| Message ID | 20221108023141.64972-1-xiubli@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] ceph: avoid putting the realm twice when decoding snaps fails | expand |
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. Thanks, Ilya
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 >
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; + if (p < e) goto more;