Re: [PATCH v2] ceph: fix memory leak in mount error path when using test_dummy_encryption

[Luís Henriques]

On Wed, Nov 09, 2022 at 05:57:41PM +0800, Xiubo Li wrote:
> Hi Luis,
> 
> Please check https://github.com/ceph/ceph-client/commit/205efda80b6759a741dde209a7158a5bbf044d23#diff-eb62c69f842ed95a7d047262a62946b07eda52f2ea49ae33c39ea13754dfc291.

Ugh! That's quite confusing :-)

I did a 'git fetch' and looked into commit 205efda80b67 ("ceph: implement
-o test_dummy_encryption mount option") instead, and compared it with it's
version in the wip-fscrypt branch.  It looks good to me: the only
difference I see is my fix (adding the 'ceph_fscrypt_free_dummy_policy'
call to 'ceph_real_mount').  Thanks!

Cheers,
--
Luís

> 
> Currently I only applied it into the 'testing' branch.
> 
> Thanks!
> 
> - Xiubo
> 
> 
> On 09/11/2022 17:33, Luís Henriques wrote:
> > On Wed, Nov 09, 2022 at 11:08:49AM +0800, Xiubo Li wrote:
> > > On 08/11/2022 22:34, Luís Henriques wrote:
> > > > Because ceph_init_fs_context() will never be invoced in case we get a
> > > > mount error, destroy_mount_options() won't be releasing fscrypt resources
> > > > with fscrypt_free_dummy_policy().  This will result in a memory leak.  Add
> > > > an invocation to this function in the mount error path.
> > > > 
> > > > Signed-off-by: Luís Henriques <lhenriques@xxxxxxx>
> > > > ---
> > > > * Changes since v1:
> > > > 
> > > > As suggested by Xiubo, moved fscrypt free from ceph_get_tree() to
> > > > ceph_real_mount().
> > > > 
> > > > (Also used 'git format-patch' with '--base' so that the bots know what to
> > > > (not) do with this patch.)
> > > > 
> > > >    fs/ceph/super.c | 1 +
> > > >    1 file changed, 1 insertion(+)
> > > > 
> > > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c
> > > > index 2224d44d21c0..f10a076f47e5 100644
> > > > --- a/fs/ceph/super.c
> > > > +++ b/fs/ceph/super.c
> > > > @@ -1196,6 +1196,7 @@ static struct dentry *ceph_real_mount(struct ceph_fs_client *fsc,
> > > >    out:
> > > >    	mutex_unlock(&fsc->client->mount_mutex);
> > > > +	ceph_fscrypt_free_dummy_policy(fsc);
> > > >    	return ERR_PTR(err);
> > > >    }
> > > > 
> > > > base-commit: 8b9ee21dfceadd4cc35a87bbe7f0ad547cffa1be
> > > > prerequisite-patch-id: 34ba9e6b37b68668d261ddbda7858ee6f83c82fa
> > > > prerequisite-patch-id: 87f1b323c29ab8d0a6d012d30fdc39bc49179624
> > > > prerequisite-patch-id: c94f448ef026375b10748457a3aa46070aa7046e
> > > > 
> > > LGTM.
> > > 
> > > Thanks Luis.
> > > 
> > > Could I fold this into the previous commit ?
> > Yes, sure.  I'm fine with that.
> > 
> > Cheers,
> > --
> > Luís
> > 
>