[PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs

[PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs

[Samuel Moelius]

PFCP uses dev_get_tstats64() as its ndo_get_stats64 callback, but
pfcp_link_setup() does not request NETDEV_PCPU_STAT_TSTATS.  The net
core therefore leaves dev->tstats NULL for PFCP devices.

Creating a PFCP rtnetlink device can immediately ask the new netdev for
stats while building the RTM_NEWLINK notification.  That reaches
dev_get_tstats64() and dereferences the NULL dev->tstats pointer.

Set pcpu_stat_type to NETDEV_PCPU_STAT_TSTATS during PFCP link setup so
the net core allocates the storage expected by dev_get_tstats64().

Fixes: 76c8764ef36a ("pfcp: add PFCP module")
Assisted-by: Codex:gpt-5.5-cyber-preview
Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>
---
Changes in v2:
  - Added fixes tag

 drivers/net/pfcp.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/pfcp.c b/drivers/net/pfcp.c
index 28e6bc4a1f14..a6aa30ae0af7 100644
--- a/drivers/net/pfcp.c
+++ b/drivers/net/pfcp.c
@@ -148,6 +148,7 @@ static void pfcp_link_setup(struct net_device *dev)
 	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
 	dev->priv_flags |= IFF_NO_QUEUE;
 
+	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
 	netif_keep_dst(dev);
 }
 
-- 
2.43.0

Re: [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs

[Alexander Lobakin]

From: Samuel Moelius <sam.moelius@trailofbits.com>
Date: Tue,  9 Jun 2026 23:22:45 +0000

> PFCP uses dev_get_tstats64() as its ndo_get_stats64 callback, but
> pfcp_link_setup() does not request NETDEV_PCPU_STAT_TSTATS.  The net
> core therefore leaves dev->tstats NULL for PFCP devices.
> 
> Creating a PFCP rtnetlink device can immediately ask the new netdev for
> stats while building the RTM_NEWLINK notification.  That reaches
> dev_get_tstats64() and dereferences the NULL dev->tstats pointer.
> 
> Set pcpu_stat_type to NETDEV_PCPU_STAT_TSTATS during PFCP link setup so
> the net core allocates the storage expected by dev_get_tstats64().
> 
> Fixes: 76c8764ef36a ("pfcp: add PFCP module")
> Assisted-by: Codex:gpt-5.5-cyber-preview
> Signed-off-by: Samuel Moelius <sam.moelius@trailofbits.com>

Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>

> ---
> Changes in v2:
>   - Added fixes tag
> 
>  drivers/net/pfcp.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/pfcp.c b/drivers/net/pfcp.c
> index 28e6bc4a1f14..a6aa30ae0af7 100644
> --- a/drivers/net/pfcp.c
> +++ b/drivers/net/pfcp.c
> @@ -148,6 +148,7 @@ static void pfcp_link_setup(struct net_device *dev)
>  	dev->flags = IFF_POINTOPOINT | IFF_NOARP | IFF_MULTICAST;
>  	dev->priv_flags |= IFF_NO_QUEUE;
>  
> +	dev->pcpu_stat_type = NETDEV_PCPU_STAT_TSTATS;
>  	netif_keep_dst(dev);
>  }

Thanks,
Olek

Re: [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs

[patchwork-bot+netdevbpf]

Hello:

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

On Tue,  9 Jun 2026 23:22:45 +0000 you wrote:
> PFCP uses dev_get_tstats64() as its ndo_get_stats64 callback, but
> pfcp_link_setup() does not request NETDEV_PCPU_STAT_TSTATS.  The net
> core therefore leaves dev->tstats NULL for PFCP devices.
> 
> Creating a PFCP rtnetlink device can immediately ask the new netdev for
> stats while building the RTM_NEWLINK notification.  That reaches
> dev_get_tstats64() and dereferences the NULL dev->tstats pointer.
> 
> [...]

Here is the summary with links:
  - [net,v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs
    https://git.kernel.org/netdev/net/c/24041543da8c

You are awesome, thank you!
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