On 08/11/2022 17:56, Ilya Dryomov wrote:
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.
Okay, will fix it.
Thanks!
- Xiubo
Thanks,
Ilya
