SUNRPC: Fix potential memory corruption

[ Upstream commit c2dc3e5fad13aca5d7bdf4bcb52b1a1d707c8555 ]

We really should not call rpc_wake_up_queued_task_set_status() with
xprt->snd_task as an argument unless we are certain that is actually an
rpc_task.

Fixes: 0445f92c5d53 ("SUNRPC: Fix disconnection races")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index d7ef5b97174ced5aa3c2b3956083e4d32cfeade9..3c6c4b1dbf1a4736801c997009e53fd7b4ebde46 100644 (file)
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -419,6 +419,7 @@ void                        xprt_unlock_connect(struct rpc_xprt *, void *);
 #define XPRT_CONGESTED         (9)
 #define XPRT_CWND_WAIT         (10)
 #define XPRT_WRITE_SPACE       (11)
+#define XPRT_SND_IS_COOKIE     (12)
 
 static inline void xprt_set_connected(struct rpc_xprt *xprt)
 {

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 639837b3a5d901756cd56d43299eba96b23a8d51..3653898f465ff4b8e6640c74f4d1d9aa292d78cd 100644 (file)
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -729,9 +729,9 @@ void xprt_force_disconnect(struct rpc_xprt *xprt)
        /* Try to schedule an autoclose RPC call */
        if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
                queue_work(xprtiod_workqueue, &xprt->task_cleanup);
-       else if (xprt->snd_task)
+       else if (xprt->snd_task && !test_bit(XPRT_SND_IS_COOKIE, &xprt->state))
                rpc_wake_up_queued_task_set_status(&xprt->pending,
-                               xprt->snd_task, -ENOTCONN);
+                                                  xprt->snd_task, -ENOTCONN);
        spin_unlock(&xprt->transport_lock);
 }
 EXPORT_SYMBOL_GPL(xprt_force_disconnect);
@@ -820,6 +820,7 @@ bool xprt_lock_connect(struct rpc_xprt *xprt,
                goto out;
        if (xprt->snd_task != task)
                goto out;
+       set_bit(XPRT_SND_IS_COOKIE, &xprt->state);
        xprt->snd_task = cookie;
        ret = true;
 out:
@@ -835,6 +836,7 @@ void xprt_unlock_connect(struct rpc_xprt *xprt, void *cookie)
        if (!test_bit(XPRT_LOCKED, &xprt->state))
                goto out;
        xprt->snd_task =NULL;
+       clear_bit(XPRT_SND_IS_COOKIE, &xprt->state);
        xprt->ops->release_xprt(xprt, NULL);
        xprt_schedule_autodisconnect(xprt);
 out: