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From: Andrei Vagin <avagin@gmail.com>
Date: Tue, 11 Sep 2018 13:27:03 -0700
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Subject: Re: [dhowells/mount-api] general protection fault in mqueue_get_tree
To: David Howells <dhowells@redhat.com>
Cc: linux-fsdevel <linux-fsdevel@vger.kernel.org>
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On Tue, Sep 11, 2018 at 1:21 PM David Howells <dhowells@redhat.com> wrote:
>
> Andrei Vagin <avagin@gmail.com> wrote:
>
> > +       ns->mq_mnt = NULL;
>
> Should I instead be allocating the namespace with kzalloc()?

The ipc_namespace structure is big, so I am not sure about kzalloc().
ns->mq_mnt can be initialized in mq_init_ns, it looks better than my
previous patch.

diff --git a/ipc/mqueue.c b/ipc/mqueue.c
index ab1fe762baa8..e05147b5ea39 100644
--- a/ipc/mqueue.c
+++ b/ipc/mqueue.c
@@ -1618,6 +1618,7 @@ int mq_init_ns(struct ipc_namespace *ns)
        ns->mq_msg_default   = DFLT_MSG;
        ns->mq_msgsize_default  = DFLT_MSGSIZE;

+       ns->mq_mnt = NULL;
        m = mq_create_mount(ns);
        if (IS_ERR(m))
                return PTR_ERR(m);

>
> David