linux.git/net/netfilter, branch v6.8-rc2

netfilter: nf_tables: validate NFPROTO_* family

2024-01-24T19:02:40+00:00

Several expressions explicitly refer to NF_INET_* hook definitions
from expr->ops->validate, however, family is not validated.

Bail out with EOPNOTSUPP in case they are used from unsupported
families.

Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables")
Fixes: a3c90f7a2323 ("netfilter: nf_tables: flow offload expression")
Fixes: 2fa841938c64 ("netfilter: nf_tables: introduce routing expression")
Fixes: 554ced0a6e29 ("netfilter: nf_tables: add support for native socket matching")
Fixes: ad49d86e07a4 ("netfilter: nf_tables: Add synproxy support")
Fixes: 4ed8eb6570a4 ("netfilter: nf_tables: Add native tproxy support")
Fixes: 6c47260250fc ("netfilter: nf_tables: add xfrm expression")
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: reject QUEUE/DROP verdict parameters

2024-01-24T19:02:39+00:00

This reverts commit e0abdadcc6e1.

core.c:nf_hook_slow assumes that the upper 16 bits of NF_DROP
verdicts contain a valid errno, i.e. -EPERM, -EHOSTUNREACH or similar,
or 0.

Due to the reverted commit, its possible to provide a positive
value, e.g. NF_ACCEPT (1), which results in use-after-free.

Its not clear to me why this commit was made.

NF_QUEUE is not used by nftables; "queue" rules in nftables
will result in use of "nft_queue" expression.

If we later need to allow specifiying errno values from userspace
(do not know why), this has to call NF_DROP_GETERR and check that
"err <= 0" holds true.

Fixes: e0abdadcc6e1 ("netfilter: nf_tables: accept QUEUE/DROP verdict parameters")
Cc: stable@vger.kernel.org
Reported-by: Notselwyn 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: restrict anonymous set and map names to 16 bytes

2024-01-24T19:02:30+00:00

nftables has two types of sets/maps, one where userspace defines the
name, and anonymous sets/maps, where userspace defines a template name.

For the latter, kernel requires presence of exactly one "%d".
nftables uses "__set%d" and "__map%d" for this.  The kernel will
expand the format specifier and replaces it with the smallest unused
number.

As-is, userspace could define a template name that allows to move
the set name past the 256 bytes upperlimit (post-expansion).

I don't see how this could be a problem, but I would prefer if userspace
cannot do this, so add a limit of 16 bytes for the '%d' template name.

16 bytes is the old total upper limit for set names that existed when
nf_tables was merged initially.

Fixes: 387454901bd6 ("netfilter: nf_tables: Allow set names of up to 255 chars")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_limit: reject configurations that cause integer overflow

2024-01-24T19:01:16+00:00

Reject bogus configs where internal token counter wraps around.
This only occurs with very very large requests, such as 17gbyte/s.

Its better to reject this rather than having incorrect ratelimit.

Fixes: d2168e849ebf ("netfilter: nft_limit: add per-byte limiting")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_chain_filter: handle NETDEV_UNREGISTER for inet/ingress basechain

2024-01-24T18:50:21+00:00

Remove netdevice from inet/ingress basechain in case NETDEV_UNREGISTER
event is reported, otherwise a stale reference to netdevice remains in
the hook list.

Fixes: 60a3815da702 ("netfilter: add inet ingress support")
Cc: stable@vger.kernel.org
Signed-off-by: Pablo Neira Ayuso

ipvs: avoid stat macros calls from preemptible context

2024-01-17T11:02:51+00:00

Inside decrement_ttl() upon discovering that the packet ttl has exceeded,
__IP_INC_STATS and __IP6_INC_STATS macros can be called from preemptible
context having the following backtrace:

check_preemption_disabled: 48 callbacks suppressed
BUG: using __this_cpu_add() in preemptible [00000000] code: curl/1177
caller is decrement_ttl+0x217/0x830
CPU: 5 PID: 1177 Comm: curl Not tainted 6.7.0+ #34
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 04/01/2014
Call Trace:
 
 dump_stack_lvl+0xbd/0xe0
 check_preemption_disabled+0xd1/0xe0
 decrement_ttl+0x217/0x830
 __ip_vs_get_out_rt+0x4e0/0x1ef0
 ip_vs_nat_xmit+0x205/0xcd0
 ip_vs_in_hook+0x9b1/0x26a0
 nf_hook_slow+0xc2/0x210
 nf_hook+0x1fb/0x770
 __ip_local_out+0x33b/0x640
 ip_local_out+0x2a/0x490
 __ip_queue_xmit+0x990/0x1d10
 __tcp_transmit_skb+0x288b/0x3d10
 tcp_connect+0x3466/0x5180
 tcp_v4_connect+0x1535/0x1bb0
 __inet_stream_connect+0x40d/0x1040
 inet_stream_connect+0x57/0xa0
 __sys_connect_file+0x162/0x1a0
 __sys_connect+0x137/0x160
 __x64_sys_connect+0x72/0xb0
 do_syscall_64+0x6f/0x140
 entry_SYSCALL_64_after_hwframe+0x6e/0x76
RIP: 0033:0x7fe6dbbc34e0

Use the corresponding preemption-aware variants: IP_INC_STATS and
IP6_INC_STATS.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 8d8e20e2d7bb ("ipvs: Decrement ttl")
Signed-off-by: Fedor Pchelkin 
Acked-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: reject NFT_SET_CONCAT with not field length description

2024-01-17T11:02:51+00:00

It is still possible to set on the NFT_SET_CONCAT flag by specifying a
set size and no field description, report EINVAL in such case.

Fixes: 1b6345d4160e ("netfilter: nf_tables: check NFT_SET_CONCAT flag if field_count is specified")
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: skip dead set elements in netlink dump

2024-01-17T11:02:50+00:00

Delete from packet path relies on the garbage collector to purge
elements with NFT_SET_ELEM_DEAD_BIT on.

Skip these dead elements from nf_tables_dump_setelem() path, I very
rarely see tests/shell/testcases/maps/typeof_maps_add_delete reports
[DUMP FAILED] showing a mismatch in the expected output with an element
that should not be there.

If the netlink dump happens before GC worker run, it might show dead
elements in the ruleset listing.

nft_rhash_get() already skips dead elements in nft_rhash_cmp(),
therefore, it already does not show the element when getting a single
element via netlink control plane.

Fixes: 5f68718b34a5 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: do not allow mismatch field size and set key length

2024-01-17T11:02:50+00:00

The set description provides the size of each field in the set whose sum
should not mismatch the set key length, bail out otherwise.

I did not manage to crash nft_set_pipapo with mismatch fields and set key
length so far, but this is UB which must be disallowed.

Fixes: f3a2181e16f1 ("netfilter: nf_tables: Support for sets with multiple ranged fields")
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: check if catch-all set element is active in next generation

2024-01-17T11:02:49+00:00

When deactivating the catch-all set element, check the state in the next
generation that represents this transaction.

This bug uncovered after the recent removal of the element busy mark
a2dd0233cbc4 ("netfilter: nf_tables: remove busy mark and gc batch API").

Fixes: aaa31047a6d2 ("netfilter: nftables: add catch-all set element support")
Cc: stable@vger.kernel.org
Reported-by: lonial con 
Signed-off-by: Pablo Neira Ayuso