linux.git/net/netfilter, branch v6.11

net: netfilter: move nf flowtable bpf initialization in nf_flow_table_module_init()

2024-09-12T13:41:03+00:00

Move nf flowtable bpf initialization in nf_flow_table module load
routine since nf_flow_table_bpf is part of nf_flow_table module and not
nf_flow_table_inet one. This patch allows to avoid the following kernel
warning running the reproducer below:

$modprobe nf_flow_table_inet
$rmmod nf_flow_table_inet
$modprobe nf_flow_table_inet
modprobe: ERROR: could not insert 'nf_flow_table_inet': Invalid argument

[  184.081501] ------------[ cut here ]------------
[  184.081527] WARNING: CPU: 0 PID: 1362 at kernel/bpf/btf.c:8206 btf_populate_kfunc_set+0x23c/0x330
[  184.081550] CPU: 0 UID: 0 PID: 1362 Comm: modprobe Kdump: loaded Not tainted 6.11.0-0.rc5.22.el10.x86_64 #1
[  184.081553] Hardware name: Red Hat OpenStack Compute, BIOS 1.14.0-1.module+el8.4.0+8855+a9e237a9 04/01/2014
[  184.081554] RIP: 0010:btf_populate_kfunc_set+0x23c/0x330
[  184.081558] RSP: 0018:ff22cfb38071fc90 EFLAGS: 00010202
[  184.081559] RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000
[  184.081560] RDX: 000000000000006e RSI: ffffffff95c00000 RDI: ff13805543436350
[  184.081561] RBP: ffffffffc0e22180 R08: ff13805543410808 R09: 000000000001ec00
[  184.081562] R10: ff13805541c8113c R11: 0000000000000010 R12: ff13805541b83c00
[  184.081563] R13: ff13805543410800 R14: 0000000000000001 R15: ffffffffc0e2259a
[  184.081564] FS:  00007fa436c46740(0000) GS:ff1380557ba00000(0000) knlGS:0000000000000000
[  184.081569] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  184.081570] CR2: 000055e7b3187000 CR3: 0000000100c48003 CR4: 0000000000771ef0
[  184.081571] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  184.081572] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  184.081572] PKRU: 55555554
[  184.081574] Call Trace:
[  184.081575]  
[  184.081578]  ? show_trace_log_lvl+0x1b0/0x2f0
[  184.081580]  ? show_trace_log_lvl+0x1b0/0x2f0
[  184.081582]  ? __register_btf_kfunc_id_set+0x199/0x200
[  184.081585]  ? btf_populate_kfunc_set+0x23c/0x330
[  184.081586]  ? __warn.cold+0x93/0xed
[  184.081590]  ? btf_populate_kfunc_set+0x23c/0x330
[  184.081592]  ? report_bug+0xff/0x140
[  184.081594]  ? handle_bug+0x3a/0x70
[  184.081596]  ? exc_invalid_op+0x17/0x70
[  184.081597]  ? asm_exc_invalid_op+0x1a/0x20
[  184.081601]  ? btf_populate_kfunc_set+0x23c/0x330
[  184.081602]  __register_btf_kfunc_id_set+0x199/0x200
[  184.081605]  ? __pfx_nf_flow_inet_module_init+0x10/0x10 [nf_flow_table_inet]
[  184.081607]  do_one_initcall+0x58/0x300
[  184.081611]  do_init_module+0x60/0x230
[  184.081614]  __do_sys_init_module+0x17a/0x1b0
[  184.081617]  do_syscall_64+0x7d/0x160
[  184.081620]  ? __count_memcg_events+0x58/0xf0
[  184.081623]  ? handle_mm_fault+0x234/0x350
[  184.081626]  ? do_user_addr_fault+0x347/0x640
[  184.081630]  ? clear_bhb_loop+0x25/0x80
[  184.081633]  ? clear_bhb_loop+0x25/0x80
[  184.081634]  ? clear_bhb_loop+0x25/0x80
[  184.081637]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  184.081639] RIP: 0033:0x7fa43652e4ce
[  184.081647] RSP: 002b:00007ffe8213be18 EFLAGS: 00000246 ORIG_RAX: 00000000000000af
[  184.081649] RAX: ffffffffffffffda RBX: 000055e7b3176c20 RCX: 00007fa43652e4ce
[  184.081650] RDX: 000055e7737fde79 RSI: 0000000000003990 RDI: 000055e7b3185380
[  184.081651] RBP: 000055e7737fde79 R08: 0000000000000007 R09: 000055e7b3179bd0
[  184.081651] R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000040000
[  184.081652] R13: 000055e7b3176fa0 R14: 0000000000000000 R15: 000055e7b3179b80

Fixes: 391bb6594fd3 ("netfilter: Add bpf_xdp_flow_lookup kfunc")
Signed-off-by: Lorenzo Bianconi 
Acked-by: Florian Westphal 
Acked-by: Pablo Neira Ayuso 
Link: https://patch.msgid.link/20240911-nf-flowtable-bpf-modprob-fix-v1-1-f9fc075aafc3@kernel.org
Signed-off-by: Paolo Abeni

netfilter: nft_socket: make cgroupsv2 matching work with namespaces

2024-09-11T22:16:58+00:00

When running in container environmment, /sys/fs/cgroup/ might not be
the real root node of the sk-attached cgroup.

Example:

In container:
% stat /sys//fs/cgroup/
Device: 0,21    Inode: 2214  ..
% stat /sys/fs/cgroup/foo
Device: 0,21    Inode: 2264  ..

The expectation would be for:

  nft add rule .. socket cgroupv2 level 1 "foo" counter

to match traffic from a process that got added to "foo" via
"echo $pid > /sys/fs/cgroup/foo/cgroup.procs".

However, 'level 3' is needed to make this work.

Seen from initial namespace, the complete hierarchy is:

% stat /sys/fs/cgroup/system.slice/docker-.../foo
  Device: 0,21    Inode: 2264 ..

i.e. hierarchy is
0    1               2              3
/ -> system.slice -> docker-1... -> foo

... but the container doesn't know that its "/" is the "docker-1.."
cgroup.  Current code will retrieve the 'system.slice' cgroup node
and store its kn->id in the destination register, so compare with
2264 ("foo" cgroup id) will not match.

Fetch "/" cgroup from ->init() and add its level to the level we try to
extract.  cgroup root-level is 0 for the init-namespace or the level
of the ancestor that is exposed as the cgroup root inside the container.

In the above case, cgrp->level of "/" resolved in the container is 2
(docker-1...scope/) and request for 'level 1' will get adjusted
to fetch the actual level (3).

v2: use CONFIG_SOCK_CGROUP_DATA, eval function depends on it.
    (kernel test robot)

Cc: cgroups@vger.kernel.org
Fixes: e0bb96db96f8 ("netfilter: nft_socket: add support for cgroupsv2")
Reported-by: Nadia Pinaeva 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_socket: fix sk refcount leaks

2024-09-11T22:16:54+00:00

We must put 'sk' reference before returning.

Fixes: 039b1f4f24ec ("netfilter: nft_socket: fix erroneous socket assignment")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: flowtable: validate vlan header

2024-08-22T10:14:18+00:00

Ensure there is sufficient room to access the protocol field of the
VLAN header, validate it once before the flowtable lookup.

=====================================================
BUG: KMSAN: uninit-value in nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32
 nf_flow_offload_inet_hook+0x45a/0x5f0 net/netfilter/nf_flow_table_inet.c:32
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626
 nf_hook_ingress include/linux/netfilter_netdev.h:34 [inline]
 nf_ingress net/core/dev.c:5440 [inline]

Fixes: 4cd91f7c290f ("netfilter: flowtable: add vlan support")
Reported-by: syzbot+8407d9bb88cd4c6bf61a@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_counter: Synchronize nft_counter_reset() against reader.

2024-08-20T10:26:36+00:00

nft_counter_reset() resets the counter by subtracting the previously
retrieved value from the counter. This is a write operation on the
counter and as such it requires to be performed with a write sequence of
nft_counter_seq to serialize against its possible reader.

Update the packets/ bytes within write-sequence of nft_counter_seq.

Fixes: d84701ecbcd6a ("netfilter: nft_counter: rework atomic dump and reset")
Signed-off-by: Sebastian Andrzej Siewior 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_counter: Disable BH in nft_counter_offload_stats().

2024-08-20T10:26:22+00:00

The sequence counter nft_counter_seq is a per-CPU counter. There is no
lock associated with it. nft_counter_do_eval() is using the same counter
and disables BH which suggest that it can be invoked from a softirq.
This in turn means that nft_counter_offload_stats(), which disables only
preemption, can be interrupted by nft_counter_do_eval() leading to two
writer for one seqcount_t.
This can lead to loosing stats or reading statistics while they are
updated.

Disable BH during stats update in nft_counter_offload_stats() to ensure
one writer at a time.

Fixes: b72920f6e4a9d ("netfilter: nftables: counter hardware offload support")
Signed-off-by: Sebastian Andrzej Siewior 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: Add locking for NFT_MSG_GETOBJ_RESET requests

2024-08-14T21:44:55+00:00

Objects' dump callbacks are not concurrency-safe per-se with reset bit
set. If two CPUs perform a reset at the same time, at least counter and
quota objects suffer from value underrun.

Prevent this by introducing dedicated locking callbacks for nfnetlink
and the asynchronous dump handling to serialize access.

Fixes: 43da04a593d8 ("netfilter: nf_tables: atomic dump and reset for stateful objects")
Signed-off-by: Phil Sutter 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: Introduce nf_tables_getobj_single

2024-08-14T21:37:44+00:00

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

Signed-off-by: Phil Sutter 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: Audit log dump reset after the fact

2024-08-14T21:37:35+00:00

In theory, dumpreset may fail and invalidate the preceeding log message.
Fix this and use the occasion to prepare for object reset locking, which
benefits from a few unrelated changes:

* Add an early call to nfnetlink_unicast if not resetting which
  effectively skips the audit logging but also unindents it.
* Extract the table's name from the netlink attribute (which is verified
  via earlier table lookup) to not rely upon validity of the looked up
  table pointer.
* Do not use local variable family, it will vanish.

Fixes: 8e6cf365e1d5 ("audit: log nftables configuration change events")
Signed-off-by: Phil Sutter 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_queue: drop packets with cloned unconfirmed conntracks

2024-08-14T21:37:23+00:00

Conntrack assumes an unconfirmed entry (not yet committed to global hash
table) has a refcount of 1 and is not visible to other cores.

With multicast forwarding this assumption breaks down because such
skbs get cloned after being picked up, i.e.  ct->use refcount is > 1.

Likewise, bridge netfilter will clone broad/mutlicast frames and
all frames in case they need to be flood-forwarded during learning
phase.

For ip multicast forwarding or plain bridge flood-forward this will
"work" because packets don't leave softirq and are implicitly
serialized.

With nfqueue this no longer holds true, the packets get queued
and can be reinjected in arbitrary ways.

Disable this feature, I see no other solution.

After this patch, nfqueue cannot queue packets except the last
multicast/broadcast packet.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso