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SubjectRe: [PATCH v3 0/3] auth_gss: netns refcount leaks when use-gss-proxy==1
I lost track, what happened to these patches?

--b.

On Wed, Jun 12, 2019 at 08:09:27PM +0800, Wenbin Zeng wrote:
> This patch series fixes an auth_gss bug that results in netns refcount
> leaks when use-gss-proxy is set to 1.
>
> The problem was found in privileged docker containers with gssproxy service
> enabled and /proc/net/rpc/use-gss-proxy set to 1, the corresponding
> struct net->count ends up at 2 after container gets killed, the consequence
> is that the struct net cannot be freed.
>
> It turns out that write_gssp() called gssp_rpc_create() to create a rpc
> client, this increases net->count by 2; rpcsec_gss_exit_net() is supposed
> to decrease net->count but it never gets called because its call-path is:
> net->count==0 -> cleanup_net -> ops_exit_list -> rpcsec_gss_exit_net
> Before rpcsec_gss_exit_net() gets called, net->count cannot reach 0, this
> is a deadlock situation.
>
> To fix the problem, we must break the deadlock, rpcsec_gss_exit_net()
> should move out of the put() path and find another chance to get called,
> I think nsfs_evict() is a good place to go, when netns inode gets evicted
> we call rpcsec_gss_exit_net() to free the rpc client, this requires a new
> callback i.e. evict to be added in struct proc_ns_operations, and add
> netns_evict() as one of netns_operations as well.
>
> v1->v2:
> * in nsfs_evict(), move ->evict() in front of ->put()
> v2->v3:
> * rpcsec_gss_evict_net() directly call gss_svc_shutdown_net() regardless
> if gssp_clnt is null, this is exactly same to what rpcsec_gss_exit_net()
> previously did
>
> Wenbin Zeng (3):
> nsfs: add evict callback into struct proc_ns_operations
> netns: add netns_evict into netns_operations
> auth_gss: fix deadlock that blocks rpcsec_gss_exit_net when
> use-gss-proxy==1
>
> fs/nsfs.c | 2 ++
> include/linux/proc_ns.h | 1 +
> include/net/net_namespace.h | 1 +
> net/core/net_namespace.c | 12 ++++++++++++
> net/sunrpc/auth_gss/auth_gss.c | 4 ++--
> 5 files changed, 18 insertions(+), 2 deletions(-)
>
> --
> 1.8.3.1

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