* [PATCH net-next] net: make sure we never create ifindex = 0
@ 2023-07-29 1:56 Jakub Kicinski
2023-07-30 13:32 ` Leon Romanovsky
0 siblings, 1 reply; 3+ messages in thread
From: Jakub Kicinski @ 2023-07-29 1:56 UTC (permalink / raw)
To: davem; +Cc: netdev, edumazet, pabeni, Jakub Kicinski, Stephen Hemminger, leon
Instead of allocating from 1 use proper xa_limit, to protect
ourselves from IDs wrapping back to 0.
Fixes: 759ab1edb56c ("net: store netdevs in an xarray")
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://lore.kernel.org/all/20230728162350.2a6d4979@hermes.local/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: leon@kernel.org
---
net/core/dev.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index b58674774a57..2312ca67b95e 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -9587,7 +9587,8 @@ static int dev_index_reserve(struct net *net, u32 ifindex)
if (!ifindex)
err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
- xa_limit_31b, &net->ifindex, GFP_KERNEL);
+ XA_LIMIT(1, INT_MAX), &net->ifindex,
+ GFP_KERNEL);
else
err = xa_insert(&net->dev_by_index, ifindex, NULL, GFP_KERNEL);
if (err < 0)
@@ -11271,7 +11272,6 @@ 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);
RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
--
2.41.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH net-next] net: make sure we never create ifindex = 0
2023-07-29 1:56 [PATCH net-next] net: make sure we never create ifindex = 0 Jakub Kicinski
@ 2023-07-30 13:32 ` Leon Romanovsky
2023-07-31 16:03 ` Jakub Kicinski
0 siblings, 1 reply; 3+ messages in thread
From: Leon Romanovsky @ 2023-07-30 13:32 UTC (permalink / raw)
To: Jakub Kicinski; +Cc: davem, netdev, edumazet, pabeni, Stephen Hemminger
On Fri, Jul 28, 2023 at 06:56:23PM -0700, Jakub Kicinski wrote:
> Instead of allocating from 1 use proper xa_limit, to protect
> ourselves from IDs wrapping back to 0.
>
> Fixes: 759ab1edb56c ("net: store netdevs in an xarray")
> Reported-by: Stephen Hemminger <stephen@networkplumber.org>
> Link: https://lore.kernel.org/all/20230728162350.2a6d4979@hermes.local/
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
> CC: leon@kernel.org
> ---
> net/core/dev.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/net/core/dev.c b/net/core/dev.c
> index b58674774a57..2312ca67b95e 100644
> --- a/net/core/dev.c
> +++ b/net/core/dev.c
> @@ -9587,7 +9587,8 @@ static int dev_index_reserve(struct net *net, u32 ifindex)
>
> if (!ifindex)
> err = xa_alloc_cyclic(&net->dev_by_index, &ifindex, NULL,
> - xa_limit_31b, &net->ifindex, GFP_KERNEL);
> + XA_LIMIT(1, INT_MAX), &net->ifindex,
> + GFP_KERNEL);
> else
> err = xa_insert(&net->dev_by_index, ifindex, NULL, GFP_KERNEL);
> if (err < 0)
> @@ -11271,7 +11272,6 @@ 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);
You don't need to change xa_limit_31b, just change XA_FLAGS_ALLOC to be XA_FLAGS_ALLOC1
and allocations will start from 1.
Thanks
>
> RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
> --
> 2.41.0
>
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH net-next] net: make sure we never create ifindex = 0
2023-07-30 13:32 ` Leon Romanovsky
@ 2023-07-31 16:03 ` Jakub Kicinski
0 siblings, 0 replies; 3+ messages in thread
From: Jakub Kicinski @ 2023-07-31 16:03 UTC (permalink / raw)
To: Leon Romanovsky; +Cc: davem, netdev, edumazet, pabeni, Stephen Hemminger
On Sun, 30 Jul 2023 16:32:19 +0300 Leon Romanovsky wrote:
> > @@ -11271,7 +11272,6 @@ 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);
>
> You don't need to change xa_limit_31b, just change XA_FLAGS_ALLOC to be XA_FLAGS_ALLOC1
> and allocations will start from 1.
Because obviously there is a magic flag for this...
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2023-07-31 16:03 UTC | newest]
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2023-07-29 1:56 [PATCH net-next] net: make sure we never create ifindex = 0 Jakub Kicinski
2023-07-30 13:32 ` Leon Romanovsky
2023-07-31 16:03 ` Jakub Kicinski
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