linux-stable.git/include/linux/netfilter.h, branch v4.18.19

netfilter: avoid erronous array bounds warning

2018-11-04T13:51:43+00:00

[ Upstream commit 421c119f558761556afca6a62ad183bc2d8659e0 ]

Unfortunately some versions of gcc emit following warning:
  $ make net/xfrm/xfrm_output.o
  linux/compiler.h:252:20: warning: array subscript is above array bounds [-Warray-bounds]
  hook_head = rcu_dereference(net->nf.hooks_arp[hook]);
                            ^~~~~~~~~~~~~~~~~~~~~
xfrm_output_resume passes skb_dst(skb)->ops->family as its 'pf' arg so compiler
can't know that we'll never access hooks_arp[].
(NFPROTO_IPV4 or NFPROTO_IPV6 are only possible cases).

Avoid this by adding an explicit WARN_ON_ONCE() check.

This patch has no effect if the family is a compile-time constant as gcc
will remove the switch() construct entirely.

Reported-by: David Ahern 
Signed-off-by: Florian Westphal 
Reviewed-by: David Ahern 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: fix null-ptr-deref in nf_nat_decode_session

2018-06-12T17:12:43+00:00

Add null check for nat_hook in nf_nat_decode_session()

[  195.648098] UBSAN: Undefined behaviour in ./include/linux/netfilter.h:348:14
[  195.651366] BUG: KASAN: null-ptr-deref in __xfrm_policy_check+0x208/0x1d70
[  195.653888] member access within null pointer of type 'struct nf_nat_hook'
[  195.653896] CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.17.0-rc6+ #5
[  195.656320] Read of size 8 at addr 0000000000000008 by task ping/2469
[  195.658715] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
[  195.658721] Call Trace:
[  195.661087]
[  195.669341]  
[  195.670574]  dump_stack+0xc6/0x150
[  195.672156]  ? dump_stack_print_info.cold.0+0x1b/0x1b
[  195.674121]  ? ubsan_prologue+0x31/0x92
[  195.676546]  ubsan_epilogue+0x9/0x49
[  195.678159]  handle_null_ptr_deref+0x11a/0x130
[  195.679800]  ? sprint_OID+0x1a0/0x1a0
[  195.681322]  __ubsan_handle_type_mismatch_v1+0xd5/0x11d
[  195.683146]  ? ubsan_prologue+0x92/0x92
[  195.684642]  __xfrm_policy_check+0x18ef/0x1d70
[  195.686294]  ? rt_cache_valid+0x118/0x180
[  195.687804]  ? __xfrm_route_forward+0x410/0x410
[  195.689463]  ? fib_multipath_hash+0x700/0x700
[  195.691109]  ? kvm_sched_clock_read+0x23/0x40
[  195.692805]  ? pvclock_clocksource_read+0xf6/0x280
[  195.694409]  ? graph_lock+0xa0/0xa0
[  195.695824]  ? pvclock_clocksource_read+0xf6/0x280
[  195.697508]  ? pvclock_read_flags+0x80/0x80
[  195.698981]  ? kvm_sched_clock_read+0x23/0x40
[  195.700347]  ? sched_clock+0x5/0x10
[  195.701525]  ? sched_clock_cpu+0x18/0x1a0
[  195.702846]  tcp_v4_rcv+0x1d32/0x1de0
[  195.704115]  ? lock_repin_lock+0x70/0x270
[  195.707072]  ? pvclock_read_flags+0x80/0x80
[  195.709302]  ? tcp_v4_early_demux+0x4b0/0x4b0
[  195.711833]  ? lock_acquire+0x195/0x380
[  195.714222]  ? ip_local_deliver_finish+0xfc/0x770
[  195.716967]  ? raw_rcv+0x2b0/0x2b0
[  195.718856]  ? lock_release+0xa00/0xa00
[  195.720938]  ip_local_deliver_finish+0x1b9/0x770
[...]

Fixes: 2c205dd3981f ("netfilter: add struct nf_nat_hook and use it")
Signed-off-by: Prashant Bhole 
Acked-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nfnetlink_queue: resolve clash for unconfirmed conntracks

2018-05-23T07:26:08+00:00

In nfqueue, two consecutive skbuffs may race to create the conntrack
entry. Hence, the one that loses the race gets dropped due to clash in
the insertion into the hashes from the nf_conntrack_confirm() path.

This patch adds a new nf_conntrack_update() function which searches for
possible clashes and resolve them. NAT mangling for the packet losing
race is corrected by using the conntrack information that won race.

In order to avoid direct module dependencies with conntrack and NAT, the
nf_ct_hook and nf_nat_hook structures are used for this purpose.

Signed-off-by: Pablo Neira Ayuso

netfilter: add struct nf_nat_hook and use it

2018-05-23T07:26:07+00:00

Move decode_session() and parse_nat_setup_hook() indirections to struct
nf_nat_hook structure.

Signed-off-by: Pablo Neira Ayuso

netfilter: add struct nf_ct_hook and use it

2018-05-23T07:26:06+00:00

Move the nf_ct_destroy indirection to the struct nf_ct_hook.

Signed-off-by: Pablo Neira Ayuso

netfilter: lift one-nat-hook-only restriction

2018-05-23T07:14:06+00:00

This reverts commit f92b40a8b2645
("netfilter: core: only allow one nat hook per hook point"), this
limitation is no longer needed.  The nat core now invokes these
functions and makes sure that hook evaluation stops after a mapping is
created and a null binding is created otherwise.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: remove struct nf_afinfo and its helper functions

2018-01-08T17:11:02+00:00

This abstraction has no clients anymore, remove it.

This is what remains from previous authors, so correct copyright
statement after recent modifications and code removal.

Signed-off-by: Pablo Neira Ayuso

netfilter: remove route_key_size field in struct nf_afinfo

2018-01-08T17:11:01+00:00

This is only needed by nf_queue, place this code where it belongs.

Signed-off-by: Pablo Neira Ayuso

netfilter: move reroute indirection to struct nf_ipv6_ops

2018-01-08T17:10:53+00:00

We cannot make a direct call to nf_ip6_reroute() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define reroute indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso

netfilter: move route indirection to struct nf_ipv6_ops

2018-01-08T17:01:26+00:00

We cannot make a direct call to nf_ip6_route() because that would result
in autoloading the 'ipv6' module because of symbol dependencies.
Therefore, define route indirection in nf_ipv6_ops where this really
belongs to.

For IPv4, we can indeed make a direct function call, which is faster,
given IPv4 is built-in in the networking code by default. Still,
CONFIG_INET=n and CONFIG_NETFILTER=y is possible, so define empty inline
stub for IPv4 in such case.

Signed-off-by: Pablo Neira Ayuso