Commits
Jiri Pirko committed 255cd50f207
net: sched: fix use-after-free in tcf_action_destroy and tcf_del_walker
Recent commit d7fb60b9cafb ("net_sched: get rid of tcfa_rcu") removed
freeing in call_rcu, which changed already existing hard-to-hit
race condition into 100% hit:
[ 598.599825] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
[ 598.607782] IP: tcf_action_destroy+0xc0/0x140
Or:
[ 40.858924] BUG: unable to handle kernel NULL pointer dereference at 0000000000000030
[ 40.862840] IP: tcf_generic_walker+0x534/0x820
Fix this by storing the ops and use them directly for module_put call.
Fixes: a85a970af265 ("net_sched: move tc_action into tcf_common")
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>