Re: [PATCH v3] ceph: avoid putting the realm twice when decoding snaps fails

On Tue, Nov 8, 2022 at 2:46 PM xiubli@redhat.com wrote:

From: Xiubo Li xiubli@redhat.com

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@vger.kernel.org URL: https://tracker.ceph.com/issues/57686 Signed-off-by: Xiubo Li xiubli@redhat.com

---

fs/ceph/snap.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c index 9bceed2ebda3..f5b0fa1ff705 100644 --- a/fs/ceph/snap.c +++ b/fs/ceph/snap.c @@ -775,6 +775,7 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc,

    dout("%s deletion=%d\n", __func__, deletion);

more:

•   realm = NULL;
  

Nit: realm doesn't need to be initialized anymore, I would drop that.

Thanks,

Ilya