Commit 51884d15 authored by Xiubo Li's avatar Xiubo Li Committed by Ilya Dryomov
Browse files

ceph: avoid putting the realm twice when decoding snaps fails 

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
Link: https://tracker.ceph.com/issues/57686


Signed-off-by: default avatarXiubo Li <xiubli@redhat.com>
Reviewed-by: default avatarIlya Dryomov <idryomov@gmail.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent f86a4866

fs/ceph/snap.c

+2 −1
Original line number Diff line number Diff line
@@ -763,7 +763,7 @@ 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;
@@ -774,6 +774,7 @@ 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;