On 08/11/2022 17:56, Ilya Dryomov wrote:
On Tue, Nov 8, 2022 at 3:32 AM 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 Reviewed-by: Luís Henriques lhenriques@suse.de Signed-off-by: Xiubo Li xiubli@redhat.com
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.
Okay, will fix it.
Thanks!
- Xiubo
Thanks,
Ilya