Commit 36118230 authored Nov 09, 2020 by Martin Schiller Committed by Jakub Kicinski Nov 11, 2020

net/x25: Fix null-ptr-deref in x25_connect



This fixes a regression for blocking connects introduced by commit
4becb7ee ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect").

The x25->neighbour is already set to "NULL" by x25_disconnect() now,
while a blocking connect is waiting in
x25_wait_for_connection_establishment(). Therefore x25->neighbour must
not be accessed here again and x25->state is also already set to
X25_STATE_0 by x25_disconnect().

Fixes: 4becb7ee ("net/x25: Fix x25_neigh refcnt leak when x25 disconnect")
Signed-off-by: Martin Schiller <ms@dev.tdt.de>
Reviewed-by: Xie He <xie.he.0141@gmail.com>
Link: https://lore.kernel.org/r/20201109065449.9014-1-ms@dev.tdt.de


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent df392aef

net/x25/af_x25.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -825,7 +825,7 @@ static int x25_connect(struct socket sock, struct sockaddr uaddr,
		sock->state = SS_CONNECTED;
		rc = 0;
		out_put_neigh:
		if (rc) {
		if (rc && x25->neighbour) {
		read_lock_bh(&x25_list_lock);
		x25_neigh_put(x25->neighbour);
		x25->neighbour = NULL;

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