On 01/08/2019 01:30 AM, Konstantin Khlebnikov wrote:
> This fixes false-positive kmemleak reports about leaked neighbour entries:
>
> unreferenced object 0xffff8885c6e4d0a8 (size 1024):
size 1024 object : should have been allocated by kzalloc(), right ?
> 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 <khlebni...@yandex-team.ru>
> ---
> 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 763a7b08df67..3e27a779f288 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>
> @@ -443,12 +444,14 @@ 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;
> @@ -468,10 +471,12 @@ 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);
> }
>
>
