Commit 5dd0dfd5 authored by Nick Child's avatar Nick Child Committed by Jakub Kicinski
Browse files

net: Catch invalid index in XPS mapping 



When setting the XPS value of a TX queue, warn the user once if the
index of the queue is greater than the number of allocated TX queues.

Previously, this scenario went uncaught. In the best case, it resulted
in unnecessary allocations. In the worst case, it resulted in
out-of-bounds memory references through calls to `netdev_get_tx_queue(
dev, index)`. Therefore, it is important to inform the user but not
worth returning an error and risk downing the netdevice.

Signed-off-by: default avatarNick Child <nnac123@linux.ibm.com>
Reviewed-by: default avatarPiotr Raczynski <piotr.raczynski@intel.com>
Link: https://lore.kernel.org/r/20230321150725.127229-1-nnac123@linux.ibm.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 5da12895

net/core/dev.c

+2 −0
Original line number Diff line number Diff line
@@ -2535,6 +2535,8 @@ int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask, 
	struct xps_map *map, *new_map;

	unsigned int nr_ids;



	WARN_ON_ONCE(index >= dev->num_tx_queues);



	if (dev->num_tc) {

		/* Do not allow XPS on subordinate device directly */

		num_tc = dev->num_tc;