Commit 30abc9cd authored Nov 19, 2020 by Christian Eggers Committed by Jakub Kicinski Nov 20, 2020

net: dsa: avoid potential use-after-free error



If dsa_switch_ops::port_txtstamp() returns false, clone will be freed
immediately. Shouldn't store a pointer to freed memory.

Signed-off-by: Christian Eggers <ceggers@arri.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Vladimir Oltean <olteanv@gmail.com>
Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20201119110906.25558-1-ceggers@arri.de


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

parent 2ed03e5a

net/dsa/slave.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -522,10 +522,10 @@ static void dsa_skb_tx_timestamp(struct dsa_slave_priv *p,
		if (!clone)
		return;

		if (ds->ops->port_txtstamp(ds, p->dp->index, clone, type)) {
		DSA_SKB_CB(skb)->clone = clone;

		if (ds->ops->port_txtstamp(ds, p->dp->index, clone, type))
		return;
		}

		kfree_skb(clone);
		}

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