netdev - [PATCH 2/2] 9p/trans_fd: put worker reqs on destroy

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Date:   Tue,  9 Oct 2018 06:05:56 +0200
From:   Dominique Martinet <asmadeus@...ewreck.org>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Dominique Martinet <dominique.martinet@....fr>,
        v9fs-developer@...ts.sourceforge.net, netdev@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Eric Van Hensbergen <ericvh@...il.com>,
        Latchesar Ionkov <lucho@...kov.net>,
        Tomas Bortoli <tomasbortoli@...il.com>
Subject: [PATCH 2/2] 9p/trans_fd: put worker reqs on destroy

From: Dominique Martinet <dominique.martinet@....fr>

p9_read_work/p9_write_work might still hold references to a req after
having been cancelled; make sure we put any of these to avoid potential
request leak on disconnect.

Fixes: 728356dedeff8 ("9p: Add refcount to p9_req_t")
Signed-off-by: Dominique Martinet <dominique.martinet@....fr>
Cc: Eric Van Hensbergen <ericvh@...il.com>
Cc: Latchesar Ionkov <lucho@...kov.net>
Cc: Tomas Bortoli <tomasbortoli@...il.com>
---
Noticed we could leak a ref while looking at the syzbot report,
this should be safe enough after the work has been cancelled...
Probably.

 net/9p/trans_fd.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/9p/trans_fd.c b/net/9p/trans_fd.c
index a0317d459cde..f868cf6fba79 100644
--- a/net/9p/trans_fd.c
+++ b/net/9p/trans_fd.c
@@ -876,7 +876,15 @@ static void p9_conn_destroy(struct p9_conn *m)
 
 	p9_mux_poll_stop(m);
 	cancel_work_sync(&m->rq);
+	if (m->rreq) {
+		p9_req_put(m->rreq);
+		m->rreq = NULL;
+	}
 	cancel_work_sync(&m->wq);
+	if (m->wreq) {
+		p9_req_put(m->wreq);
+		m->wreq = NULL;
+	}
 
 	p9_conn_cancel(m, -ECONNRESET);
 
-- 
2.19.1