Re: [PATCH net] vsock: Use container_of() to get net namespace in sysctl handlers

[Stefano Garzarella <sgarzare@redhat.com>]

On Mon, Feb 23, 2026 at 06:32:18PM +0100, Greg Kroah-Hartman wrote:
>current->nsproxy is should not be accessed directly as syzbot has found
                   ^
nit: "is" can be removed

>that it could be NULL at times, causing crashes.  Fix up the af_vsock
>sysctl handlers to use container_of() to deal with the current net
>namespace instead of attempting to rely on current.
>
>This is the same type of change done in commit 7f5611cbc487 ("rds:
>sysctl: rds_tcp_{rcv,snd}buf: avoid using current->nsproxy")
>
>Cc: Stefano Garzarella <sgarzare@redhat.com>
>Cc: stable <stable@kernel.org>

I'm not sure this is stable material since these changes landed in the 
latest merge window (v7.0-rc1), but yeah, you know better than me, so 
there could be a reason.

If needed, maybe we can also add:

Fixes: eafb64f40ca4 ("vsock: add netns to vsock core")

>Assisted-by: gkh_clanker_2000
>Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>---
>
>Note, this is compile-tested only.  Some of my scripts found this when
>looking for places that are missing fixes that were applied to other
>parts of the kernel.  I think the af_vsock code uses namespaces, but as
>I don't know the network stack at all I figured I would let you all
>review it to tell me how wrong I got this change and all is fine with
>the original code.

Thanks! LGTM and tests are fine!

Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>

>
>thanks,
>
>greg k-h
>
> net/vmw_vsock/af_vsock.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
>diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
>index 9880756d9eff..f4062c6a1944 100644
>--- a/net/vmw_vsock/af_vsock.c
>+++ b/net/vmw_vsock/af_vsock.c
>@@ -2825,7 +2825,7 @@ static int vsock_net_mode_string(const struct ctl_table *table, int write,
> 	if (write)
> 		return -EPERM;
>
>-	net = current->nsproxy->net_ns;
>+	net = container_of(table->data, struct net, vsock.mode);
>
> 	return __vsock_net_mode_string(table, write, buffer, lenp, ppos,
> 				       vsock_net_mode(net), NULL);
>@@ -2838,7 +2838,7 @@ static int vsock_net_child_mode_string(const struct ctl_table *table, int write,
> 	struct net *net;
> 	int ret;
>
>-	net = current->nsproxy->net_ns;
>+	net = container_of(table->data, struct net, vsock.child_ns_mode);
>
> 	ret = __vsock_net_mode_string(table, write, buffer, lenp, ppos,
> 				      vsock_net_child_mode(net), &new_mode);
>-- 
>2.53.0
>