CVE-2022-48651

In the Linux kernel, the following vulnerability has been resolved: 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.