On 09/11/2022 18:03, Ilya Dryomov wrote:
On Wed, Nov 9, 2022 at 4:00 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
Signed-off-by: Xiubo Li <xiubli@xxxxxxxxxx>
---
Changed in V4:
- remove initilizing of 'realm'.
fs/ceph/snap.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
index 9bceed2ebda3..c1c452afa84d 100644
--- a/fs/ceph/snap.c
+++ b/fs/ceph/snap.c
@@ -764,7 +764,7 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc,
struct ceph_mds_snap_realm *ri; /* encoded */
__le64 *snaps; /* encoded */
__le64 *prior_parent_snaps; /* encoded */
- struct ceph_snap_realm *realm = NULL;
+ struct ceph_snap_realm *realm;
struct ceph_snap_realm *first_realm = NULL;
struct ceph_snap_realm *realm_to_rebuild = NULL;
int rebuild_snapcs;
@@ -775,6 +775,7 @@ int ceph_update_snap_trace(struct ceph_mds_client *mdsc,
dout("%s deletion=%d\n", __func__, deletion);
more:
+ realm = NULL;
rebuild_snapcs = 0;
ceph_decode_need(&p, e, sizeof(*ri), bad);
ri = p;
--
2.31.1
Reviewed-by: Ilya Dryomov <idryomov@xxxxxxxxx>
Thanks very much Ilya!
Thanks,
Ilya
