[PATCH 4.4 03/31] net: Fix memory leak in ieee802154_raw_deliver

From: Sasha Levin
Date: Tue Aug 24 2021 - 13:40:02 EST


From: Takeshi Misawa <jeliantsurux@xxxxxxxxx>

[ Upstream commit 1090340f7ee53e824fd4eef66a4855d548110c5b ]

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>
Acked-by: Alexander Aring <aahringo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210805075414.GA15796@DESKTOP
Signed-off-by: Stefan Schmidt <stefan@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 cb6c0772ea36..42ab1b61b513 100644
--- a/net/ieee802154/socket.c
+++ b/net/ieee802154/socket.c
@@ -983,6 +983,11 @@ static const struct proto_ops ieee802154_dgram_ops = {
#endif
};

+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.
*/
@@ -1023,7 +1028,7 @@ 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 */
--
2.30.2