• Eric W. Biederman's avatar
    NFS: Fix /proc/fs/nfsfs/servers and /proc/fs/nfsfs/volumes · 65b38851
    Eric W. Biederman authored
    The usage of pid_ns->child_reaper->nsproxy->net_ns in
    nfs_server_list_open and nfs_client_list_open is not safe.
    
    /proc for a pid namespace can remain mounted after the all of the
    process in that pid namespace have exited.  There are also times
    before the initial process in a pid namespace has started or after the
    initial process in a pid namespace has exited where
    pid_ns->child_reaper can be NULL or stale.  Making the idiom
    pid_ns->child_reaper->nsproxy a double whammy of problems.
    
    Luckily all that needs to happen is to move /proc/fs/nfsfs/servers and
    /proc/fs/nfsfs/volumes under /proc/net to /proc/net/nfsfs/servers and
    /proc/net/nfsfs/volumes and add a symlink from the original location,
    and to use seq_open_net as it has been designed.
    
    Cc: stable@vger.kernel.org
    Cc: Trond Myklebust <trond.myklebust@primarydata.com>
    Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>
    Signed-off-by: default avatar"Eric W. Biederman" <ebiederm@xmission.com>
    65b38851
internal.h 20.5 KB