[PATCH net] net: llc: make empty have static storage duration

[PATCH net] net: llc: make empty have static storage duration

[Wentao Guan]

Make empty have static storage duration (like net/sysctl_net.c does) to
avoid a potential use-after-return and keep consistent with
__register_sysctl_table @table 'should not be free'd after registration'.

Fixes: 73dbd8cf7947 ("net: Remove ctl_table sentinel elements from several networking subsystems")
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
---
 net/llc/sysctl_net_llc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/llc/sysctl_net_llc.c b/net/llc/sysctl_net_llc.c
index c8d88e2508fce..15f1e5d88f208 100644
--- a/net/llc/sysctl_net_llc.c
+++ b/net/llc/sysctl_net_llc.c
@@ -47,7 +47,7 @@ static struct ctl_table_header *llc_station_header;
 
 int __init llc_sysctl_init(void)
 {
-	struct ctl_table empty[1] = {};
+	static struct ctl_table empty[1] = {};
 	llc2_timeout_header = register_net_sysctl(&init_net, "net/llc/llc2/timeout", llc2_timeout_table);
 	llc_station_header = register_net_sysctl_sz(&init_net, "net/llc/station", empty, 0);
 
-- 
2.30.2

Re: [PATCH net] net: llc: make empty have static storage duration

[Simon Horman]

On Tue, Jun 16, 2026 at 02:40:53PM +0800, Wentao Guan wrote:
> Make empty have static storage duration (like net/sysctl_net.c does) to
> avoid a potential use-after-return and keep consistent with
> __register_sysctl_table @table 'should not be free'd after registration'.
> 
> Fixes: 73dbd8cf7947 ("net: Remove ctl_table sentinel elements from several networking subsystems")
> Signed-off-by: Wentao Guan <guanwentao@uniontech.com>

Reviewed-by: Simon Horman <horms@kernel.org>

Re: [PATCH net] net: llc: make empty have static storage duration

[Jakub Kicinski]

On Tue, 16 Jun 2026 14:40:53 +0800 Wentao Guan wrote:
> Make empty have static storage duration (like net/sysctl_net.c does) to
> avoid a potential use-after-return and keep consistent with
> __register_sysctl_table @table 'should not be free'd after registration'.
> 
> Fixes: 73dbd8cf7947 ("net: Remove ctl_table sentinel elements from several networking subsystems")
> Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
> ---
>  net/llc/sysctl_net_llc.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/llc/sysctl_net_llc.c b/net/llc/sysctl_net_llc.c
> index c8d88e2508fce..15f1e5d88f208 100644
> --- a/net/llc/sysctl_net_llc.c
> +++ b/net/llc/sysctl_net_llc.c
> @@ -47,7 +47,7 @@ static struct ctl_table_header *llc_station_header;
>  
>  int __init llc_sysctl_init(void)
>  {
> -	struct ctl_table empty[1] = {};
> +	static struct ctl_table empty[1] = {};
>  	llc2_timeout_header = register_net_sysctl(&init_net, "net/llc/llc2/timeout", llc2_timeout_table);
>  	llc_station_header = register_net_sysctl_sz(&init_net, "net/llc/station", empty, 0);

I will apply this but it's not a bug.

The size is 0, even tho the pointer is stored there can be no access.

Re: [PATCH net] net: llc: make empty have static storage duration

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Tue, 16 Jun 2026 14:40:53 +0800 you wrote:
> Make empty have static storage duration (like net/sysctl_net.c does) to
> avoid a potential use-after-return and keep consistent with
> __register_sysctl_table @table 'should not be free'd after registration'.
> 
> Fixes: 73dbd8cf7947 ("net: Remove ctl_table sentinel elements from several networking subsystems")
> Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
> 
> [...]

Here is the summary with links:
  - [net] net: llc: make empty have static storage duration
    https://git.kernel.org/netdev/net/c/d31deeab707b

You are awesome, thank you!
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