[PATCH 4.4 64/92] net/core/neighbour: tell kmemleak about hash tables

Greg Kroah-Hartman
2019-12-04T17:59:46Z

From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>

[ Upstream commit 85704cb8dcfd88d351bfc87faaeba1c8214f3177 ]

This fixes false-positive kmemleak reports about leaked neighbour entries:

unreferenced object 0xffff8885c6e4d0a8 (size 1024):
comm "softirq", pid 0, jiffies 4294922664 (age 167640.804s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 20 2c f3 83 ff ff ff ff ........ ,......
08 c0 ef 5f 84 88 ff ff 01 8c 7d 02 01 00 00 00 ..._......}.....
backtrace:
[<00000000748509fe>] ip6_finish_output2+0x887/0x1e40
[<0000000036d7a0d8>] ip6_output+0x1ba/0x600
[<0000000027ea7dba>] ip6_send_skb+0x92/0x2f0
[<00000000d6e2111d>] udp_v6_send_skb.isra.24+0x680/0x15e0
[<000000000668a8be>] udpv6_sendmsg+0x18c9/0x27a0
[<000000004bd5fa90>] sock_sendmsg+0xb3/0xf0
[<000000008227b29f>] ___sys_sendmsg+0x745/0x8f0
[<000000008698009d>] __sys_sendmsg+0xde/0x170
[<00000000889dacf1>] do_syscall_64+0x9b/0x400
[<0000000081cdb353>] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[<000000005767ed39>] 0xffffffffffffffff

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/neighbour.c | 13 +++++++++----
1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index b3b242f7ecfd2..bba672482a0ef 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -18,6 +18,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/slab.h>
+#include <linux/kmemleak.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/module.h>
@@ -325,12 +326,14 @@ static struct neigh_hash_table *neigh_hash_alloc(unsigned int shift)
ret = kmalloc(sizeof(*ret), GFP_ATOMIC);
if (!ret)
return NULL;
- if (size <= PAGE_SIZE)
+ if (size <= PAGE_SIZE) {
buckets = kzalloc(size, GFP_ATOMIC);
- else
+ } else {
buckets = (struct neighbour __rcu **)
__get_free_pages(GFP_ATOMIC | __GFP_ZERO,
get_order(size));
+ kmemleak_alloc(buckets, size, 0, GFP_ATOMIC);
+ }
if (!buckets) {
kfree(ret);
return NULL;
@@ -350,10 +353,12 @@ static void neigh_hash_free_rcu(struct rcu_head *head)
size_t size = (1 << nht->hash_shift) * sizeof(struct neighbour *);
struct neighbour __rcu **buckets = nht->hash_buckets;

- if (size <= PAGE_SIZE)
+ if (size <= PAGE_SIZE) {
kfree(buckets);
- else
+ } else {
+ kmemleak_free(buckets);
free_pages((unsigned long)buckets, get_order(size));
+ }
kfree(nht);
}

--
2.20.1