linux-stable.git/include/net, branch v5.4.138

net: llc: fix skb_over_panic

2021-08-04T10:27:39+00:00

[ Upstream commit c7c9d2102c9c098916ab9e0ab248006107d00d6c ]

Syzbot reported skb_over_panic() in llc_pdu_init_as_xid_cmd(). The
problem was in wrong LCC header manipulations.

Syzbot's reproducer tries to send XID packet. llc_ui_sendmsg() is
doing following steps:

	1. skb allocation with size = len + header size
		len is passed from userpace and header size
		is 3 since addr->sllc_xid is set.

	2. skb_reserve() for header_len = 3
	3. filling all other space with memcpy_from_msg()

Ok, at this moment we have fully loaded skb, only headers needs to be
filled.

Then code comes to llc_sap_action_send_xid_c(). This function pushes 3
bytes for LLC PDU header and initializes it. Then comes
llc_pdu_init_as_xid_cmd(). It initalizes next 3 bytes *AFTER* LLC PDU
header and call skb_push(skb, 3). This looks wrong for 2 reasons:

	1. Bytes rigth after LLC header are user data, so this function
	   was overwriting payload.

	2. skb_push(skb, 3) call can cause skb_over_panic() since
	   all free space was filled in llc_ui_sendmsg(). (This can
	   happen is user passed 686 len: 686 + 14 (eth header) + 3 (LLC
	   header) = 703. SKB_DATA_ALIGN(703) = 704)

So, in this patch I added 2 new private constansts: LLC_PDU_TYPE_U_XID
and LLC_PDU_LEN_U_XID. LLC_PDU_LEN_U_XID is used to correctly reserve
header size to handle LLC + XID case. LLC_PDU_TYPE_U_XID is used by
llc_pdu_header_init() function to push 6 bytes instead of 3. And finally
I removed skb_push() call from llc_pdu_init_as_xid_cmd().

This changes should not affect other parts of LLC, since after
all steps we just transmit buffer.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-and-tested-by: syzbot+5e5a981ad7cc54c4b2b4@syzkaller.appspotmail.com
Signed-off-by: Pavel Skripkin 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

sctp: move 198 addresses from unusable to private scope

2021-07-31T06:19:38+00:00

[ Upstream commit 1d11fa231cabeae09a95cb3e4cf1d9dd34e00f08 ]

The doc draft-stewart-tsvwg-sctp-ipv4-00 that restricts 198 addresses
was never published. These addresses as private addresses should be
allowed to use in SCTP.

As Michael Tuexen suggested, this patch is to move 198 addresses from
unusable to private scope.

Reported-by: Sérgio 
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: annotate data race around sk_ll_usec

2021-07-31T06:19:38+00:00

[ Upstream commit 0dbffbb5335a1e3aa6855e4ee317e25e669dd302 ]

sk_ll_usec is read locklessly from sk_can_busy_loop()
while another thread can change its value in sock_setsockopt()

This is correct but needs annotations.

BUG: KCSAN: data-race in __skb_try_recv_datagram / sock_setsockopt

write to 0xffff88814eb5f904 of 4 bytes by task 14011 on cpu 0:
 sock_setsockopt+0x1287/0x2090 net/core/sock.c:1175
 __sys_setsockopt+0x14f/0x200 net/socket.c:2100
 __do_sys_setsockopt net/socket.c:2115 [inline]
 __se_sys_setsockopt net/socket.c:2112 [inline]
 __x64_sys_setsockopt+0x62/0x70 net/socket.c:2112
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff88814eb5f904 of 4 bytes by task 14001 on cpu 1:
 sk_can_busy_loop include/net/busy_poll.h:41 [inline]
 __skb_try_recv_datagram+0x14f/0x320 net/core/datagram.c:273
 unix_dgram_recvmsg+0x14c/0x870 net/unix/af_unix.c:2101
 unix_seqpacket_recvmsg+0x5a/0x70 net/unix/af_unix.c:2067
 ____sys_recvmsg+0x15d/0x310 include/linux/uio.h:244
 ___sys_recvmsg net/socket.c:2598 [inline]
 do_recvmmsg+0x35c/0x9f0 net/socket.c:2692
 __sys_recvmmsg net/socket.c:2771 [inline]
 __do_sys_recvmmsg net/socket.c:2794 [inline]
 __se_sys_recvmmsg net/socket.c:2787 [inline]
 __x64_sys_recvmmsg+0xcf/0x150 net/socket.c:2787
 do_syscall_64+0x4a/0x90 arch/x86/entry/common.c:47
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0x00000000 -> 0x00000101

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 14001 Comm: syz-executor.3 Not tainted 5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: validate lwtstate->data before returning from skb_tunnel_info()

2021-07-25T12:35:15+00:00

commit 67a9c94317402b826fc3db32afc8f39336803d97 upstream.

skb_tunnel_info() returns pointer of lwtstate->data as ip_tunnel_info
type without validation. lwtstate->data can have various types such as
mpls_iptunnel_encap, etc and these are not compatible.
So skb_tunnel_info() should validate before returning that pointer.

Splat looks like:
BUG: KASAN: slab-out-of-bounds in vxlan_get_route+0x418/0x4b0 [vxlan]
Read of size 2 at addr ffff888106ec2698 by task ping/811

CPU: 1 PID: 811 Comm: ping Not tainted 5.13.0+ #1195
Call Trace:
 dump_stack_lvl+0x56/0x7b
 print_address_description.constprop.8.cold.13+0x13/0x2ee
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 kasan_report.cold.14+0x83/0xdf
 ? vxlan_get_route+0x418/0x4b0 [vxlan]
 vxlan_get_route+0x418/0x4b0 [vxlan]
 [ ... ]
 vxlan_xmit_one+0x148b/0x32b0 [vxlan]
 [ ... ]
 vxlan_xmit+0x25c5/0x4780 [vxlan]
 [ ... ]
 dev_hard_start_xmit+0x1ae/0x6e0
 __dev_queue_xmit+0x1f39/0x31a0
 [ ... ]
 neigh_xmit+0x2f9/0x940
 mpls_xmit+0x911/0x1600 [mpls_iptunnel]
 lwtunnel_xmit+0x18f/0x450
 ip_finish_output2+0x867/0x2040
 [ ... ]

Fixes: 61adedf3e3f1 ("route: move lwtunnel state to dst_entry")
Signed-off-by: Taehee Yoo 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: ipv6: fix return value of ip6_skb_dst_mtu

2021-07-25T12:35:14+00:00

commit 40fc3054b45820c28ea3c65e2c86d041dc244a8a upstream.

Commit 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE") introduced
ip6_skb_dst_mtu with return value of signed int which is inconsistent
with actually returned values. Also 2 users of this function actually
assign its value to unsigned int variable and only __xfrm6_output
assigns result of this function to signed variable but actually uses
as unsigned in further comparisons and calls. Change this function
to return unsigned int value.

Fixes: 628a5c561890 ("[INET]: Add IP(V6)_PMTUDISC_RPOBE")
Reviewed-by: David Ahern 
Signed-off-by: Vadim Fedorenko 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

sctp: validate from_addr_param return

2021-07-19T06:53:13+00:00

[ Upstream commit 0c5dc070ff3d6246d22ddd931f23a6266249e3db ]

Ilja reported that, simply putting it, nothing was validating that
from_addr_param functions were operating on initialized memory. That is,
the parameter itself was being validated by sctp_walk_params, but it
doesn't check for types and their specific sizes and it could be a 0-length
one, causing from_addr_param to potentially work over the next parameter or
even uninitialized memory.

The fix here is to, in all calls to from_addr_param, check if enough space
is there for the wanted IP address type.

Reported-by: Ilja Van Sprundel 
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: lwtunnel: handle MTU calculation in forwading

2021-07-14T14:53:35+00:00

[ Upstream commit fade56410c22cacafb1be9f911a0afd3701d8366 ]

Commit 14972cbd34ff ("net: lwtunnel: Handle fragmentation") moved
fragmentation logic away from lwtunnel by carry encap headroom and
use it in output MTU calculation. But the forwarding part was not
covered and created difference in MTU for output and forwarding and
further to silent drops on ipv4 forwarding path. Fix it by taking
into account lwtunnel encap headroom.

The same commit also introduced difference in how to treat RTAX_MTU
in IPv4 and IPv6 where latter explicitly removes lwtunnel encap
headroom from route MTU. Make IPv4 version do the same.

Fixes: 14972cbd34ff ("net: lwtunnel: Handle fragmentation")
Suggested-by: David Ahern 
Signed-off-by: Vadim Fedorenko 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: sched: add barrier to ensure correct ordering for lockless qdisc

2021-07-14T14:53:31+00:00

[ Upstream commit 89837eb4b2463c556a123437f242d6c2bc62ce81 ]

The spin_trylock() was assumed to contain the implicit
barrier needed to ensure the correct ordering between
STATE_MISSED setting/clearing and STATE_MISSED checking
in commit a90c57f2cedd ("net: sched: fix packet stuck
problem for lockless qdisc").

But it turns out that spin_trylock() only has load-acquire
semantic, for strongly-ordered system(like x86), the compiler
barrier implicitly contained in spin_trylock() seems enough
to ensure the correct ordering. But for weakly-orderly system
(like arm64), the store-release semantic is needed to ensure
the correct ordering as clear_bit() and test_bit() is store
operation, see queued_spin_lock().

So add the explicit barrier to ensure the correct ordering
for the above case.

Fixes: a90c57f2cedd ("net: sched: fix packet stuck problem for lockless qdisc")
Signed-off-by: Yunsheng Lin 
Acked-by: Jakub Kicinski 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net/sched: act_vlan: Fix modify to allow 0

2021-07-14T14:53:27+00:00

[ Upstream commit 9c5eee0afca09cbde6bd00f77876754aaa552970 ]

Currently vlan modification action checks existence of vlan priority by
comparing it to 0. Therefore it is impossible to modify existing vlan
tag to have priority 0.

For example, the following tc command will change the vlan id but will
not affect vlan priority:

tc filter add dev eth1 ingress matchall action vlan modify id 300 \
        priority 0 pipe mirred egress redirect dev eth2

The incoming packet on eth1:

ethertype 802.1Q (0x8100), vlan 200, p 4, ethertype IPv4

will be changed to:

ethertype 802.1Q (0x8100), vlan 300, p 4, ethertype IPv4

although the user has intended to have p == 0.

The fix is to add tcfv_push_prio_exists flag to struct tcf_vlan_params
and rely on it when deciding to set the priority.

Fixes: 45a497f2d149a4a8061c (net/sched: act_vlan: Introduce TCA_VLAN_ACT_MODIFY vlan action)
Signed-off-by: Boris Sukholitko 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

xfrm: xfrm_state_mtu should return at least 1280 for ipv6

2021-07-14T14:53:26+00:00

[ Upstream commit b515d2637276a3810d6595e10ab02c13bfd0b63a ]

Jianwen reported that IPv6 Interoperability tests are failing in an
IPsec case where one of the links between the IPsec peers has an MTU
of 1280. The peer generates a packet larger than this MTU, the router
replies with a "Packet too big" message indicating an MTU of 1280.
When the peer tries to send another large packet, xfrm_state_mtu
returns 1280 - ipsec_overhead, which causes ip6_setup_cork to fail
with EINVAL.

We can fix this by forcing xfrm_state_mtu to return IPV6_MIN_MTU when
IPv6 is used. After going through IPsec, the packet will then be
fragmented to obey the actual network's PMTU, just before leaving the
host.

Currently, TFC padding is capped to PMTU - overhead to avoid
fragementation: after padding and encapsulation, we still fit within
the PMTU. That behavior is preserved in this patch.

Fixes: 91657eafb64b ("xfrm: take net hdr len into account for esp payload size calculation")
Reported-by: Jianwen Ji 
Signed-off-by: Sabrina Dubroca 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin