2022-12-20 22:08:26

by Aaron Conole

[permalink] [raw]
Subject: [PATCH net] net: openvswitch: release vport resources on failure

A recent commit introducing upcall packet accounting failed to properly
release the vport object when the per-cpu stats struct couldn't be
allocated. This can cause dangling pointers to dp objects long after
they've been released.

Cc: Eelco Chaudron <[email protected]>
Cc: wangchuanlei <[email protected]>
Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
Reported-by: [email protected]
Signed-off-by: Aaron Conole <[email protected]>
---
net/openvswitch/datapath.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 932bcf766d63..6774baf9e212 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1854,7 +1854,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
if (!vport->upcall_stats) {
err = -ENOMEM;
- goto err_destroy_portids;
+ goto err_destroy_vport;
}

err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
@@ -1869,6 +1869,8 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
ovs_notify(&dp_datapath_genl_family, reply, info);
return 0;

+err_destroy_vport:
+ ovs_dp_detach_port(vport);
err_destroy_portids:
kfree(rcu_dereference_raw(dp->upcall_portids));
err_unlock_and_destroy_meters:
@@ -2316,7 +2318,7 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
if (!vport->upcall_stats) {
err = -ENOMEM;
- goto exit_unlock_free;
+ goto exit_unlock_free_vport;
}

err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
@@ -2336,6 +2338,8 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
ovs_notify(&dp_vport_genl_family, reply, info);
return 0;

+exit_unlock_free_vport:
+ ovs_dp_detach_port(vport);
exit_unlock_free:
ovs_unlock();
kfree_skb(reply);
--
2.31.1


2022-12-21 10:22:27

by Eelco Chaudron

[permalink] [raw]
Subject: Re: [PATCH net] net: openvswitch: release vport resources on failure



On 20 Dec 2022, at 22:27, Aaron Conole wrote:

> A recent commit introducing upcall packet accounting failed to properly
> release the vport object when the per-cpu stats struct couldn't be
> allocated. This can cause dangling pointers to dp objects long after
> they've been released.
>
> Cc: Eelco Chaudron <[email protected]>
> Cc: wangchuanlei <[email protected]>
> Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
> Reported-by: [email protected]
> Signed-off-by: Aaron Conole <[email protected]>
> ---

Thanks for finding and fixing this! The changes look good to me.

Acked-by: Eelco Chaudron <[email protected]>


> net/openvswitch/datapath.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index 932bcf766d63..6774baf9e212 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -1854,7 +1854,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
> vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
> if (!vport->upcall_stats) {
> err = -ENOMEM;
> - goto err_destroy_portids;
> + goto err_destroy_vport;
> }
>
> err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
> @@ -1869,6 +1869,8 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
> ovs_notify(&dp_datapath_genl_family, reply, info);
> return 0;
>
> +err_destroy_vport:
> + ovs_dp_detach_port(vport);
> err_destroy_portids:
> kfree(rcu_dereference_raw(dp->upcall_portids));
> err_unlock_and_destroy_meters:
> @@ -2316,7 +2318,7 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
> vport->upcall_stats = netdev_alloc_pcpu_stats(struct vport_upcall_stats_percpu);
> if (!vport->upcall_stats) {
> err = -ENOMEM;
> - goto exit_unlock_free;
> + goto exit_unlock_free_vport;
> }
>
> err = ovs_vport_cmd_fill_info(vport, reply, genl_info_net(info),
> @@ -2336,6 +2338,8 @@ static int ovs_vport_cmd_new(struct sk_buff *skb, struct genl_info *info)
> ovs_notify(&dp_vport_genl_family, reply, info);
> return 0;
>
> +exit_unlock_free_vport:
> + ovs_dp_detach_port(vport);
> exit_unlock_free:
> ovs_unlock();
> kfree_skb(reply);
> --
> 2.31.1

2022-12-21 10:33:51

by Michal Swiatkowski

[permalink] [raw]
Subject: Re: [PATCH net] net: openvswitch: release vport resources on failure

On Tue, Dec 20, 2022 at 04:27:17PM -0500, Aaron Conole wrote:
> A recent commit introducing upcall packet accounting failed to properly
> release the vport object when the per-cpu stats struct couldn't be
> allocated. This can cause dangling pointers to dp objects long after
> they've been released.
>
> Cc: Eelco Chaudron <[email protected]>
> Cc: wangchuanlei <[email protected]>
> Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
> Reported-by: [email protected]
> Signed-off-by: Aaron Conole <[email protected]>
> ---
Looks good, thanks

Reviewed-by: Michal Swiatkowski <[email protected]>
> --
> 2.31.1
>

2022-12-22 01:52:34

by patchwork-bot+netdevbpf

[permalink] [raw]
Subject: Re: [PATCH net] net: openvswitch: release vport resources on failure

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <[email protected]>:

On Tue, 20 Dec 2022 16:27:17 -0500 you wrote:
> A recent commit introducing upcall packet accounting failed to properly
> release the vport object when the per-cpu stats struct couldn't be
> allocated. This can cause dangling pointers to dp objects long after
> they've been released.
>
> Cc: Eelco Chaudron <[email protected]>
> Cc: wangchuanlei <[email protected]>
> Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
> Reported-by: [email protected]
> Signed-off-by: Aaron Conole <[email protected]>
>
> [...]

Here is the summary with links:
- [net] net: openvswitch: release vport resources on failure
https://git.kernel.org/netdev/net/c/95637d91fefd

You are awesome, thank you!
--
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