* [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs
@ 2026-06-09 23:22 Samuel Moelius
2026-06-11 14:43 ` Alexander Lobakin
2026-06-11 22:30 ` patchwork-bot+netdevbpf
0 siblings, 2 replies; 3+ messages in thread
From: Samuel Moelius @ 2026-06-09 23:22 UTC (permalink / raw)
To: Andrew Lunn
Cc: Samuel Moelius, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Wojciech Drewek, Marcin Szycik, Alexander Lobakin,
Simon Horman, open list:NETWORKING DRIVERS, open list
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
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs
2026-06-09 23:22 [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs Samuel Moelius
@ 2026-06-11 14:43 ` Alexander Lobakin
2026-06-11 22:30 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: Alexander Lobakin @ 2026-06-11 14:43 UTC (permalink / raw)
To: Samuel Moelius
Cc: Andrew Lunn, David S. Miller, Eric Dumazet, Jakub Kicinski,
Paolo Abeni, Wojciech Drewek, Marcin Szycik, Simon Horman,
open list:NETWORKING DRIVERS, open list
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
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs
2026-06-09 23:22 [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs Samuel Moelius
2026-06-11 14:43 ` Alexander Lobakin
@ 2026-06-11 22:30 ` patchwork-bot+netdevbpf
1 sibling, 0 replies; 3+ messages in thread
From: patchwork-bot+netdevbpf @ 2026-06-11 22:30 UTC (permalink / raw)
To: Samuel Moelius
Cc: andrew+netdev, davem, edumazet, kuba, pabeni, wojciech.drewek,
marcin.szycik, aleksander.lobakin, horms, netdev, linux-kernel
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!
--
Deet-doot-dot, I am a bot.
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2026-06-09 23:22 [PATCH net v2] net: pfcp: allocate per-cpu tstats for PFCP netdevs Samuel Moelius
2026-06-11 14:43 ` Alexander Lobakin
2026-06-11 22:30 ` patchwork-bot+netdevbpf
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