On Sun, 22 Nov 2020 10:34:56 +0800 Wang Hai wrote:
> kmemleak report a memory leak as follows:
>
> unreferenced object 0xffff8880059c6a00 (size 64):
> comm "ip", pid 23696, jiffies 4296590183 (age 1755.384s)
> hex dump (first 32 bytes):
> 20 01 00 10 00 00 00 00 00 00 00 00 00 00 00 00 ...............
> 1c 00 00 00 00 00 00 00 00 00 00 00 07 00 00 00 ................
> backtrace:
> [<00000000aa4e7a87>] ip6addrlbl_add+0x90/0xbb0
> [<0000000070b8d7f1>] ip6addrlbl_net_init+0x109/0x170
> [<000000006a9ca9d4>] ops_init+0xa8/0x3c0
> [<000000002da57bf2>] setup_net+0x2de/0x7e0
> [<000000004e52d573>] copy_net_ns+0x27d/0x530
> [<00000000b07ae2b4>] create_new_namespaces+0x382/0xa30
> [<000000003b76d36f>] unshare_nsproxy_namespaces+0xa1/0x1d0
> [<0000000030653721>] ksys_unshare+0x3a4/0x780
> [<0000000007e82e40>] __x64_sys_unshare+0x2d/0x40
> [<0000000031a10c08>] do_syscall_64+0x33/0x40
> [<0000000099df30e7>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
> We should free all rules when we catch an error in ip6addrlbl_net_init().
> otherwise a memory leak will occur.
>
> Fixes: 2a8cc6c89039 ("[IPV6] ADDRCONF: Support RFC3484 configurable address
> selection policy table.")
> Reported-by: Hulk Robot <hul...@huawei.com>
> Signed-off-by: Wang Hai <wangha...@huawei.com>
We can simplify this function.
> diff --git a/net/ipv6/addrlabel.c b/net/ipv6/addrlabel.c
> index 642fc6ac13d2..637e323a0224 100644
> --- a/net/ipv6/addrlabel.c
> +++ b/net/ipv6/addrlabel.c
> @@ -306,6 +306,8 @@ static int ip6addrlbl_del(struct net *net,
> /* add default label */
> static int __net_init ip6addrlbl_net_init(struct net *net)
> {
> + struct ip6addrlbl_entry *p = NULL;
> + struct hlist_node *n;
> int err = 0;
err does not need init
> int i;
>
> @@ -320,9 +322,17 @@ static int __net_init ip6addrlbl_net_init(struct net
> *net)
instead of the temporary ret variable we can assign directly to err
> ip6addrlbl_init_table[i].prefixlen,
> 0,
> ip6addrlbl_init_table[i].label, 0);
> - /* XXX: should we free all rules when we catch an error? */
> - if (ret && (!err || err != -ENOMEM))
> + if (ret && (!err || err != -ENOMEM)) {
this will become if (err)
> err = ret;
> + goto err_ip6addrlbl_add;
> + }
> + }
> + return err;
return 0;
> +err_ip6addrlbl_add:
> + hlist_for_each_entry_safe(p, n, &net->ipv6.ip6addrlbl_table.head, list)
> {
> + hlist_del_rcu(&p->list);
> + kfree_rcu(p, rcu);
> }
> return err;
> }
