net/core/neighbour: tell kmemleak about hash tables

BugLink: https://bugs.launchpad.net/bugs/1855787
[ 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>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 25ea8e5b490ac3f468f8f0f37db00b8ad2d5150a..b4d64f4a6dc04b257d17da8075fe0f08e8eab7e2 100644 (file)
--- 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>
@@ -361,12 +362,14 @@ 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;
@@ -386,10 +389,12 @@ 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);
 }