Since the xarray changes we mix returning valid ifindex and negative
errno in a single int returned from dev_index_reserve(). This depends
on the fact that ifindexes can't be negative. Otherwise we may insert
into the xarray and return a very large negative value. This in turn
may break ERR_PTR().
OvS is susceptible to this problem and lacking validation (fix posted
separately for net).
Reject negative ifindex explicitly. Add a warning because the input
validation is better handled by the caller.
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Link: https://lore.kernel.org/r/20230814205627.2914583-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
{
int err;
+ if (ifindex > INT_MAX) {
+ DEBUG_NET_WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
if (!ifindex)
err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
xa_limit_31b, &net->ifindex, GFP_KERNEL);