From: Myungho Jung <mhjungk@gmail.com>
To: Ilya Dryomov <idryomov@gmail.com>
Cc: "Yan, Zheng" <zyan@redhat.com>, Sage Weil <sage@redhat.com>,
"David S. Miller" <davem@davemloft.net>,
ceph-devel@vger.kernel.org, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH] libceph: protect pending flags in ceph_con_keepalive()
Date: Thu, 27 Dec 2018 11:08:45 -0800 [thread overview]
Message-ID: <20181227190842.GA19565@myunghoj-Precision-5530> (raw)
con_flag_test_and_set() sets CON_FLAG_KEEPALIVE_PENDING and
CON_FLAG_WRITE_PENDING flags without protection in ceph_con_keepalive().
It triggers WARN_ON() in clear_standby() if the flags are set after
con_fault() changes connection state to CON_STATE_STANDBY. Move
con_flag_test_and_set() to be called before releasing the lock and store
the condition to check after the critical section.
Reported-by: syzbot+acdeb633f6211ccdf886@syzkaller.appspotmail.com
Signed-off-by: Myungho Jung <mhjungk@gmail.com>
---
net/ceph/messenger.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 2f126eff275d..e15da22d4f37 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -3216,12 +3216,16 @@ void ceph_msg_revoke_incoming(struct ceph_msg *msg)
*/
void ceph_con_keepalive(struct ceph_connection *con)
{
+ bool pending;
+
dout("con_keepalive %p\n", con);
mutex_lock(&con->mutex);
clear_standby(con);
+ pending = (con_flag_test_and_set(con,
+ CON_FLAG_KEEPALIVE_PENDING) == 0 &&
+ con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0);
mutex_unlock(&con->mutex);
- if (con_flag_test_and_set(con, CON_FLAG_KEEPALIVE_PENDING) == 0 &&
- con_flag_test_and_set(con, CON_FLAG_WRITE_PENDING) == 0)
+ if (pending)
queue_con(con);
}
EXPORT_SYMBOL(ceph_con_keepalive);
--
2.17.1
next reply other threads:[~2018-12-27 19:08 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-27 19:08 Myungho Jung [this message]
2019-01-02 15:42 ` [PATCH] libceph: protect pending flags in ceph_con_keepalive() Ilya Dryomov
2019-01-03 3:50 ` Myungho Jung
2019-01-14 20:37 ` Ilya Dryomov
2019-01-15 6:55 ` Myungho Jung
2019-01-15 10:17 ` Ilya Dryomov
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