Commit e255e11e authored Nov 24, 2020 by Wang Hai Committed by Jakub Kicinski Nov 25, 2020

ipv6: addrlabel: fix possible memory leak in ip6addrlbl_net_init



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: 2a8cc6c8 ("[IPV6] ADDRCONF: Support RFC3484 configurable address selection policy table.")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Link: https://lore.kernel.org/r/20201124071728.8385-1-wanghai38@huawei.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 6f7a1f9c

net/ipv6/addrlabel.c

+17 −9

Original line number	Diff line number	Diff line
		@@ -306,7 +306,9 @@ static int ip6addrlbl_del(struct net *net,
		/* add default label */
		static int __net_init ip6addrlbl_net_init(struct net *net)
		{
		int err = 0;
		struct ip6addrlbl_entry *p = NULL;
		struct hlist_node *n;
		int err;
		int i;

		ADDRLABEL(KERN_DEBUG "%s\n", __func__);
		@@ -315,14 +317,20 @@ static int __net_init ip6addrlbl_net_init(struct net *net)
		INIT_HLIST_HEAD(&net->ipv6.ip6addrlbl_table.head);

		for (i = 0; i < ARRAY_SIZE(ip6addrlbl_init_table); i++) {
		int ret = ip6addrlbl_add(net,
		err = ip6addrlbl_add(net,
		ip6addrlbl_init_table[i].prefix,
		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))
		err = ret;
		if (err)
		goto err_ip6addrlbl_add;
		}
		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;
		}

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