevent integer overflows [1][2].

As the "dl" variable is a pointer to "struct rfcomm_dev_list_req" and
this structure ends in a flexible array:
..
--- a/include/net/bluetooth/rfcomm.h
+++ b/include/net/bluetooth/rfcomm.h
..
@@ -528,12 +527,12 @@ static int rfcomm_get_dev_list(void __user *arg)
list_for_each_entry(dev, &rfcomm_dev_list, list) {
if (!tty_port_get(&dev->port))
continue;
- (di + n)->id = dev->id;
- (di + n)->flags = dev->flags;
- (di + n)->state = dev->dlc->state;
- (di + n)->channel = dev->channel;
- bacpy(&(di + n)->src, &dev->src);
- bacpy(&(di + n)->dst, &dev->dst);
+ di[n].id = dev->id;
+ di[n].flags = dev->flags;
+ di[n].state = dev->dlc->state;
+ di[n].channel = dev->channel;
+ bacpy(&di[n].src, &dev->src);
+ bacpy(&di[n].dst, &dev->dst);

This does not relate much to "prefer struct_size over open coded arithmetic". It should have been in a separate patch.

Other than that, LGTM.

thanks,
--
js
suse labs