Commit 95820a36 authored Oct 13, 2008 by Tejun Heo Committed by Eric Van Hensbergen Oct 17, 2008

9p: drop broken unused error path from p9_conn_create()



Post p9_fd_poll() error path which checks m->poll_waddr[i] for PTR_ERR
value has the following problems.

* It's completely unused.  Error value is set iff NULL @wait_address
  has been specified to p9_pollwait() which is guaranteed not to
  happen.

* It dereferences @m after deallocating it (introduced by 571ffeaf and
  spotted by Raja R Harinath.

* It returned the wrong value on error.  It should return
  poll_waddr[i] but it returnes poll_waddr (introduced by 571ffeaf).

* p9_mux_poll_stop() doesn't handle PTR_ERR value.  It will try to
  operate on the PTR_ERR value as if it's a normal pointer and cause
  oops.

As the error path is bogus in the first place, there's no reason to
hold onto it.  Kill it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Raja R Harinath <harinath@hurrynot.org>

parent 91b8534f

net/9p/trans_fd.c

+1 −16

Original line number	Diff line number	Diff line
		@@ -540,12 +540,6 @@ p9_pollwait(struct file filp, wait_queue_head_t wait_address, poll_table *p)
		return;
		}

		if (!wait_address) {
		P9_DPRINTK(P9_DEBUG_ERROR, "no wait_address\n");
		pwait->wait_addr = ERR_PTR(-EIO);
		return;
		}

		pwait->conn = m;
		pwait->wait_addr = wait_address;
		init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
		@@ -561,7 +555,7 @@ p9_pollwait(struct file filp, wait_queue_head_t wait_address, poll_table *p)

		static struct p9_conn p9_conn_create(struct p9_client client)
		{
		int i, n;
		int n;
		struct p9_conn *m;

		P9_DPRINTK(P9_DEBUG_MUX, "client %p msize %d\n", client, client->msize);
		@@ -590,15 +584,6 @@ static struct p9_conn p9_conn_create(struct p9_client client)
		set_bit(Wpending, &m->wsched);
		}

		for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
		if (IS_ERR(m->poll_wait[i].wait_addr)) {
		p9_mux_poll_stop(m);
		kfree(m);
		/* return the error code */
		return (void *)m->poll_wait[i].wait_addr;
		}
		}

		return m;
		}