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

[Stefano Garzarella]

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 <sgarz...@redhat.com>
Cc: stable <sta...@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 <gre...@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 <sgarz...@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