diff options
| author | Lu Wei <luwei32@huawei.com> | 2022-09-07 13:12:04 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-09-09 14:46:06 +0300 |
| commit | 81225b2ea161af48e093f58e8dfee6d705b16af4 (patch) | |
| tree | e44a929e52ab40390f1fe8e16b61708df684e9eb /drivers/net/ipvlan | |
| parent | df2a60173a61a5acf44fca2cfb2d8d9f5b810a3f (diff) | |
| download | linux-81225b2ea161af48e093f58e8dfee6d705b16af4.tar.xz | |
ipvlan: Fix out-of-bound bugs caused by unset skb->mac_header
If an AF_PACKET socket is used to send packets through ipvlan and the
default xmit function of the AF_PACKET socket is changed from
dev_queue_xmit() to packet_direct_xmit() via setsockopt() with the option
name of PACKET_QDISC_BYPASS, the skb->mac_header may not be reset and
remains as the initial value of 65535, this may trigger slab-out-of-bounds
bugs as following:
=================================================================
UG: KASAN: slab-out-of-bounds in ipvlan_xmit_mode_l2+0xdb/0x330 [ipvlan]
PU: 2 PID: 1768 Comm: raw_send Kdump: loaded Not tainted 6.0.0-rc4+ #6
ardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-1.fc33
all Trace:
print_address_description.constprop.0+0x1d/0x160
print_report.cold+0x4f/0x112
kasan_report+0xa3/0x130
ipvlan_xmit_mode_l2+0xdb/0x330 [ipvlan]
ipvlan_start_xmit+0x29/0xa0 [ipvlan]
__dev_direct_xmit+0x2e2/0x380
packet_direct_xmit+0x22/0x60
packet_snd+0x7c9/0xc40
sock_sendmsg+0x9a/0xa0
__sys_sendto+0x18a/0x230
__x64_sys_sendto+0x74/0x90
do_syscall_64+0x3b/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd
The root cause is:
1. packet_snd() only reset skb->mac_header when sock->type is SOCK_RAW
and skb->protocol is not specified as in packet_parse_headers()
2. packet_direct_xmit() doesn't reset skb->mac_header as dev_queue_xmit()
In this case, skb->mac_header is 65535 when ipvlan_xmit_mode_l2() is
called. So when ipvlan_xmit_mode_l2() gets mac header with eth_hdr() which
use "skb->head + skb->mac_header", out-of-bound access occurs.
This patch replaces eth_hdr() with skb_eth_hdr() in ipvlan_xmit_mode_l2()
and reset mac header in multicast to solve this out-of-bound bug.
Fixes: 2ad7bf363841 ("ipvlan: Initial check-in of the IPVLAN driver.")
Signed-off-by: Lu Wei <luwei32@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ipvlan')
| -rw-r--r-- | drivers/net/ipvlan/ipvlan_core.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/net/ipvlan/ipvlan_core.c b/drivers/net/ipvlan/ipvlan_core.c index dfeb5b392e64..bb1c298c1e78 100644 --- a/drivers/net/ipvlan/ipvlan_core.c +++ b/drivers/net/ipvlan/ipvlan_core.c @@ -495,7 +495,6 @@ static int ipvlan_process_v6_outbound(struct sk_buff *skb) static int ipvlan_process_outbound(struct sk_buff *skb) { - struct ethhdr *ethh = eth_hdr(skb); int ret = NET_XMIT_DROP; /* The ipvlan is a pseudo-L2 device, so the packets that we receive @@ -505,6 +504,8 @@ static int ipvlan_process_outbound(struct sk_buff *skb) if (skb_mac_header_was_set(skb)) { /* In this mode we dont care about * multicast and broadcast traffic */ + struct ethhdr *ethh = eth_hdr(skb); + if (is_multicast_ether_addr(ethh->h_dest)) { pr_debug_ratelimited( "Dropped {multi|broad}cast of type=[%x]\n", @@ -589,7 +590,7 @@ out: static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev) { const struct ipvl_dev *ipvlan = netdev_priv(dev); - struct ethhdr *eth = eth_hdr(skb); + struct ethhdr *eth = skb_eth_hdr(skb); struct ipvl_addr *addr; void *lyr3h; int addr_type; @@ -619,6 +620,7 @@ static int ipvlan_xmit_mode_l2(struct sk_buff *skb, struct net_device *dev) return dev_forward_skb(ipvlan->phy_dev, skb); } else if (is_multicast_ether_addr(eth->h_dest)) { + skb_reset_mac_header(skb); ipvlan_skb_crossing_ns(skb, NULL); ipvlan_multicast_enqueue(ipvlan->port, skb, true); return NET_XMIT_SUCCESS; |