Messages in this thread | | | Date | Mon, 7 Nov 2022 10:23:41 +0000 | From | Luís Henriques <> | Subject | Re: [PATCH] ceph: fix memory leak in mount error path when using test_dummy_encryption |
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On Mon, Nov 07, 2022 at 03:47:23PM +0800, Xiubo Li wrote: > > On 03/11/2022 23:36, 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@suse.de> > > --- > > fs/ceph/super.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/fs/ceph/super.c b/fs/ceph/super.c > > index 2224d44d21c0..6b9fd04b25cd 100644 > > --- a/fs/ceph/super.c > > +++ b/fs/ceph/super.c > > @@ -1362,6 +1362,7 @@ static int ceph_get_tree(struct fs_context *fc) > > ceph_mdsc_close_sessions(fsc->mdsc); > > deactivate_locked_super(sb); > > + fscrypt_free_dummy_policy(&fsc->fsc_dummy_enc_policy); > > Hi Luis, > > BTW, any reason the following code won't be triggered ? > > deactivate_locked_super(sb); > > --> fs->kill_sb(s); > > --> ceph_kill_sb() > > --> kill_anon_super() > > --> generic_shutdown_super() > > --> sop->put_super() > > --> ceph_put_super() > > --> ceph_fscrypt_free_dummy_policy() > > --> fscrypt_free_dummy_policy( >
Here's what I'm seeing here:
sys_mount->path_mount->do_new_mount->vfs_get_tree->ceph_get_tree
ceph_get_tree() fails due to ceph_real_mount() returning an error. My understanding is that that, since fc->root is never set, that code path will never be triggered. Does that make sense?
An easy way to reproduce is by running fstest ceph/005 with the 'test_dummy_encryption' option. (I'll probably need to send a patch to disable this test when this option is present.)
Cheers, -- Luís
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