Messages in this thread | | | Subject | Re: Re: [PATCH v3 0/3] auth_gss: netns refcount leaks when use-gss-proxy==1 | From | "wanghai (M)" <> | Date | Sat, 28 Aug 2021 19:26:30 +0800 |
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在 2019/8/2 3:53, J. Bruce Fields 写道: > 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 These patchsets don't seem to merge into the mainline, are there any other patches that fix this bug?
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