Commit Graph

6698 Commits

Author SHA1 Message Date
Florian Westphal
90cdd7e5a4 nft_set_pipapo: fix incorrect avx2 match of 5th field octet
[ Upstream commit e042ed950d4e176379ba4c0722146cd96fb38aa2 ]

Given a set element like:

	icmpv6 . dead:beef:00ff::1

The value of 'ff' is irrelevant, any address will be matched
as long as the other octets are the same.

This is because of too-early register clobbering:
ymm7 is reloaded with new packet data (pkt[9])  but it still holds data
of an earlier load that wasn't processed yet.

The existing tests in nft_concat_range.sh selftests do exercise this code
path, but do not trigger incorrect matching due to the network prefix
limitation.

Fixes: 7400b06396 ("nft_set_pipapo: Introduce AVX2-based lookup implementation")
Reported-by: sontu mazumdar <sontu21@gmail.com>
Closes: https://lore.kernel.org/netfilter/CANgxkqwnMH7fXra+VUfODT-8+qFLgskq3set1cAzqqJaV4iEZg@mail.gmail.com/T/#t
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-25 10:45:09 +02:00
Lin Ma
5a2976cc4d net: fix geneve_opt length integer overflow
[ Upstream commit b27055a08ad4b415dcf15b63034f9cb236f7fb40 ]

struct geneve_opt uses 5 bit length for each single option, which
means every vary size option should be smaller than 128 bytes.

However, all current related Netlink policies cannot promise this
length condition and the attacker can exploit a exact 128-byte size
option to *fake* a zero length option and confuse the parsing logic,
further achieve heap out-of-bounds read.

One example crash log is like below:

[    3.905425] ==================================================================
[    3.905925] BUG: KASAN: slab-out-of-bounds in nla_put+0xa9/0xe0
[    3.906255] Read of size 124 at addr ffff888005f291cc by task poc/177
[    3.906646]
[    3.906775] CPU: 0 PID: 177 Comm: poc-oob-read Not tainted 6.1.132 #1
[    3.907131] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[    3.907784] Call Trace:
[    3.907925]  <TASK>
[    3.908048]  dump_stack_lvl+0x44/0x5c
[    3.908258]  print_report+0x184/0x4be
[    3.909151]  kasan_report+0xc5/0x100
[    3.909539]  kasan_check_range+0xf3/0x1a0
[    3.909794]  memcpy+0x1f/0x60
[    3.909968]  nla_put+0xa9/0xe0
[    3.910147]  tunnel_key_dump+0x945/0xba0
[    3.911536]  tcf_action_dump_1+0x1c1/0x340
[    3.912436]  tcf_action_dump+0x101/0x180
[    3.912689]  tcf_exts_dump+0x164/0x1e0
[    3.912905]  fw_dump+0x18b/0x2d0
[    3.913483]  tcf_fill_node+0x2ee/0x460
[    3.914778]  tfilter_notify+0xf4/0x180
[    3.915208]  tc_new_tfilter+0xd51/0x10d0
[    3.918615]  rtnetlink_rcv_msg+0x4a2/0x560
[    3.919118]  netlink_rcv_skb+0xcd/0x200
[    3.919787]  netlink_unicast+0x395/0x530
[    3.921032]  netlink_sendmsg+0x3d0/0x6d0
[    3.921987]  __sock_sendmsg+0x99/0xa0
[    3.922220]  __sys_sendto+0x1b7/0x240
[    3.922682]  __x64_sys_sendto+0x72/0x90
[    3.922906]  do_syscall_64+0x5e/0x90
[    3.923814]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[    3.924122] RIP: 0033:0x7e83eab84407
[    3.924331] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf
[    3.925330] RSP: 002b:00007ffff505e370 EFLAGS: 00000202 ORIG_RAX: 000000000000002c
[    3.925752] RAX: ffffffffffffffda RBX: 00007e83eaafa740 RCX: 00007e83eab84407
[    3.926173] RDX: 00000000000001a8 RSI: 00007ffff505e3c0 RDI: 0000000000000003
[    3.926587] RBP: 00007ffff505f460 R08: 00007e83eace1000 R09: 000000000000000c
[    3.926977] R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffff505f3c0
[    3.927367] R13: 00007ffff505f5c8 R14: 00007e83ead1b000 R15: 00005d4fbbe6dcb8

Fix these issues by enforing correct length condition in related
policies.

Fixes: 925d844696 ("netfilter: nft_tunnel: add support for geneve opts")
Fixes: 4ece477870 ("lwtunnel: add options setting and dumping for geneve")
Fixes: 0ed5269f9e ("net/sched: add tunnel option support to act_tunnel_key")
Fixes: 0a6e77784f ("net/sched: allow flower to match tunnel options")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://patch.msgid.link/20250402165632.6958-1-linma@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10 14:37:40 +02:00
Lin Ma
28d88ee1e1 netfilter: nft_tunnel: fix geneve_opt type confusion addition
[ Upstream commit 1b755d8eb1ace3870789d48fbd94f386ad6e30be ]

When handling multiple NFTA_TUNNEL_KEY_OPTS_GENEVE attributes, the
parsing logic should place every geneve_opt structure one by one
compactly. Hence, when deciding the next geneve_opt position, the
pointer addition should be in units of char *.

However, the current implementation erroneously does type conversion
before the addition, which will lead to heap out-of-bounds write.

[    6.989857] ==================================================================
[    6.990293] BUG: KASAN: slab-out-of-bounds in nft_tunnel_obj_init+0x977/0xa70
[    6.990725] Write of size 124 at addr ffff888005f18974 by task poc/178
[    6.991162]
[    6.991259] CPU: 0 PID: 178 Comm: poc-oob-write Not tainted 6.1.132 #1
[    6.991655] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
[    6.992281] Call Trace:
[    6.992423]  <TASK>
[    6.992586]  dump_stack_lvl+0x44/0x5c
[    6.992801]  print_report+0x184/0x4be
[    6.993790]  kasan_report+0xc5/0x100
[    6.994252]  kasan_check_range+0xf3/0x1a0
[    6.994486]  memcpy+0x38/0x60
[    6.994692]  nft_tunnel_obj_init+0x977/0xa70
[    6.995677]  nft_obj_init+0x10c/0x1b0
[    6.995891]  nf_tables_newobj+0x585/0x950
[    6.996922]  nfnetlink_rcv_batch+0xdf9/0x1020
[    6.998997]  nfnetlink_rcv+0x1df/0x220
[    6.999537]  netlink_unicast+0x395/0x530
[    7.000771]  netlink_sendmsg+0x3d0/0x6d0
[    7.001462]  __sock_sendmsg+0x99/0xa0
[    7.001707]  ____sys_sendmsg+0x409/0x450
[    7.002391]  ___sys_sendmsg+0xfd/0x170
[    7.003145]  __sys_sendmsg+0xea/0x170
[    7.004359]  do_syscall_64+0x5e/0x90
[    7.005817]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[    7.006127] RIP: 0033:0x7ec756d4e407
[    7.006339] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf
[    7.007364] RSP: 002b:00007ffed5d46760 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[    7.007827] RAX: ffffffffffffffda RBX: 00007ec756cc4740 RCX: 00007ec756d4e407
[    7.008223] RDX: 0000000000000000 RSI: 00007ffed5d467f0 RDI: 0000000000000003
[    7.008620] RBP: 00007ffed5d468a0 R08: 0000000000000000 R09: 0000000000000000
[    7.009039] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
[    7.009429] R13: 00007ffed5d478b0 R14: 00007ec756ee5000 R15: 00005cbd4e655cb8

Fix this bug with correct pointer addition and conversion in parse
and dump code.

Fixes: 925d844696 ("netfilter: nft_tunnel: add support for geneve opts")
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10 14:37:40 +02:00
Florian Westphal
6134d1ea1e netfilter: nf_tables: don't unregister hook when table is dormant
[ Upstream commit 688c15017d5cd5aac882400782e7213d40dc3556 ]

When nf_tables_updchain encounters an error, hook registration needs to
be rolled back.

This should only be done if the hook has been registered, which won't
happen when the table is flagged as dormant (inactive).

Just move the assignment into the registration block.

Reported-by: syzbot+53ed3a6440173ddbf499@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=53ed3a6440173ddbf499
Fixes: b9703ed44f ("netfilter: nf_tables: support for adding new devices to an existing netdev chain")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10 14:37:39 +02:00
Pablo Neira Ayuso
073b04796c netfilter: nft_set_hash: GC reaps elements with conncount for dynamic sets only
[ Upstream commit 9d74da1177c800eb3d51c13f9821b7b0683845a5 ]

conncount has its own GC handler which determines when to reap stale
elements, this is convenient for dynamic sets. However, this also reaps
non-dynamic sets with static configurations coming from control plane.
Always run connlimit gc handler but honor feedback to reap element if
this set is dynamic.

Fixes: 290180e244 ("netfilter: nf_tables: add connlimit support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-04-10 14:37:39 +02:00
Sebastian Andrzej Siewior
fa81cb19f5 netfilter: nft_counter: Use u64_stats_t for statistic.
commit 4a1d3acd6ea86075e77fcc1188c3fc372833ba73 upstream.

The nft_counter uses two s64 counters for statistics. Those two are
protected by a seqcount to ensure that the 64bit variable is always
properly seen during updates even on 32bit architectures where the store
is performed by two writes. A side effect is that the two counter (bytes
and packet) are written and read together in the same window.

This can be replaced with u64_stats_t. write_seqcount_begin()/ end() is
replaced with u64_stats_update_begin()/ end() and behaves the same way
as with seqcount_t on 32bit architectures. Additionally there is a
preempt_disable on PREEMPT_RT to ensure that a reader does not preempt a
writer.
On 64bit architectures the macros are removed and the reads happen
without any retries. This also means that the reader can observe one
counter (bytes) from before the update and the other counter (packets)
but that is okay since there is no requirement to have both counter from
the same update window.

Convert the statistic to u64_stats_t. There is one optimisation:
nft_counter_do_init() and nft_counter_clone() allocate a new per-CPU
counter and assign a value to it. During this assignment preemption is
disabled which is not needed because the counter is not yet exposed to
the system so there can not be another writer or reader. Therefore
disabling preemption is omitted and raw_cpu_ptr() is used to obtain a
pointer to a counter for the assignment.

Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-28 21:59:57 +01:00
Florian Westphal
a561c6a034 netfilter: nf_tables: allow clone callbacks to sleep
commit fa23e0d4b756d25829e124d6b670a4c6bbd4bf7e upstream.

Sven Auhagen reports transaction failures with following error:
  ./main.nft:13:1-26: Error: Could not process rule: Cannot allocate memory
  percpu: allocation failed, size=16 align=8 atomic=1, atomic alloc failed, no space left

This points to failing pcpu allocation with GFP_ATOMIC flag.
However, transactions happen from user context and are allowed to sleep.

One case where we can call into percpu allocator with GFP_ATOMIC is
nft_counter expression.

Normally this happens from control plane, so this could use GFP_KERNEL
instead.  But one use case, element insertion from packet path,
needs to use GFP_ATOMIC allocations (nft_dynset expression).

At this time, .clone callbacks always use GFP_ATOMIC for this reason.

Add gfp_t argument to the .clone function and pass GFP_KERNEL or
GFP_ATOMIC flag depending on context, this allows all clone memory
allocations to sleep for the normal (transaction) case.

Cc: Sven Auhagen <sven.auhagen@voleatech.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-22 12:50:50 -07:00
Pablo Neira Ayuso
f6de68e154 netfilter: nf_tables: bail out if stateful expression provides no .clone
commit 3c13725f43dcf43ad8a9bcd6a9f12add19a8f93e upstream.

All existing NFT_EXPR_STATEFUL provide a .clone interface, remove
fallback to copy content of stateful expression since this is never
exercised and bail out if .clone interface is not defined.

Stable-dep-of: fa23e0d4b756 ("netfilter: nf_tables: allow clone callbacks to sleep")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-22 12:50:50 -07:00
Pablo Neira Ayuso
7fa2e2960f netfilter: nf_tables: use timestamp to check for set element timeout
commit 7395dfacfff65e9938ac0889dafa1ab01e987d15 upstream.

Add a timestamp field at the beginning of the transaction, store it
in the nftables per-netns area.

Update set backend .insert, .deactivate and sync gc path to use the
timestamp, this avoids that an element expires while control plane
transaction is still unfinished.

.lookup and .update, which are used from packet path, still use the
current time to check if the element has expired. And .get path and dump
also since this runs lockless under rcu read size lock. Then, there is
async gc which also needs to check the current time since it runs
asynchronously from a workqueue.

Fixes: c3e1b005ed ("netfilter: nf_tables: add set element timeout support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Jianqi Ren <jianqi.ren.cn@windriver.com>
Signed-off-by: He Zhe <zhe.he@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-22 12:50:50 -07:00
Alexey Kashavkin
181b68fa55 netfilter: nft_exthdr: fix offset with ipv4_find_option()
[ Upstream commit 6edd78af9506bb182518da7f6feebd75655d9a0e ]

There is an incorrect calculation in the offset variable which causes
the nft_skb_copy_to_reg() function to always return -EFAULT. Adding the
start variable is redundant. In the __ip_options_compile() function the
correct offset is specified when finding the function. There is no need
to add the size of the iphdr structure to the offset.

Fixes: dbb5281a1f ("netfilter: nf_tables: add support for matching IPv4 options")
Signed-off-by: Alexey Kashavkin <akashavkin@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-22 12:50:39 -07:00
Dan Carpenter
1bd2a8bb1c ipvs: prevent integer overflow in do_ip_vs_get_ctl()
[ Upstream commit 80b78c39eb86e6b55f56363b709eb817527da5aa ]

The get->num_services variable is an unsigned int which is controlled by
the user.  The struct_size() function ensures that the size calculation
does not overflow an unsigned long, however, we are saving the result to
an int so the calculation can overflow.

Both "len" and "get->num_services" come from the user.  This check is
just a sanity check to help the user and ensure they are using the API
correctly.  An integer overflow here is not a big deal.  This has no
security impact.

Save the result from struct_size() type size_t to fix this integer
overflow bug.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-22 12:50:39 -07:00
Kohei Enju
fda50302a1 netfilter: nf_conncount: Fully initialize struct nf_conncount_tuple in insert_tree()
[ Upstream commit d653bfeb07ebb3499c403404c21ac58a16531607 ]

Since commit b36e4523d4 ("netfilter: nf_conncount: fix garbage
collection confirm race"), `cpu` and `jiffies32` were introduced to
the struct nf_conncount_tuple.

The commit made nf_conncount_add() initialize `conn->cpu` and
`conn->jiffies32` when allocating the struct.
In contrast, count_tree() was not changed to initialize them.

By commit 34848d5c89 ("netfilter: nf_conncount: Split insert and
traversal"), count_tree() was split and the relevant allocation
code now resides in insert_tree().
Initialize `conn->cpu` and `conn->jiffies32` in insert_tree().

BUG: KMSAN: uninit-value in find_or_evict net/netfilter/nf_conncount.c:117 [inline]
BUG: KMSAN: uninit-value in __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143
 find_or_evict net/netfilter/nf_conncount.c:117 [inline]
 __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143
 count_tree net/netfilter/nf_conncount.c:438 [inline]
 nf_conncount_count+0x82f/0x1e80 net/netfilter/nf_conncount.c:521
 connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72
 __nft_match_eval net/netfilter/nft_compat.c:403 [inline]
 nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433
 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
 nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288
 nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
 nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663
 NF_HOOK_LIST include/linux/netfilter.h:350 [inline]
 ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633
 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:669
 __netif_receive_skb_list_ptype net/core/dev.c:5936 [inline]
 __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5983
 __netif_receive_skb_list net/core/dev.c:6035 [inline]
 netif_receive_skb_list_internal+0x1085/0x1700 net/core/dev.c:6126
 netif_receive_skb_list+0x5a/0x460 net/core/dev.c:6178
 xdp_recv_frames net/bpf/test_run.c:280 [inline]
 xdp_test_run_batch net/bpf/test_run.c:361 [inline]
 bpf_test_run_xdp_live+0x2e86/0x3480 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0xf1d/0x1ae0 net/bpf/test_run.c:1316
 bpf_prog_test_run+0x5e5/0xa30 kernel/bpf/syscall.c:4407
 __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5813
 __do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
 __ia32_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5900
 ia32_sys_call+0x394d/0x4180 arch/x86/include/generated/asm/syscalls_32.h:358
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:387
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:412
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:450
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4121 [inline]
 slab_alloc_node mm/slub.c:4164 [inline]
 kmem_cache_alloc_noprof+0x915/0xe10 mm/slub.c:4171
 insert_tree net/netfilter/nf_conncount.c:372 [inline]
 count_tree net/netfilter/nf_conncount.c:450 [inline]
 nf_conncount_count+0x1415/0x1e80 net/netfilter/nf_conncount.c:521
 connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72
 __nft_match_eval net/netfilter/nft_compat.c:403 [inline]
 nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433
 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
 nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288
 nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
 nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663
 NF_HOOK_LIST include/linux/netfilter.h:350 [inline]
 ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633
 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:669
 __netif_receive_skb_list_ptype net/core/dev.c:5936 [inline]
 __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5983
 __netif_receive_skb_list net/core/dev.c:6035 [inline]
 netif_receive_skb_list_internal+0x1085/0x1700 net/core/dev.c:6126
 netif_receive_skb_list+0x5a/0x460 net/core/dev.c:6178
 xdp_recv_frames net/bpf/test_run.c:280 [inline]
 xdp_test_run_batch net/bpf/test_run.c:361 [inline]
 bpf_test_run_xdp_live+0x2e86/0x3480 net/bpf/test_run.c:390
 bpf_prog_test_run_xdp+0xf1d/0x1ae0 net/bpf/test_run.c:1316
 bpf_prog_test_run+0x5e5/0xa30 kernel/bpf/syscall.c:4407
 __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5813
 __do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
 __ia32_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5900
 ia32_sys_call+0x394d/0x4180 arch/x86/include/generated/asm/syscalls_32.h:358
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:387
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:412
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:450
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Reported-by: syzbot+83fed965338b573115f7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=83fed965338b573115f7
Fixes: b36e4523d4 ("netfilter: nf_conncount: fix garbage collection confirm race")
Signed-off-by: Kohei Enju <enjuk@amazon.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-22 12:50:39 -07:00
Nicklas Bo Jensen
0a9f0cfd2a netfilter: nf_conncount: garbage collection is not skipped when jiffies wrap around
[ Upstream commit df08c94baafb001de6cf44bb7098bb557f36c335 ]

nf_conncount is supposed to skip garbage collection if it has already
run garbage collection in the same jiffy. Unfortunately, this is broken
when jiffies wrap around which this patch fixes.

The problem is that last_gc in the nf_conncount_list struct is an u32,
but jiffies is an unsigned long which is 8 bytes on my systems. When
those two are compared it only works until last_gc wraps around.

See bug report: https://bugzilla.netfilter.org/show_bug.cgi?id=1778
for more details.

Fixes: d265929930 ("netfilter: nf_conncount: reduce unnecessary GC")
Signed-off-by: Nicklas Bo Jensen <njensen@akamai.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-22 12:50:38 -07:00
Sebastian Andrzej Siewior
29bde9751c netfilter: nft_ct: Use __refcount_inc() for per-CPU nft_ct_pcpu_template.
[ Upstream commit 5cfe5612ca9590db69b9be29dc83041dbf001108 ]

nft_ct_pcpu_template is a per-CPU variable and relies on disabled BH for its
locking. The refcounter is read and if its value is set to one then the
refcounter is incremented and variable is used - otherwise it is already
in use and left untouched.

Without per-CPU locking in local_bh_disable() on PREEMPT_RT the
read-then-increment operation is not atomic and therefore racy.

This can be avoided by using unconditionally __refcount_inc() which will
increment counter and return the old value as an atomic operation.
In case the returned counter is not one, the variable is in use and we
need to decrement counter. Otherwise we can use it.

Use __refcount_inc() instead of read and a conditional increment.

Fixes: edee4f1e92 ("netfilter: nft_ct: add zone id set support")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-03-22 12:50:37 -07:00
Pablo Neira Ayuso
82e491e085 netfilter: nf_tables: reject mismatching sum of field_len with set key length
commit 1b9335a8000fb70742f7db10af314104b6ace220 upstream.

The field length description provides the length of each separated key
field in the concatenation, each field gets rounded up to 32-bits to
calculate the pipapo rule width from pipapo_init(). The set key length
provides the total size of the key aligned to 32-bits.

Register-based arithmetics still allows for combining mismatching set
key length and field length description, eg. set key length 10 and field
description [ 5, 4 ] leading to pipapo width of 12.

Cc: stable@vger.kernel.org
Fixes: 3ce67e3793f4 ("netfilter: nf_tables: do not allow mismatch field size and set key length")
Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-08 09:52:35 +01:00
Florian Westphal
e3c1a0e4ba netfilter: nft_flow_offload: update tcp state flags under lock
[ Upstream commit 7a4b61406395291ffb7220a10e8951a9a8684819 ]

The conntrack entry is already public, there is a small chance that another
CPU is handling a packet in reply direction and racing with the tcp state
update.

Move this under ct spinlock.

This is done once, when ct is about to be offloaded, so this should
not result in a noticeable performance hit.

Fixes: 8437a6209f ("netfilter: nft_flow_offload: set liberal tracking mode for tcp")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:03 +01:00
Pablo Neira Ayuso
d9aaae892d netfilter: nf_tables: fix set size with rbtree backend
[ Upstream commit 8d738c1869f611955d91d8d0fd0012d9ef207201 ]

The existing rbtree implementation uses singleton elements to represent
ranges, however, userspace provides a set size according to the number
of ranges in the set.

Adjust provided userspace set size to the number of singleton elements
in the kernel by multiplying the range by two.

Check if the no-match all-zero element is already in the set, in such
case release one slot in the set size.

Fixes: 0ed6389c48 ("netfilter: nf_tables: rename set implementations")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:03 +01:00
Florian Westphal
c80fcb6caa netfilter: nft_set_rbtree: prefer sync gc to async worker
[ Upstream commit 7d259f021aaa78904b6c836d975e8e00d83a182a ]

There is no need for asynchronous garbage collection, rbtree inserts
can only happen from the netlink control plane.

We already perform on-demand gc on insertion, in the area of the
tree where the insertion takes place, but we don't do a full tree
walk there for performance reasons.

Do a full gc walk at the end of the transaction instead and
remove the async worker.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 8d738c1869f6 ("netfilter: nf_tables: fix set size with rbtree backend")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:03 +01:00
Florian Westphal
b7e81ae386 netfilter: nft_set_rbtree: rename gc deactivate+erase function
[ Upstream commit 8079fc30f79799e59d9602e7e080d434936a482d ]

Next patch adds a cllaer that doesn't hold the priv->write lock and
will need a similar function.

Rename the existing function to make it clear that it can only
be used for opportunistic gc during insertion.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 8d738c1869f6 ("netfilter: nf_tables: fix set size with rbtree backend")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:03 +01:00
Florian Westphal
6f8277b97a netfilter: nf_tables: de-constify set commit ops function argument
[ Upstream commit 256001672153af5786c6ca148114693d7d76d836 ]

The set backend using this already has to work around this via ugly
cast, don't spread this pattern.

Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: 8d738c1869f6 ("netfilter: nf_tables: fix set size with rbtree backend")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-02-08 09:52:03 +01:00
Pablo Neira Ayuso
d5807dd132 netfilter: conntrack: clamp maximum hashtable size to INT_MAX
[ Upstream commit b541ba7d1f5a5b7b3e2e22dc9e40e18a7d6dbc13 ]

Use INT_MAX as maximum size for the conntrack hashtable. Otherwise, it
is possible to hit WARN_ON_ONCE in __kvmalloc_node_noprof() when
resizing hashtable because __GFP_NOWARN is unset. See:

  0708a0afe2 ("mm: Consider __GFP_NOWARN flag for oversized kvmalloc() calls")

Note: hashtable resize is only possible from init_netns.

Fixes: 9cc1c73ad6 ("netfilter: conntrack: avoid integer overflow when resizing")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-17 13:36:15 +01:00
Pablo Neira Ayuso
1e3f5638c9 netfilter: nf_tables: imbalance in flowtable binding
[ Upstream commit 13210fc63f353fe78584048079343413a3cdf819 ]

All these cases cause imbalance between BIND and UNBIND calls:

- Delete an interface from a flowtable with multiple interfaces

- Add a (device to a) flowtable with --check flag

- Delete a netns containing a flowtable

- In an interactive nft session, create a table with owner flag and
  flowtable inside, then quit.

Fix it by calling FLOW_BLOCK_UNBIND when unregistering hooks, then
remove late FLOW_BLOCK_UNBIND call when destroying flowtable.

Fixes: ff4bf2f42a ("netfilter: nf_tables: add nft_unregister_flowtable_hook()")
Reported-by: Phil Sutter <phil@nwl.cc>
Tested-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-01-17 13:36:15 +01:00
Phil Sutter
576b58f39b netfilter: ipset: Fix for recursive locking warning
[ Upstream commit 70b6f46a4ed8bd56c85ffff22df91e20e8c85e33 ]

With CONFIG_PROVE_LOCKING, when creating a set of type bitmap:ip, adding
it to a set of type list:set and populating it from iptables SET target
triggers a kernel warning:

| WARNING: possible recursive locking detected
| 6.12.0-rc7-01692-g5e9a28f41134-dirty #594 Not tainted
| --------------------------------------------
| ping/4018 is trying to acquire lock:
| ffff8881094a6848 (&set->lock){+.-.}-{2:2}, at: ip_set_add+0x28c/0x360 [ip_set]
|
| but task is already holding lock:
| ffff88811034c048 (&set->lock){+.-.}-{2:2}, at: ip_set_add+0x28c/0x360 [ip_set]

This is a false alarm: ipset does not allow nested list:set type, so the
loop in list_set_kadd() can never encounter the outer set itself. No
other set type supports embedded sets, so this is the only case to
consider.

To avoid the false report, create a distinct lock class for list:set
type ipset locks.

Fixes: f830837f0e ("netfilter: ipset: list:set set type support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-27 13:58:49 +01:00
David Laight
592fc96af8 ipvs: Fix clamp() of ip_vs_conn_tab on small memory systems
[ Upstream commit cf2c97423a4f89c8b798294d3f34ecfe7e7035c3 ]

The 'max_avail' value is calculated from the system memory
size using order_base_2().
order_base_2(x) is defined as '(x) ? fn(x) : 0'.
The compiler generates two copies of the code that follows
and then expands clamp(max, min, PAGE_SHIFT - 12) (11 on 32bit).
This triggers a compile-time assert since min is 5.

In reality a system would have to have less than 512MB memory
for the bounds passed to clamp to be reversed.

Swap the order of the arguments to clamp() to avoid the warning.

Replace the clamp_val() on the line below with clamp().
clamp_val() is just 'an accident waiting to happen' and not needed here.

Detected by compile time checks added to clamp(), specifically:
minmax.h: use BUILD_BUG_ON_MSG() for the lo < hi test in clamp()

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Closes: https://lore.kernel.org/all/CA+G9fYsT34UkGFKxus63H6UVpYi5GRZkezT9MRLfAbM3f6ke0g@mail.gmail.com/
Fixes: 4f325e2627 ("ipvs: dynamically limit the connection hash table")
Tested-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Signed-off-by: David Laight <david.laight@aculab.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-27 13:58:49 +01:00
Florian Westphal
27f0574253 netfilter: nf_tables: do not defer rule destruction via call_rcu
[ Upstream commit b04df3da1b5c6f6dc7cdccc37941740c078c4043 ]

nf_tables_chain_destroy can sleep, it can't be used from call_rcu
callbacks.

Moreover, nf_tables_rule_release() is only safe for error unwinding,
while transaction mutex is held and the to-be-desroyed rule was not
exposed to either dataplane or dumps, as it deactives+frees without
the required synchronize_rcu() in-between.

nft_rule_expr_deactivate() callbacks will change ->use counters
of other chains/sets, see e.g. nft_lookup .deactivate callback, these
must be serialized via transaction mutex.

Also add a few lockdep asserts to make this more explicit.

Calling synchronize_rcu() isn't ideal, but fixing this without is hard
and way more intrusive.  As-is, we can get:

WARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x..
Workqueue: events nf_tables_trans_destroy_work
RIP: 0010:nft_set_destroy+0x3fe/0x5c0
Call Trace:
 <TASK>
 nf_tables_trans_destroy_work+0x6b7/0xad0
 process_one_work+0x64a/0xce0
 worker_thread+0x613/0x10d0

In case the synchronize_rcu becomes an issue, we can explore alternatives.

One way would be to allocate nft_trans_rule objects + one nft_trans_chain
object, deactivate the rules + the chain and then defer the freeing to the
nft destroy workqueue.  We'd still need to keep the synchronize_rcu path as
a fallback to handle -ENOMEM corner cases though.

Reported-by: syzbot+b26935466701e56cfdc2@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/67478d92.050a0220.253251.0062.GAE@google.com/T/
Fixes: c03d278fdf35 ("netfilter: nf_tables: wait for rcu grace period on net_device removal")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-19 18:11:32 +01:00
Phil Sutter
8c2c8445cd netfilter: IDLETIMER: Fix for possible ABBA deadlock
[ Upstream commit f36b01994d68ffc253c8296e2228dfe6e6431c03 ]

Deletion of the last rule referencing a given idletimer may happen at
the same time as a read of its file in sysfs:

| ======================================================
| WARNING: possible circular locking dependency detected
| 6.12.0-rc7-01692-g5e9a28f41134-dirty #594 Not tainted
| ------------------------------------------------------
| iptables/3303 is trying to acquire lock:
| ffff8881057e04b8 (kn->active#48){++++}-{0:0}, at: __kernfs_remove+0x20
|
| but task is already holding lock:
| ffffffffa0249068 (list_mutex){+.+.}-{3:3}, at: idletimer_tg_destroy_v]
|
| which lock already depends on the new lock.

A simple reproducer is:

| #!/bin/bash
|
| while true; do
|         iptables -A INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
|         iptables -D INPUT -i foo -j IDLETIMER --timeout 10 --label "testme"
| done &
| while true; do
|         cat /sys/class/xt_idletimer/timers/testme >/dev/null
| done

Avoid this by freeing list_mutex right after deleting the element from
the list, then continuing with the teardown.

Fixes: 0902b469bd ("netfilter: xtables: idletimer target implementation")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-19 18:11:32 +01:00
Pablo Neira Ayuso
86c2760351 netfilter: nft_set_hash: skip duplicated elements pending gc run
[ Upstream commit 7ffc7481153bbabf3332c6a19b289730c7e1edf5 ]

rhashtable does not provide stable walk, duplicated elements are
possible in case of resizing. I considered that checking for errors when
calling rhashtable_walk_next() was sufficient to detect the resizing.
However, rhashtable_walk_next() returns -EAGAIN only at the end of the
iteration, which is too late, because a gc work containing duplicated
elements could have been already scheduled for removal to the worker.

Add a u32 gc worker sequence number per set, bump it on every workqueue
run. Annotate gc worker sequence number on the expired element. Use it
to skip those already seen in this gc workqueue run.

Note that this new field is never reset in case gc transaction fails, so
next gc worker run on the expired element overrides it. Wraparound of gc
worker sequence number should not be an issue with stale gc worker
sequence number in the element, that would just postpone the element
removal in one gc run.

Note that it is not possible to use flags to annotate that element is
pending gc run to detect duplicates, given that gc transaction can be
invalidated in case of update from the control plane, therefore, not
allowing to clear such flag.

On x86_64, pahole reports no changes in the size of nft_rhash_elem.

Fixes: f6c383b8c3 ("netfilter: nf_tables: adapt set backend to use GC transaction API")
Reported-by: Laurent Fasnacht <laurent.fasnacht@proton.ch>
Tested-by: Laurent Fasnacht <laurent.fasnacht@proton.ch>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:59:38 +01:00
Phil Sutter
90bf312a6b netfilter: ipset: Hold module reference while requesting a module
[ Upstream commit 456f010bfaefde84d3390c755eedb1b0a5857c3c ]

User space may unload ip_set.ko while it is itself requesting a set type
backend module, leading to a kernel crash. The race condition may be
provoked by inserting an mdelay() right after the nfnl_unlock() call.

Fixes: a7b4f989a6 ("netfilter: ipset: IP set core support")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Acked-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:59:38 +01:00
Pablo Neira Ayuso
53c7314208 netfilter: nft_inner: incorrect percpu area handling under softirq
[ Upstream commit 7b1d83da254be3bf054965c8f3b1ad976f460ae5 ]

Softirq can interrupt ongoing packet from process context that is
walking over the percpu area that contains inner header offsets.

Disable bh and perform three checks before restoring the percpu inner
header offsets to validate that the percpu area is valid for this
skbuff:

1) If the NFT_PKTINFO_INNER_FULL flag is set on, then this skbuff
   has already been parsed before for inner header fetching to
   register.

2) Validate that the percpu area refers to this skbuff using the
   skbuff pointer as a cookie. If there is a cookie mismatch, then
   this skbuff needs to be parsed again.

3) Finally, validate if the percpu area refers to this tunnel type.

Only after these three checks the percpu area is restored to a on-stack
copy and bh is enabled again.

After inner header fetching, the on-stack copy is stored back to the
percpu area.

Fixes: 3a07327d10 ("netfilter: nft_inner: support for inner tunnel header matching")
Reported-by: syzbot+84d0441b9860f0d63285@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:59:38 +01:00
Eric Dumazet
797a4c1f5b ipv6: introduce dst_rt6_info() helper
[ Upstream commit e8dfd42c17faf183415323db1ef0c977be0d6489 ]

Instead of (struct rt6_info *)dst casts, we can use :

 #define dst_rt6_info(_ptr) \
         container_of_const(_ptr, struct rt6_info, dst)

Some places needed missing const qualifiers :

ip6_confirm_neigh(), ipv6_anycast_destination(),
ipv6_unicast_destination(), has_gateway()

v2: added missing parts (David Ahern)

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 3301ab7d5aeb ("net/ipv6: release expired exception dst cached in socket")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:59:35 +01:00
Pablo Neira Ayuso
2f9bec0a74 netfilter: nft_socket: remove WARN_ON_ONCE on maximum cgroup level
[ Upstream commit b7529880cb961d515642ce63f9d7570869bbbdc3 ]

cgroup maximum depth is INT_MAX by default, there is a cgroup toggle to
restrict this maximum depth to a more reasonable value not to harm
performance. Remove unnecessary WARN_ON_ONCE which is reachable from
userspace.

Fixes: 7f3287db6543 ("netfilter: nft_socket: make cgroupsv2 matching work with namespaces")
Reported-by: syzbot+57bac0866ddd99fe47c0@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:59:34 +01:00
Dmitry Antipov
a9bcc0b70d netfilter: x_tables: fix LED ID check in led_tg_check()
[ Upstream commit 04317f4eb2aad312ad85c1a17ad81fe75f1f9bc7 ]

Syzbot has reported the following BUG detected by KASAN:

BUG: KASAN: slab-out-of-bounds in strlen+0x58/0x70
Read of size 1 at addr ffff8881022da0c8 by task repro/5879
...
Call Trace:
 <TASK>
 dump_stack_lvl+0x241/0x360
 ? __pfx_dump_stack_lvl+0x10/0x10
 ? __pfx__printk+0x10/0x10
 ? _printk+0xd5/0x120
 ? __virt_addr_valid+0x183/0x530
 ? __virt_addr_valid+0x183/0x530
 print_report+0x169/0x550
 ? __virt_addr_valid+0x183/0x530
 ? __virt_addr_valid+0x183/0x530
 ? __virt_addr_valid+0x45f/0x530
 ? __phys_addr+0xba/0x170
 ? strlen+0x58/0x70
 kasan_report+0x143/0x180
 ? strlen+0x58/0x70
 strlen+0x58/0x70
 kstrdup+0x20/0x80
 led_tg_check+0x18b/0x3c0
 xt_check_target+0x3bb/0xa40
 ? __pfx_xt_check_target+0x10/0x10
 ? stack_depot_save_flags+0x6e4/0x830
 ? nft_target_init+0x174/0xc30
 nft_target_init+0x82d/0xc30
 ? __pfx_nft_target_init+0x10/0x10
 ? nf_tables_newrule+0x1609/0x2980
 ? nf_tables_newrule+0x1609/0x2980
 ? rcu_is_watching+0x15/0xb0
 ? nf_tables_newrule+0x1609/0x2980
 ? nf_tables_newrule+0x1609/0x2980
 ? __kmalloc_noprof+0x21a/0x400
 nf_tables_newrule+0x1860/0x2980
 ? __pfx_nf_tables_newrule+0x10/0x10
 ? __nla_parse+0x40/0x60
 nfnetlink_rcv+0x14e5/0x2ab0
 ? __pfx_validate_chain+0x10/0x10
 ? __pfx_nfnetlink_rcv+0x10/0x10
 ? __lock_acquire+0x1384/0x2050
 ? netlink_deliver_tap+0x2e/0x1b0
 ? __pfx_lock_release+0x10/0x10
 ? netlink_deliver_tap+0x2e/0x1b0
 netlink_unicast+0x7f8/0x990
 ? __pfx_netlink_unicast+0x10/0x10
 ? __virt_addr_valid+0x183/0x530
 ? __check_object_size+0x48e/0x900
 netlink_sendmsg+0x8e4/0xcb0
 ? __pfx_netlink_sendmsg+0x10/0x10
 ? aa_sock_msg_perm+0x91/0x160
 ? __pfx_netlink_sendmsg+0x10/0x10
 __sock_sendmsg+0x223/0x270
 ____sys_sendmsg+0x52a/0x7e0
 ? __pfx_____sys_sendmsg+0x10/0x10
 __sys_sendmsg+0x292/0x380
 ? __pfx___sys_sendmsg+0x10/0x10
 ? lockdep_hardirqs_on_prepare+0x43d/0x780
 ? __pfx_lockdep_hardirqs_on_prepare+0x10/0x10
 ? exc_page_fault+0x590/0x8c0
 ? do_syscall_64+0xb6/0x230
 do_syscall_64+0xf3/0x230
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
...
 </TASK>

Since an invalid (without '\0' byte at all) byte sequence may be passed
from userspace, add an extra check to ensure that such a sequence is
rejected as possible ID and so never passed to 'kstrdup()' and further.

Reported-by: syzbot+6c8215822f35fdb35667@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6c8215822f35fdb35667
Fixes: 268cb38e18 ("netfilter: x_tables: add LED trigger target")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:59:33 +01:00
Jinghao Jia
124834133b ipvs: fix UB due to uninitialized stack access in ip_vs_protocol_init()
[ Upstream commit 146b6f1112eb30a19776d6c323c994e9d67790db ]

Under certain kernel configurations when building with Clang/LLVM, the
compiler does not generate a return or jump as the terminator
instruction for ip_vs_protocol_init(), triggering the following objtool
warning during build time:

  vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6()

At runtime, this either causes an oops when trying to load the ipvs
module or a boot-time panic if ipvs is built-in. This same issue has
been reported by the Intel kernel test robot previously.

Digging deeper into both LLVM and the kernel code reveals this to be a
undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer
of 64 chars to store the registered protocol names and leaves it
uninitialized after definition. The function calls strnlen() when
concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE
strnlen() performs an extra step to check whether the last byte of the
input char buffer is a null character (commit 3009f891bb ("fortify:
Allow strlen() and strnlen() to pass compile-time known lengths")).
This, together with possibly other configurations, cause the following
IR to be generated:

  define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 {
    %1 = alloca [64 x i8], align 16
    ...

  14:                                               ; preds = %11
    %15 = getelementptr inbounds i8, ptr %1, i64 63
    %16 = load i8, ptr %15, align 1
    %17 = tail call i1 @llvm.is.constant.i8(i8 %16)
    %18 = icmp eq i8 %16, 0
    %19 = select i1 %17, i1 %18, i1 false
    br i1 %19, label %20, label %23

  20:                                               ; preds = %14
    %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #23
    ...

  23:                                               ; preds = %14, %11, %20
    %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) #24
    ...
  }

The above code calculates the address of the last char in the buffer
(value %15) and then loads from it (value %16). Because the buffer is
never initialized, the LLVM GVN pass marks value %16 as undefined:

  %13 = getelementptr inbounds i8, ptr %1, i64 63
  br i1 undef, label %14, label %17

This gives later passes (SCCP, in particular) more DCE opportunities by
propagating the undef value further, and eventually removes everything
after the load on the uninitialized stack location:

  define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 {
    %1 = alloca [64 x i8], align 16
    ...

  12:                                               ; preds = %11
    %13 = getelementptr inbounds i8, ptr %1, i64 63
    unreachable
  }

In this way, the generated native code will just fall through to the
next function, as LLVM does not generate any code for the unreachable IR
instruction and leaves the function without a terminator.

Zero the on-stack buffer to avoid this possible UB.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/
Co-developed-by: Ruowen Qin <ruqin@redhat.com>
Signed-off-by: Ruowen Qin <ruqin@redhat.com>
Signed-off-by: Jinghao Jia <jinghao7@illinois.edu>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-14 19:59:33 +01:00
Jeongjun Park
856023ef03 netfilter: ipset: add missing range check in bitmap_ip_uadt
commit 35f56c554eb1b56b77b3cf197a6b00922d49033d upstream.

When tb[IPSET_ATTR_IP_TO] is not present but tb[IPSET_ATTR_CIDR] exists,
the values of ip and ip_to are slightly swapped. Therefore, the range check
for ip should be done later, but this part is missing and it seems that the
vulnerability occurs.

So we should add missing range checks and remove unnecessary range checks.

Cc: <stable@vger.kernel.org>
Reported-by: syzbot+58c872f7790a4d2ac951@syzkaller.appspotmail.com
Fixes: 72205fc68b ("netfilter: ipset: bitmap:ip set type support")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Acked-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-09 10:32:47 +01:00
Florian Westphal
c65cff7837 netfilter: nf_tables: must hold rcu read lock while iterating object type list
[ Upstream commit cddc04275f95ca3b18da5c0fb111705ac173af89 ]

Update of stateful object triggers:
WARNING: suspicious RCU usage
net/netfilter/nf_tables_api.c:7759 RCU-list traversed in non-reader section!!

other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by nft/3060:
 #0: ffff88810f0578c8 (&nft_net->commit_mutex){+.+.}-{4:4}, [..]

... but this list is not protected by the transaction mutex but the
nfnl nftables subsystem mutex.

Switch to nft_obj_type_get which will acquire rcu read lock,
bump refcount, and returns the result.

v3: Dan Carpenter points out nft_obj_type_get returns error pointer, not
NULL, on error.

Fixes: dad3bdeef4 ("netfilter: nf_tables: fix memory leak during stateful obj update").
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:32:08 +01:00
Pablo Neira Ayuso
5199d4a4e0 netfilter: nf_tables: skip transaction if update object is not implemented
[ Upstream commit 84b1a0c0140a9a92ea108576c0002210f224ce59 ]

Turn update into noop as a follow up for:

  9fedd894b4 ("netfilter: nf_tables: fix unexpected EOPNOTSUPP error")

instead of adding a transaction object which is simply discarded at a
later stage of the commit protocol.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: cddc04275f95 ("netfilter: nf_tables: must hold rcu read lock while iterating object type list")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:32:08 +01:00
Florian Westphal
981af60dd6 netfilter: nf_tables: must hold rcu read lock while iterating expression type list
[ Upstream commit ee666a541ed957937454d50afa4757924508cd74 ]

nft shell tests trigger:
 WARNING: suspicious RCU usage
 net/netfilter/nf_tables_api.c:3125 RCU-list traversed in non-reader section!!
 1 lock held by nft/2068:
  #0: ffff888106c6f8c8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3c/0xf0

But the transaction mutex doesn't protect this list, the nfnl subsystem
mutex would, but we can't acquire it here without risk of ABBA
deadlocks.

Acquire the rcu read lock to avoid this issue.

v3: add a comment that explains the ->inner_ops check implies
expression is builtin and lack of a module owner reference is ok.

Fixes: 3a07327d10 ("netfilter: nft_inner: support for inner tunnel header matching")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:32:08 +01:00
Florian Westphal
cd38d9cdf4 netfilter: nf_tables: avoid false-positive lockdep splat on rule deletion
[ Upstream commit 9adbb4198bf6cf3634032871118a7052aeaa573f ]

On rule delete we get:
 WARNING: suspicious RCU usage
 net/netfilter/nf_tables_api.c:3420 RCU-list traversed in non-reader section!!
 1 lock held by iptables/134:
   #0: ffff888008c4fcc8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid (include/linux/jiffies.h:101) nf_tables

Code is fine, no other CPU can change the list because we're holding
transaction mutex.

Pass the needed lockdep annotation to the iterator and fix
two comments for functions that are no longer restricted to rcu-only
context.

This is enough to resolve rule delete, but there are several other
missing annotations, added in followup-patches.

Fixes: 28875945ba ("rcu: Add support for consolidated-RCU reader checking")
Reported-by: Matthieu Baerts <matttbe@kernel.org>
Tested-by: Matthieu Baerts <matttbe@kernel.org>
Closes: https://lore.kernel.org/netfilter-devel/da27f17f-3145-47af-ad0f-7fd2a823623e@kernel.org/
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:32:08 +01:00
Phil Sutter
6ee1c9849c netfilter: nf_tables: Introduce nf_tables_getrule_single()
[ Upstream commit 1578c32877191815f631af32ba5dfc1f1b20c1b4 ]

Outsource the reply skb preparation for non-dump getrule requests into a
distinct function. Prep work for rule reset locking.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 9adbb4198bf6 ("netfilter: nf_tables: avoid false-positive lockdep splat on rule deletion")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:32:08 +01:00
Phil Sutter
1d0f811ec1 netfilter: nf_tables: Open-code audit log call in nf_tables_getrule()
[ Upstream commit 8877393029e764036892d39614900987cbd21ca6 ]

The table lookup will be dropped from that function, so remove that
dependency from audit logging code. Using whatever is in
nla[NFTA_RULE_TABLE] is sufficient as long as the previous rule info
filling succeded.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: 9adbb4198bf6 ("netfilter: nf_tables: avoid false-positive lockdep splat on rule deletion")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-12-09 10:32:07 +01:00
Pablo Neira Ayuso
bfd05c68e4 netfilter: nf_tables: wait for rcu grace period on net_device removal
[ Upstream commit c03d278fdf35e73dd0ec543b9b556876b9d9a8dc ]

8c873e2199 ("netfilter: core: free hooks with call_rcu") removed
synchronize_net() call when unregistering basechain hook, however,
net_device removal event handler for the NFPROTO_NETDEV was not updated
to wait for RCU grace period.

Note that 835b803377 ("netfilter: nf_tables_netdev: unregister hooks
on net_device removal") does not remove basechain rules on device
removal, I was hinted to remove rules on net_device removal later, see
5ebe0b0eec ("netfilter: nf_tables: destroy basechain and rules on
netdevice removal").

Although NETDEV_UNREGISTER event is guaranteed to be handled after
synchronize_net() call, this path needs to wait for rcu grace period via
rcu callback to release basechain hooks if netns is alive because an
ongoing netlink dump could be in progress (sockets hold a reference on
the netns).

Note that nf_tables_pre_exit_net() unregisters and releases basechain
hooks but it is possible to see NETDEV_UNREGISTER at a later stage in
the netns exit path, eg. veth peer device in another netns:

 cleanup_net()
  default_device_exit_batch()
   unregister_netdevice_many_notify()
    notifier_call_chain()
     nf_tables_netdev_event()
      __nft_release_basechain()

In this particular case, same rule of thumb applies: if netns is alive,
then wait for rcu grace period because netlink dump in the other netns
could be in progress. Otherwise, if the other netns is going away then
no netlink dump can be in progress and basechain hooks can be released
inmediately.

While at it, turn WARN_ON() into WARN_ON_ONCE() for the basechain
validation, which should not ever happen.

Fixes: 835b803377 ("netfilter: nf_tables_netdev: unregister hooks on net_device removal")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-14 13:19:32 +01:00
Florian Westphal
825a80817c netfilter: nf_tables: pass nft_chain to destroy function, not nft_ctx
[ Upstream commit 8965d42bcf54d42cbc72fe34a9d0ec3f8527debd ]

It would be better to not store nft_ctx inside nft_trans object,
the netlink ctx strucutre is huge and most of its information is
never needed in places that use trans->ctx.

Avoid/reduce its usage if possible, no runtime behaviour change
intended.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: c03d278fdf35 ("netfilter: nf_tables: wait for rcu grace period on net_device removal")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-14 13:19:32 +01:00
Pablo Neira Ayuso
0ab3be58b4 netfilter: nft_payload: sanitize offset and length before calling skb_checksum()
[ Upstream commit d5953d680f7e96208c29ce4139a0e38de87a57fe ]

If access to offset + length is larger than the skbuff length, then
skb_checksum() triggers BUG_ON().

skb_checksum() internally subtracts the length parameter while iterating
over skbuff, BUG_ON(len) at the end of it checks that the expected
length to be included in the checksum calculation is fully consumed.

Fixes: 7ec3f7b47b ("netfilter: nft_payload: add packet mangling support")
Reported-by: Slavin Liu <slavin-ayu@qq.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08 16:28:19 +01:00
Dong Chenchen
6a1f088f98 netfilter: Fix use-after-free in get_info()
[ Upstream commit f48d258f0ac540f00fa617dac496c4c18b5dc2fa ]

ip6table_nat module unload has refcnt warning for UAF. call trace is:

WARNING: CPU: 1 PID: 379 at kernel/module/main.c:853 module_put+0x6f/0x80
Modules linked in: ip6table_nat(-)
CPU: 1 UID: 0 PID: 379 Comm: ip6tables Not tainted 6.12.0-rc4-00047-gc2ee9f594da8-dirty #205
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),
BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:module_put+0x6f/0x80
Call Trace:
 <TASK>
 get_info+0x128/0x180
 do_ip6t_get_ctl+0x6a/0x430
 nf_getsockopt+0x46/0x80
 ipv6_getsockopt+0xb9/0x100
 rawv6_getsockopt+0x42/0x190
 do_sock_getsockopt+0xaa/0x180
 __sys_getsockopt+0x70/0xc0
 __x64_sys_getsockopt+0x20/0x30
 do_syscall_64+0xa2/0x1a0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Concurrent execution of module unload and get_info() trigered the warning.
The root cause is as follows:

cpu0				      cpu1
module_exit
//mod->state = MODULE_STATE_GOING
  ip6table_nat_exit
    xt_unregister_template
	kfree(t)
	//removed from templ_list
				      getinfo()
					  t = xt_find_table_lock
						list_for_each_entry(tmpl, &xt_templates[af]...)
							if (strcmp(tmpl->name, name))
								continue;  //table not found
							try_module_get
						list_for_each_entry(t, &xt_net->tables[af]...)
							return t;  //not get refcnt
					  module_put(t->me) //uaf
    unregister_pernet_subsys
    //remove table from xt_net list

While xt_table module was going away and has been removed from
xt_templates list, we couldnt get refcnt of xt_table->me. Check
module in xt_net->tables list re-traversal to fix it.

Fixes: fdacd57c79 ("netfilter: x_tables: never register tables by default")
Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-08 16:28:19 +01:00
Pablo Neira Ayuso
433742ba96 netfilter: xtables: fix typo causing some targets not to load on IPv6
[ Upstream commit 306ed1728e8438caed30332e1ab46b28c25fe3d8 ]

- There is no NFPROTO_IPV6 family for mark and NFLOG.
- TRACE is also missing module autoload with NFPROTO_IPV6.

This results in ip6tables failing to restore a ruleset. This issue has been
reported by several users providing incomplete patches.

Very similar to Ilya Katsnelson's patch including a missing chunk in the
TRACE extension.

Fixes: 0bfcb7b71e73 ("netfilter: xtables: avoid NFPROTO_UNSPEC where needed")
Reported-by: Ignat Korchagin <ignat@cloudflare.com>
Reported-by: Ilya Katsnelson <me@0upti.me>
Reported-by: Krzysztof Olędzki <ole@ans.pl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-01 01:58:29 +01:00
Florian Westphal
f41bd93b3e netfilter: bpf: must hold reference on net namespace
[ Upstream commit 1230fe7ad3974f7bf6c78901473e039b34d4fb1f ]

BUG: KASAN: slab-use-after-free in __nf_unregister_net_hook+0x640/0x6b0
Read of size 8 at addr ffff8880106fe400 by task repro/72=
bpf_nf_link_release+0xda/0x1e0
bpf_link_free+0x139/0x2d0
bpf_link_release+0x68/0x80
__fput+0x414/0xb60

Eric says:
 It seems that bpf was able to defer the __nf_unregister_net_hook()
 after exit()/close() time.
 Perhaps a netns reference is missing, because the netns has been
 dismantled/freed already.
 bpf_nf_link_attach() does :
 link->net = net;
 But I do not see a reference being taken on net.

Add such a reference and release it after hook unreg.
Note that I was unable to get syzbot reproducer to work, so I
do not know if this resolves this splat.

Fixes: 84601d6ee6 ("bpf: add bpf_link support for BPF_NETFILTER programs")
Diagnosed-by: Eric Dumazet <edumazet@google.com>
Reported-by: Lai, Yi <yi1.lai@linux.intel.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-01 01:58:28 +01:00
Tyrone Wu
97bbdc5001 bpf: Fix link info netfilter flags to populate defrag flag
[ Upstream commit 92f3715e1eba1d41e55be06159dc3d856b18326d ]

This fix correctly populates the `bpf_link_info.netfilter.flags` field
when user passes the `BPF_F_NETFILTER_IP_DEFRAG` flag.

Fixes: 91721c2d02 ("netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link")
Signed-off-by: Tyrone Wu <wudevelops@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Florian Westphal <fw@strlen.de>
Cc: Daniel Xu <dxu@dxuuu.xyz>
Link: https://lore.kernel.org/bpf/20241011193252.178997-1-wudevelops@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-11-01 01:58:24 +01:00
Florian Westphal
997f67d813 netfilter: xtables: avoid NFPROTO_UNSPEC where needed
[ Upstream commit 0bfcb7b71e735560077a42847f69597ec7dcc326 ]

syzbot managed to call xt_cluster match via ebtables:

 WARNING: CPU: 0 PID: 11 at net/netfilter/xt_cluster.c:72 xt_cluster_mt+0x196/0x780
 [..]
 ebt_do_table+0x174b/0x2a40

Module registers to NFPROTO_UNSPEC, but it assumes ipv4/ipv6 packet
processing.  As this is only useful to restrict locally terminating
TCP/UDP traffic, register this for ipv4 and ipv6 family only.

Pablo points out that this is a general issue, direct users of the
set/getsockopt interface can call into targets/matches that were only
intended for use with ip(6)tables.

Check all UNSPEC matches and targets for similar issues:

- matches and targets are fine except if they assume skb_network_header()
  is valid -- this is only true when called from inet layer: ip(6) stack
  pulls the ip/ipv6 header into linear data area.
- targets that return XT_CONTINUE or other xtables verdicts must be
  restricted too, they are incompatbile with the ebtables traverser, e.g.
  EBT_CONTINUE is a completely different value than XT_CONTINUE.

Most matches/targets are changed to register for NFPROTO_IPV4/IPV6, as
they are provided for use by ip(6)tables.

The MARK target is also used by arptables, so register for NFPROTO_ARP too.

While at it, bail out if connbytes fails to enable the corresponding
conntrack family.

This change passes the selftests in iptables.git.

Reported-by: syzbot+256c348558aa5cf611a9@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netfilter-devel/66fec2e2.050a0220.9ec68.0047.GAE@google.com/
Fixes: 0269ea4937 ("netfilter: xtables: add cluster match")
Signed-off-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-17 15:24:28 +02:00
Florian Westphal
5b04f41aba netfilter: nf_nat: don't try nat source port reallocation for reverse dir clash
[ Upstream commit d8f84a9bc7c4e07fdc4edc00f9e868b8db974ccb ]

A conntrack entry can be inserted to the connection tracking table if there
is no existing entry with an identical tuple in either direction.

Example:
INITIATOR -> NAT/PAT -> RESPONDER

Initiator passes through NAT/PAT ("us") and SNAT is done (saddr rewrite).
Then, later, NAT/PAT machine itself also wants to connect to RESPONDER.

This will not work if the SNAT done earlier has same IP:PORT source pair.

Conntrack table has:
ORIGINAL: $IP_INITATOR:$SPORT -> $IP_RESPONDER:$DPORT
REPLY:    $IP_RESPONDER:$DPORT -> $IP_NAT:$SPORT

and new locally originating connection wants:
ORIGINAL: $IP_NAT:$SPORT -> $IP_RESPONDER:$DPORT
REPLY:    $IP_RESPONDER:$DPORT -> $IP_NAT:$SPORT

This is handled by the NAT engine which will do a source port reallocation
for the locally originating connection that is colliding with an existing
tuple by attempting a source port rewrite.

This is done even if this new connection attempt did not go through a
masquerade/snat rule.

There is a rare race condition with connection-less protocols like UDP,
where we do the port reallocation even though its not needed.

This happens when new packets from the same, pre-existing flow are received
in both directions at the exact same time on different CPUs after the
conntrack table was flushed (or conntrack becomes active for first time).

With strict ordering/single cpu, the first packet creates new ct entry and
second packet is resolved as established reply packet.

With parallel processing, both packets are picked up as new and both get
their own ct entry.

In this case, the 'reply' packet (picked up as ORIGINAL) can be mangled by
NAT engine because a port collision is detected.

This change isn't enough to prevent a packet drop later during
nf_conntrack_confirm(), the existing clash resolution strategy will not
detect such reverse clash case.  This is resolved by a followup patch.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-10-17 15:24:20 +02:00
Pablo Neira Ayuso
164936b2fc netfilter: nf_tables: restore set elements when delete set fails
>From abort path, nft_mapelem_activate() needs to restore refcounters to
the original state. Currently, it uses the set->ops->walk() to iterate
over these set elements. The existing set iterator skips inactive
elements in the next generation, this does not work from the abort path
to restore the original state since it has to skip active elements
instead (not inactive ones).

This patch moves the check for inactive elements to the set iterator
callback, then it reverses the logic for the .activate case which
needs to skip active elements.

Toggle next generation bit for elements when delete set command is
invoked and call nft_clear() from .activate (abort) path to restore the
next generation bit.

The splat below shows an object in mappings memleak:

[43929.457523] ------------[ cut here ]------------
[43929.457532] WARNING: CPU: 0 PID: 1139 at include/net/netfilter/nf_tables.h:1237 nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[...]
[43929.458014] RIP: 0010:nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[43929.458076] Code: 83 f8 01 77 ab 49 8d 7c 24 08 e8 37 5e d0 de 49 8b 6c 24 08 48 8d 7d 50 e8 e9 5c d0 de 8b 45 50 8d 50 ff 89 55 50 85 c0 75 86 <0f> 0b eb 82 0f 0b eb b3 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90
[43929.458081] RSP: 0018:ffff888140f9f4b0 EFLAGS: 00010246
[43929.458086] RAX: 0000000000000000 RBX: ffff8881434f5288 RCX: dffffc0000000000
[43929.458090] RDX: 00000000ffffffff RSI: ffffffffa26d28a7 RDI: ffff88810ecc9550
[43929.458093] RBP: ffff88810ecc9500 R08: 0000000000000001 R09: ffffed10281f3e8f
[43929.458096] R10: 0000000000000003 R11: ffff0000ffff0000 R12: ffff8881434f52a0
[43929.458100] R13: ffff888140f9f5f4 R14: ffff888151c7a800 R15: 0000000000000002
[43929.458103] FS:  00007f0c687c4740(0000) GS:ffff888390800000(0000) knlGS:0000000000000000
[43929.458107] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[43929.458111] CR2: 00007f58dbe5b008 CR3: 0000000123602005 CR4: 00000000001706f0
[43929.458114] Call Trace:
[43929.458118]  <TASK>
[43929.458121]  ? __warn+0x9f/0x1a0
[43929.458127]  ? nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[43929.458188]  ? report_bug+0x1b1/0x1e0
[43929.458196]  ? handle_bug+0x3c/0x70
[43929.458200]  ? exc_invalid_op+0x17/0x40
[43929.458211]  ? nft_setelem_data_deactivate+0xd7/0xf0 [nf_tables]
[43929.458271]  ? nft_setelem_data_deactivate+0xe4/0xf0 [nf_tables]
[43929.458332]  nft_mapelem_deactivate+0x24/0x30 [nf_tables]
[43929.458392]  nft_rhash_walk+0xdd/0x180 [nf_tables]
[43929.458453]  ? __pfx_nft_rhash_walk+0x10/0x10 [nf_tables]
[43929.458512]  ? rb_insert_color+0x2e/0x280
[43929.458520]  nft_map_deactivate+0xdc/0x1e0 [nf_tables]
[43929.458582]  ? __pfx_nft_map_deactivate+0x10/0x10 [nf_tables]
[43929.458642]  ? __pfx_nft_mapelem_deactivate+0x10/0x10 [nf_tables]
[43929.458701]  ? __rcu_read_unlock+0x46/0x70
[43929.458709]  nft_delset+0xff/0x110 [nf_tables]
[43929.458769]  nft_flush_table+0x16f/0x460 [nf_tables]
[43929.458830]  nf_tables_deltable+0x501/0x580 [nf_tables]

Fixes: 628bd3e49c ("netfilter: nf_tables: drop map element references from preparation phase")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(cherry picked from commit e79b47a8615d42c68aaeb68971593333667382ed)
[Vegard: CVE-2024-27012; fixed conflicts due to missing commits
 0e1ea651c9717ddcd8e0648d8468477a31867b0a ("netfilter: nf_tables: shrink
 memory consumption of set elements") and
 9dad402b89e81a0516bad5e0ac009b7a0a80898f ("netfilter: nf_tables: expose
 opaque set element as struct nft_elem_priv") so we pass the correct types
 and values to nft_setelem_data_deactivate(), nft_setelem_validate(),
 nft_set_elem_ext(), etc.]
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-10 11:58:07 +02:00