On Tue, Nov 8, 2022 at 3:32 AM <xiubli@xxxxxxxxxx> wrote: > > From: Xiubo Li <xiubli@xxxxxxxxxx> > > When decoding the snaps fails it maybe leaving the 'first_realm' > and 'realm' pointing to the same snaprealm memory. And then it'll > put it twice and could cause random use-after-free, BUG_ON, etc > issues. > > Cc: stable@xxxxxxxxxxxxxxx > URL: https://tracker.ceph.com/issues/57686 > Reviewed-by: Luís Henriques <lhenriques@xxxxxxx> > Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx> > --- > fs/ceph/snap.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c > index 9bceed2ebda3..77b948846d4d 100644 > --- a/fs/ceph/snap.c > +++ b/fs/ceph/snap.c > @@ -854,6 +854,8 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc, > else > ceph_put_snap_realm(mdsc, realm); > > + realm = NULL; Hi Xiubo, Nit: I think it would be better to clear realm in the part of the function that actually needs it to be cleared -- otherwise this assignment can be easily lost in refactoring. dout("%s deletion=%d\n", __func__, deletion); more: realm = NULL; rebuild_snapcs = 0; And then realm wouldn't need to be initialized. Thanks, Ilya
