From ceaac91dcd065db781d1ed5dfaef0686b8ec44dc Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Mon, 31 Jul 2023 10:11:58 -0700 Subject: [PATCH] net: make sure we never create ifindex = 0 Instead of allocating from 1 use proper xa_init flag, to protect ourselves from IDs wrapping back to 0. Fixes: 759ab1edb56c ("net: store netdevs in an xarray") Reported-by: Stephen Hemminger Link: https://lore.kernel.org/all/20230728162350.2a6d4979@hermes.local/ Reviewed-by: Leon Romanovsky Link: https://lore.kernel.org/r/20230731171159.988962-1-kuba@kernel.org Signed-off-by: Jakub Kicinski --- net/core/dev.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/net/core/dev.c b/net/core/dev.c index b58674774a57b..10e5a036c706a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11271,8 +11271,7 @@ static int __net_init netdev_init(struct net *net) if (net->dev_index_head == NULL) goto err_idx; - net->ifindex = 1; - xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC); + xa_init_flags(&net->dev_by_index, XA_FLAGS_ALLOC1); RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain); -- 2.30.2