The function ceph_monc_handle_map calls kfree(old) to free the old
monitor map, old points to monc->monmap. However, after that, it reads
monc->monmap->epoch and passes it to __ceph_monc_got_map. This result in
a use-after-free bug. The patch moves the free operation after the call
to __ceph_monc_got_map.
Fixes: 82dcabad750("libceph: revamp subs code, switch to SUBSCRIBE2
protocol")
Signed-off-by: Pan Bian <bianpan2016@xxxxxxx>
---
net/ceph/mon_client.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index 18deb3d..05ef5aa 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -478,9 +478,10 @@ static void ceph_monc_handle_map(struct ceph_mon_client *monc,
}
client->monc.monmap = monmap;
- kfree(old);
__ceph_monc_got_map(monc, CEPH_SUB_MONMAP, monc->monmap->epoch);
+ kfree(old);
+
client->have_fsid = true;
out:
--
2.7.4
