linux.git/net/packet, branch v5.1

packet: validate msg_namelen in send directly

2019-05-01T15:28:35+00:00

Packet sockets in datagram mode take a destination address. Verify its
length before passing to dev_hard_header.

Prior to 2.6.14-rc3, the send code ignored sll_halen. This is
established behavior. Directly compare msg_namelen to dev->addr_len.

Change v1->v2: initialize addr in all paths

Fixes: 6b8d95f1795c4 ("packet: validate address length if non-zero")
Suggested-by: David Laight 
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller

packet: in recvmsg msg_name return at least sizeof sockaddr_ll

2019-05-01T15:27:55+00:00

Packet send checks that msg_name is at least sizeof sockaddr_ll.
Packet recv must return at least this length, so that its output
can be passed unmodified to packet send.

This ceased to be true since adding support for lladdr longer than
sll_addr. Since, the return value uses true address length.

Always return at least sizeof sockaddr_ll, even if address length
is shorter. Zero the padding bytes.

Change v1->v2: do not overwrite zeroed padding again. use copy_len.

Fixes: 0fb375fb9b93 ("[AF_PACKET]: Allow for > 8 byte hardware addresses.")
Suggested-by: David Laight 
Signed-off-by: Willem de Bruijn 
Signed-off-by: David S. Miller

net/packet: Set __GFP_NOWARN upon allocation in alloc_pg_vec

2019-03-20T17:46:50+00:00

Since commit fc62814d690c ("net/packet: fix 4gb buffer limit due to overflow check")
one can now allocate packet ring buffers >= UINT_MAX. However, syzkaller
found that that triggers a warning:

[   21.100000] WARNING: CPU: 2 PID: 2075 at mm/page_alloc.c:4584 __alloc_pages_nod0
[   21.101490] Modules linked in:
[   21.101921] CPU: 2 PID: 2075 Comm: syz-executor.0 Not tainted 5.0.0 #146
[   21.102784] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
[   21.103887] RIP: 0010:__alloc_pages_nodemask+0x2a0/0x630
[   21.104640] Code: fe ff ff 65 48 8b 04 25 c0 de 01 00 48 05 90 0f 00 00 41 bd 01 00 00 00 48 89 44 24 48 e9 9c fe 3
[   21.107121] RSP: 0018:ffff88805e1cf920 EFLAGS: 00010246
[   21.107819] RAX: 0000000000000000 RBX: ffffffff85a488a0 RCX: 0000000000000000
[   21.108753] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000000
[   21.109699] RBP: 1ffff1100bc39f28 R08: ffffed100bcefb67 R09: ffffed100bcefb67
[   21.110646] R10: 0000000000000001 R11: ffffed100bcefb66 R12: 000000000000000d
[   21.111623] R13: 0000000000000000 R14: ffff88805e77d888 R15: 000000000000000d
[   21.112552] FS:  00007f7c7de05700(0000) GS:ffff88806d100000(0000) knlGS:0000000000000000
[   21.113612] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   21.114405] CR2: 000000000065c000 CR3: 000000005e58e006 CR4: 00000000001606e0
[   21.115367] Call Trace:
[   21.115705]  ? __alloc_pages_slowpath+0x21c0/0x21c0
[   21.116362]  alloc_pages_current+0xac/0x1e0
[   21.116923]  kmalloc_order+0x18/0x70
[   21.117393]  kmalloc_order_trace+0x18/0x110
[   21.117949]  packet_set_ring+0x9d5/0x1770
[   21.118524]  ? packet_rcv_spkt+0x440/0x440
[   21.119094]  ? lock_downgrade+0x620/0x620
[   21.119646]  ? __might_fault+0x177/0x1b0
[   21.120177]  packet_setsockopt+0x981/0x2940
[   21.120753]  ? __fget+0x2fb/0x4b0
[   21.121209]  ? packet_release+0xab0/0xab0
[   21.121740]  ? sock_has_perm+0x1cd/0x260
[   21.122297]  ? selinux_secmark_relabel_packet+0xd0/0xd0
[   21.123013]  ? __fget+0x324/0x4b0
[   21.123451]  ? selinux_netlbl_socket_setsockopt+0x101/0x320
[   21.124186]  ? selinux_netlbl_sock_rcv_skb+0x3a0/0x3a0
[   21.124908]  ? __lock_acquire+0x529/0x3200
[   21.125453]  ? selinux_socket_setsockopt+0x5d/0x70
[   21.126075]  ? __sys_setsockopt+0x131/0x210
[   21.126533]  ? packet_release+0xab0/0xab0
[   21.127004]  __sys_setsockopt+0x131/0x210
[   21.127449]  ? kernel_accept+0x2f0/0x2f0
[   21.127911]  ? ret_from_fork+0x8/0x50
[   21.128313]  ? do_raw_spin_lock+0x11b/0x280
[   21.128800]  __x64_sys_setsockopt+0xba/0x150
[   21.129271]  ? lockdep_hardirqs_on+0x37f/0x560
[   21.129769]  do_syscall_64+0x9f/0x450
[   21.130182]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

We should allocate with __GFP_NOWARN to handle this.

Cc: Kal Conley 
Cc: Andrey Konovalov 
Fixes: fc62814d690c ("net/packet: fix 4gb buffer limit due to overflow check")
Signed-off-by: Christoph Paasch 
Signed-off-by: David S. Miller

af_packet: fix the tx skb protocol in raw sockets with ETH_P_ALL

2019-03-19T01:11:40+00:00

I am using "protocol ip" filters in TC to manipulate TC flower
classifiers, which are only available with "protocol ip". However,
I faced an issue that packets sent via raw sockets with ETH_P_ALL
did not match the ip filters even if they did satisfy the condition
(e.g., DHCP offer from dhcpd).

I have determined that the behavior was caused by an unexpected
value stored in skb->protocol, namely, ETH_P_ALL instead of ETH_P_IP,
when packets were sent via raw sockets with ETH_P_ALL set.

IMHO, storing ETH_P_ALL in skb->protocol is not appropriate for
packets sent via raw sockets because ETH_P_ALL is not a real ether
type used on wire, but a virtual one.

This patch fixes the tx protocol selection in cases of transmission
via raw sockets created with ETH_P_ALL so that it asks the driver to
extract protocol from the Ethernet header.

Fixes: 75c65772c3 ("net/packet: Ask driver for protocol if not provided by user")
Signed-off-by: Yoshiki Komachi 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller

packets: Always register packet sk in the same order

2019-03-19T00:58:39+00:00

When using fanouts with AF_PACKET, the demux functions such as
fanout_demux_cpu will return an index in the fanout socket array, which
corresponds to the selected socket.

The ordering of this array depends on the order the sockets were added
to a given fanout group, so for FANOUT_CPU this means sockets are bound
to cpus in the order they are configured, which is OK.

However, when stopping then restarting the interface these sockets are
bound to, the sockets are reassigned to the fanout group in the reverse
order, due to the fact that they were inserted at the head of the
interface's AF_PACKET socket list.

This means that traffic that was directed to the first socket in the
fanout group is now directed to the last one after an interface restart.

In the case of FANOUT_CPU, traffic from CPU0 will be directed to the
socket that used to receive traffic from the last CPU after an interface
restart.

This commit introduces a helper to add a socket at the tail of a list,
then uses it to register AF_PACKET sockets.

Note that this changes the order in which sockets are listed in /proc and
with sock_diag.

Fixes: dc99f600698d ("packet: Add fanout support")
Signed-off-by: Maxime Chevallier 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller

net/packet: Remove redundant skb->protocol set

2019-02-22T20:55:31+00:00

c72219b75f introduced tpacket_set_protocol that parses the Ethernet L2
header and sets skb->protocol if it's unset. It is no longer needed
since the introduction of packet_parse_headers. In case of SOCK_RAW and
unset skb->protocol, packet_parse_headers asks the driver to tell the
protocol number, and it's implemented for all Ethernet devices. As the
old function supported only Ethernet, no functionality is lost.

Signed-off-by: Maxim Mikityanskiy 
Signed-off-by: David S. Miller

net/packet: Ask driver for protocol if not provided by user

2019-02-22T20:55:31+00:00

If a socket was created with socket(AF_PACKET, SOCK_RAW, 0), the
protocol number is unavailable. Try to ask the driver to extract it from
the L2 header in order for skb_try_probe_transport_header to succeed.

Signed-off-by: Maxim Mikityanskiy 
Signed-off-by: David S. Miller

net: Don't set transport offset to invalid value

2019-02-22T20:55:31+00:00

If the socket was created with socket(AF_PACKET, SOCK_RAW, 0),
skb->protocol will be unset, __skb_flow_dissect() will fail, and
skb_probe_transport_header() will fall back to the offset_hint, making
the resulting skb_transport_offset incorrect.

If, however, there is no transport header in the packet,
transport_header shouldn't be set to an arbitrary value.

Fix it by leaving the transport offset unset if it couldn't be found, to
be explicit rather than to fill it with some wrong value. It changes the
behavior, but if some code relied on the old behavior, it would be
broken anyway, as the old one is incorrect.

Signed-off-by: Maxim Mikityanskiy 
Signed-off-by: David S. Miller

net/packet: fix 4gb buffer limit due to overflow check

2019-02-12T18:37:23+00:00

When calculating rb->frames_per_block * req->tp_block_nr the result
can overflow. Check it for overflow without limiting the total buffer
size to UINT_MAX.

This change fixes support for packet ring buffers >= UINT_MAX.

Fixes: 8f8d28e4d6d8 ("net/packet: fix overflow in check for tp_frame_nr")
Signed-off-by: Kal Conley 
Signed-off-by: David S. Miller

af_packet: fix raw sockets over 6in4 tunnel

2019-01-17T23:54:45+00:00

Since commit cb9f1b783850, scapy (which uses an AF_PACKET socket in
SOCK_RAW mode) is unable to send a basic icmp packet over a sit tunnel:

Here is a example of the setup:
$ ip link set ntfp2 up
$ ip addr add 10.125.0.1/24 dev ntfp2
$ ip tunnel add tun1 mode sit ttl 64 local 10.125.0.1 remote 10.125.0.2 dev ntfp2
$ ip addr add fd00:cafe:cafe::1/128 dev tun1
$ ip link set dev tun1 up
$ ip route add fd00:200::/64 dev tun1
$ scapy
>>> p = []
>>> p += IPv6(src='fd00:100::1', dst='fd00:200::1')/ICMPv6EchoRequest()
>>> send(p, count=1, inter=0.1)
>>> quit()
$ ip -s link ls dev tun1 | grep -A1 "TX.*errors"
    TX: bytes  packets  errors  dropped carrier collsns
    0          0        1       0       0       0

The problem is that the network offset is set to the hard_header_len of the
output device (tun1, ie 14 + 20) and in our case, because the packet is
small (48 bytes) the pskb_inet_may_pull() fails (it tries to pull 40 bytes
(ipv6 header) starting from the network offset).

This problem is more generally related to device with variable hard header
length. To avoid a too intrusive patch in the current release, a (ugly)
workaround is proposed in this patch. It has to be cleaned up in net-next.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=993675a3100b1
Link: http://patchwork.ozlabs.org/patch/1024489/
Fixes: cb9f1b783850 ("ip: validate header length on virtual device xmit")
CC: Willem de Bruijn 
CC: Maxim Mikityanskiy 
Signed-off-by: Nicolas Dichtel 
Acked-by: Willem de Bruijn 
Signed-off-by: David S. Miller