kernel/linux.git/include/linux/netfilter.h, branch v4.19.310

Remove DECnet support from kernel

2023-06-21T13:39:57+00:00

commit 1202cdd665315c525b5237e96e0bedc76d7e754f upstream. DECnet is an obsolete network protocol that receives more attention from kernel janitors than users. It belongs in computer protocol history museum not in Linux kernel. It has been "Orphaned" in kernel since 2010. The iproute2 support for DECnet was dropped in 5.0 release. The documentation link on Sourceforge says it is abandoned there as well. Leave the UAPI alone to keep userspace programs compiling. This means that there is still an empty neighbour table for AF_DECNET. The table of /proc/sys/net entries was updated to match current directories and reformatted to be alphabetical. Signed-off-by: Stephen Hemminger Acked-by: David Ahern Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

netfilter: clear skb->next in NF_HOOK_LIST()

2020-12-02T07:48:07+00:00

NF_HOOK_LIST() uses list_del() to remove skb from the linked list, however, it is not sufficient as skb->next still points to other skb. We should just call skb_list_del_init() to clear skb->next, like the rest places which using skb list. This has been fixed in upstream by commit ca58fbe06c54 ("netfilter: add and use nf_hook_slow_list()"). Fixes: 9f17dbf04ddf ("netfilter: fix use-after-free in NF_HOOK_LIST") Reported-by: liuzx@knownsec.com Tested-by: liuzx@knownsec.com Cc: Florian Westphal Cc: Edward Cree Cc: stable@vger.kernel.org # between 4.19 and 5.4 Signed-off-by: Cong Wang Signed-off-by: Greg Kroah-Hartman

jump_label: move 'asm goto' support test to Kconfig

2019-06-04T06:02:34+00:00

commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream. Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label". The jump label is controlled by HAVE_JUMP_LABEL, which is defined like this: #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) # define HAVE_JUMP_LABEL #endif We can improve this by testing 'asm goto' support in Kconfig, then make JUMP_LABEL depend on CC_HAS_ASM_GOTO. Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will match to the real kernel capability. Signed-off-by: Masahiro Yamada Acked-by: Michael Ellerman (powerpc) Tested-by: Sedat Dilek [nc: Fix trivial conflicts in 4.19 arch/xtensa/kernel/jump_label.c doesn't exist yet Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently eliminated] Signed-off-by: Nathan Chancellor Signed-off-by: Greg Kroah-Hartman

netfilter: avoid erronous array bounds warning

2018-09-28T12:47:40+00:00

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

netfilter: Add nf_ct_get_tuple_skb global lookup function

2018-07-11T03:06:34+00:00

This adds a global netfilter function to extract a conntrack tuple from an skb. The function uses a new function added to nf_ct_hook, which will try to get the tuple from skb->_nfct, and do a full lookup if that fails. This makes it possible to use the lookup function before the skb has passed through the conntrack init hooks (e.g., in an ingress qdisc). The tuple is copied to the caller to avoid issues with reference counting. The function returns false if conntrack is not loaded, allowing it to be used without incurring a module dependency on conntrack. This is used by the NAT mode in sch_cake. Cc: netfilter-devel@vger.kernel.org Signed-off-by: Toke Høiland-Jørgensen Signed-off-by: David S. Miller

netfilter: fix use-after-free in NF_HOOK_LIST

2018-07-09T21:55:53+00:00

nf_hook() can free the skb, so we need to remove it from the list before calling, and add passed skbs to a sublist afterwards. Fixes: 17266ee93984 ("net: ipv4: listified version of ip_rcv") Reported-by: Dan Carpenter Signed-off-by: Edward Cree Signed-off-by: David S. Miller

net: ipv4: listified version of ip_rcv

2018-07-04T05:06:20+00:00

Also involved adding a way to run a netfilter hook over a list of packets. Rather than attempting to make netfilter know about lists (which would be a major project in itself) we just let it call the regular okfn (in this case ip_rcv_finish()) for any packets it steals, and have it give us back a list of packets it's synchronously accepted (which normally NF_HOOK would automatically call okfn() on, but we want to be able to potentially pass the list to a listified version of okfn().) The netfilter hooks themselves are indirect calls that still happen per- packet (see nf_hook_entry_hookfn()), but again, changing that can be left for future work. There is potential for out-of-order receives if the netfilter hook ends up synchronously stealing packets, as they will be processed before any accepts earlier in the list. However, it was already possible for an asynchronous accept to cause out-of-order receives, so presumably this is considered OK. Signed-off-by: Edward Cree Signed-off-by: David S. Miller

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