From: Stephen Hemminger <shemminger@vyatta.com>
Date: Sun, 10 Feb 2008 07:26:53 +0000 (-0800)
Subject: [PKT_SCHED] ematch: tcf_em_destroy robustness
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=954415e33ed6cfa932c13e8c2460bd05e50723b5;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

[PKT_SCHED] ematch: tcf_em_destroy robustness

Make the code in tcf_em_tree_destroy more robust and cleaner:
 * Don't need to cast pointer to kfree() or avoid passing NULL.
 * After freeing the tree, clear the pointer to avoid possible problems
from repeated free.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/ematch.c b/net/sched/ematch.c
index d421ec728ee7..b29439ddcf71 100644
--- a/net/sched/ematch.c
+++ b/net/sched/ematch.c
@@ -409,14 +409,15 @@ void tcf_em_tree_destroy(struct tcf_proto *tp, struct tcf_ematch_tree *tree)
 		if (em->ops) {
 			if (em->ops->destroy)
 				em->ops->destroy(tp, em);
-			else if (!tcf_em_is_simple(em) && em->data)
-				kfree((void *) em->data);
+			else if (!tcf_em_is_simple(em))
+				kfree(em->data);
 			module_put(em->ops->owner);
 		}
 	}
 
 	tree->hdr.nmatches = 0;
 	kfree(tree->matches);
+	tree->matches = NULL;
 }
 EXPORT_SYMBOL(tcf_em_tree_destroy);