net: sched: fix possible null pointer deref in tcf_block_put

We need to check block for being null in both tcf_block_put and tcf_block_put_ext. Fixes: 343723d ("net: sched: fix clsact init error path") Reported-by: Prashant Bhole <[email protected]> Signed-off-by: Jiri Pirko <[email protected]> Signed-off-by: David S. Miller <[email protected]>
opendata26 · Dec 26, 2017 · 4853f12 · 4853f12
1 parent 0a3d805
commit 4853f12
Showing 1 changed file with 2 additions and 0 deletions.
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
@@ -379,6 +379,8 @@ void tcf_block_put(struct tcf_block *block)
 {
 	struct tcf_block_ext_info ei = {0, };
 
+	if (!block)
+		return;
 	tcf_block_put_ext(block, block->q, &ei);
 }