net_sched: check NULL in tcf_block_put()

Callers of tcf_block_put() could pass NULL so
we can't use block->q before checking if block is
NULL or not.

tcf_block_put_ext() callers are fine, it is always
non-NULL.

Fixes: 8c4083b30e ("net: sched: add block bind/unbind notif. and extended block_get/put")
Reported-by: Dave Taht <dave.taht@gmail.com>
Cc: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Cong Wang 2017-11-02 17:32:08 -07:00 committed by David S. Miller
parent f67971e683
commit 8f918d3ff4

View File

@ -340,9 +340,6 @@ void tcf_block_put_ext(struct tcf_block *block,
{
struct tcf_chain *chain, *tmp;
if (!block)
return;
list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
tcf_chain_flush(chain);
@ -362,6 +359,8 @@ void tcf_block_put(struct tcf_block *block)
{
struct tcf_block_ext_info ei = {0, };
if (!block)
return;
tcf_block_put_ext(block, NULL, block->q, &ei);
}