Commit c058f6df authored Nov 02, 2019 by Florian Fainelli Committed by David S. Miller Nov 05, 2019

net: dsa: Fix use after free in dsa_switch_remove()



The order in which the ports are deleted from the list and freed and the
call to dsa_switch_remove() is done is reversed, which leads to an
use after free condition. Reverse the two: first tear down the ports and
switch from the fabric, then free the ports associated with that switch
fabric.

Fixes: 05f294a8 ("net: dsa: allocate ports on touch")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Vivien Didelot <vivien.didelot@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 2bceefbe

net/dsa/dsa2.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -874,12 +874,13 @@ static void dsa_switch_remove(struct dsa_switch *ds)
		struct dsa_switch_tree *dst = ds->dst;
		struct dsa_port dp, next;

		dsa_tree_teardown(dst);

		list_for_each_entry_safe(dp, next, &dst->ports, list) {
		list_del(&dp->list);
		kfree(dp);
		}

		dsa_tree_teardown(dst);
		dsa_tree_put(dst);
		}

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