On Thu, 5 Aug 2021 16:54:14 +0900 Takeshi Misawa wrote:
> If IEEE-802.15.4-RAW is closed before receive skb, skb is leaked.
> Fix this, by freeing sk_receive_queue in sk->sk_destruct().
>
> syzbot report:
> BUG: memory leak
> unreferenced object 0xffff88810f644600 (size 232):
> comm "softirq", pid 0, jiffies 4294967032 (age 81.270s)
> hex dump (first 32 bytes):
> 10 7d 4b 12 81 88 ff ff 10 7d 4b 12 81 88 ff ff .}K......}K.....
> 00 00 00 00 00 00 00 00 40 7c 4b 12 81 88 ff ff ........@|K.....
> backtrace:
> [<ffffffff83651d4a>] skb_clone+0xaa/0x2b0 net/core/skbuff.c:1496
> [<ffffffff83fe1b80>] ieee802154_raw_deliver net/ieee802154/socket.c:369 [inline]
> [<ffffffff83fe1b80>] ieee802154_rcv+0x100/0x340 net/ieee802154/socket.c:1070
> [<ffffffff8367cc7a>] __netif_receive_skb_one_core+0x6a/0xa0 net/core/dev.c:5384
> [<ffffffff8367cd07>] __netif_receive_skb+0x27/0xa0 net/core/dev.c:5498
> [<ffffffff8367cdd9>] netif_receive_skb_internal net/core/dev.c:5603 [inline]
> [<ffffffff8367cdd9>] netif_receive_skb+0x59/0x260 net/core/dev.c:5662
> [<ffffffff83fe6302>] ieee802154_deliver_skb net/mac802154/rx.c:29 [inline]
> [<ffffffff83fe6302>] ieee802154_subif_frame net/mac802154/rx.c:102 [inline]
> [<ffffffff83fe6302>] __ieee802154_rx_handle_packet net/mac802154/rx.c:212 [inline]
> [<ffffffff83fe6302>] ieee802154_rx+0x612/0x620 net/mac802154/rx.c:284
> [<ffffffff83fe59a6>] ieee802154_tasklet_handler+0x86/0xa0 net/mac802154/main.c:35
> [<ffffffff81232aab>] tasklet_action_common.constprop.0+0x5b/0x100 kernel/softirq.c:557
> [<ffffffff846000bf>] __do_softirq+0xbf/0x2ab kernel/softirq.c:345
> [<ffffffff81232f4c>] do_softirq kernel/softirq.c:248 [inline]
> [<ffffffff81232f4c>] do_softirq+0x5c/0x80 kernel/softirq.c:235
> [<ffffffff81232fc1>] __local_bh_enable_ip+0x51/0x60 kernel/softirq.c:198
> [<ffffffff8367a9a4>] local_bh_enable include/linux/bottom_half.h:32 [inline]
> [<ffffffff8367a9a4>] rcu_read_unlock_bh include/linux/rcupdate.h:745 [inline]
> [<ffffffff8367a9a4>] __dev_queue_xmit+0x7f4/0xf60 net/core/dev.c:4221
> [<ffffffff83fe2db4>] raw_sendmsg+0x1f4/0x2b0 net/ieee802154/socket.c:295
> [<ffffffff8363af16>] sock_sendmsg_nosec net/socket.c:654 [inline]
> [<ffffffff8363af16>] sock_sendmsg+0x56/0x80 net/socket.c:674
> [<ffffffff8363deec>] __sys_sendto+0x15c/0x200 net/socket.c:1977
> [<ffffffff8363dfb6>] __do_sys_sendto net/socket.c:1989 [inline]
> [<ffffffff8363dfb6>] __se_sys_sendto net/socket.c:1985 [inline]
> [<ffffffff8363dfb6>] __x64_sys_sendto+0x26/0x30 net/socket.c:1985
>
> Fixes: 9ec767160357 ("net: add IEEE 802.15.4 socket family implementation")
> Reported-and-tested-by: syzbot+1f68113fa907bf0695a8@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Takeshi Misawa <jeliantsurux@xxxxxxxxx>
> ---
> Dear David Howells, Jakub Kicinski
Please use scripts/get_maintainer.pl to find the people you should CC.
Adding Alexander and Stefan.
> syzbot reported memory leak in ieee802154_raw_deliver.
>
> I send a patch that passed syzbot reproducer test.
> Please consider this memory leak and patch.
>
> syzbot link:
> https://syzkaller.appspot.com/bug?id=8dd3bcb1dc757587adfb4dbb810fd24dd990283f
>
> Regards.
> ---
> net/ieee802154/socket.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/net/ieee802154/socket.c b/net/ieee802154/socket.c
> index a45a0401adc5..c25f7617770c 100644
> --- a/net/ieee802154/socket.c
> +++ b/net/ieee802154/socket.c
> @@ -984,6 +984,11 @@ static const struct proto_ops ieee802154_dgram_ops = {
> .sendpage = sock_no_sendpage,
> };
>
> +static void ieee802154_sock_destruct(struct sock *sk)
> +{
> + skb_queue_purge(&sk->sk_receive_queue);
> +}
> +
> /* Create a socket. Initialise the socket, blank the addresses
> * set the state.
> */
> @@ -1024,7 +1029,7 @@ static int ieee802154_create(struct net *net, struct socket *sock,
> sock->ops = ops;
>
> sock_init_data(sock, sk);
> - /* FIXME: sk->sk_destruct */
> + sk->sk_destruct = ieee802154_sock_destruct;
> sk->sk_family = PF_IEEE802154;
>
> /* Checksums on by default */
