From: Pan Bian <bianpan2016@163.com>
To: Ilya Dryomov <idryomov@gmail.com>, "Yan, Zheng" <zyan@redhat.com>,
Sage Weil <sage@redhat.com>,
"David S. Miller" <davem@davemloft.net>
Cc: ceph-devel@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, Pan Bian <bianpan2016@163.com>
Subject: [PATCH] libceph: fix use after free
Date: Tue, 27 Nov 2018 15:02:07 +0800 [thread overview]
Message-ID: <1543302127-14435-1-git-send-email-bianpan2016@163.com> (raw)
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@163.com>
---
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
next reply other threads:[~2018-11-27 7:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-27 7:02 Pan Bian [this message]
2018-11-27 8:47 ` [PATCH] libceph: fix use after free Sergei Shtylyov
2018-11-27 9:09 ` PanBian
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