Re: [PATCH] NFSv4: Fix a memory leak bug
From: Wenwen Wang
Date: Tue Aug 20 2019 - 14:54:30 EST
On Tue, Aug 20, 2019 at 9:41 AM Schumaker, Anna
<Anna.Schumaker@xxxxxxxxxx> wrote:
>
> Hi Wenwen,
>
> On Tue, 2019-08-20 at 02:54 -0500, Wenwen Wang wrote:
> > In nfs4_try_migration(), if nfs4_begin_drain_session() fails, the
> > previously allocated 'page' and 'locations' are not deallocated,
> > leading to
> > memory leaks. To fix this issue, free 'page' and 'locations' before
> > returning the error.
> >
> > Signed-off-by: Wenwen Wang <wenwen@xxxxxxxxxx>
> > ---
> > fs/nfs/nfs4state.c | 6 +++++-
> > 1 file changed, 5 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
> > index cad4e06..37823dc 100644
> > --- a/fs/nfs/nfs4state.c
> > +++ b/fs/nfs/nfs4state.c
> > @@ -2095,8 +2095,12 @@ static int nfs4_try_migration(struct
> > nfs_server *server, const struct cred *cred
> > }
> >
> > status = nfs4_begin_drain_session(clp);
> > - if (status != 0)
> > + if (status != 0) {
> > + if (page != NULL)
> > + __free_page(page);
> > + kfree(locations);
> > return status;
>
> Thanks for the suggestion! I think a better option would be to switch
> the "return status" into a "goto out" so we can keep all our cleanup
> code in a single place in case we ever need to change it in the future.
>
> What do you think?
Thanks for your comments! I will rework the patch.
Wenwen
> Anna
>
> > + }
> >
> > status = nfs4_replace_transport(server, locations);
> > if (status != 0) {
> > --
> > 2.7.4
> >