nf_log_unregister() runs after the per-net teardown so its final RCU
grace period also drains readers that obtained the logger from a per-net
binding. However, ebt_nflog passes an explicit ULOG log type to
nf_log_packet() without holding a reference on the selected logger module,
unlike the xt_NFLOG and nft_log frontends.
An ebtables nflog rule can therefore remain callable while nfnetlink_log
is unloaded. The resulting interleaving is:
CPU 0 CPU 1
nfnetlink_log_fini()
unregister_pernet_subsys()
kfree(nfnl_log_pernet(net))
ebt_nflog_tg()
nf_log_packet()
nfulnl_log_packet()
instance_lookup_get_rcu()
The global ULOG logger is still registered at this point, so CPU 1
dereferences the per-net state after CPU 0 has freed it. KASAN reported:
BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu
Read of size 8 at addr ff110001052e6210 by task poc/92
Call Trace:
instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log]
nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log]
nf_log_packet+0x204/0x300
ebt_nflog_tg+0x351/0x550
ebt_do_table+0xedf/0x22b0
Allocated by task 90:
__kmalloc_noprof+0x186/0x470
ops_init+0x6d/0x420
register_pernet_operations+0x2f6/0x670
register_pernet_subsys+0x23/0x40
Freed by task 93:
kfree+0x131/0x3c0
ops_undo_list+0x3e3/0x700
unregister_pernet_operations+0x232/0x490
unregister_pernet_subsys+0x1c/0x30
nfnetlink_log_fini+0x34/0x450 [nfnetlink_log]
Acquire the ULOG logger module reference when an ebt_nflog rule is
validated and release it when the rule is destroyed. Request the NFLOG
backend for legacy callers when needed, matching xt_NFLOG. This prevents
module teardown until all ebt_nflog rules have stopped using the logger.
Fixes: c83fa19603 ("netfilter: nf_log: don't call synchronize_rcu in nf_log_unset")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
We need to explicitly check the length, else we may pass non-null
terminated string to request_module().
Cc: [email protected]
Fixes: bcf4934288 ("netfilter: ebtables: Fix extension lookup with identical name")
Signed-off-by: Florian Westphal <[email protected]>
sashiko reports:
looking at ebtables table
translation, could a sparse cpu_possible_mask lead to an uninitialized pointer
free?
If cpu_possible_mask is sparse (for example, CPU 0 and CPU 2 are possible,
but CPU 1 is not), the allocation loop skips CPU 1. If vmalloc_node() fails at
CPU 2, the cleanup loop will blindly decrement and call vfree() on
newinfo->chainstack[1].
Not a real-world bug, such allocation isn't expected to fail
in the first place.
Cc: [email protected]
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Florian Westphal <[email protected]>
update_counters() and compat_update_counters() forward a user-supplied
32-byte table name to find_table_lock() without NUL-terminating it. On a
lookup miss, find_inlist_lock() calls try_then_request_module(..., "%s%s",
"ebtable_", name), and vsnprintf() reads past the name field and the
stack object until it hits a zero byte.
BUG: KASAN: stack-out-of-bounds in string (lib/vsprintf.c:648 lib/vsprintf.c:730)
Read of size 1 at addr ffff8880119dfb20 by task exploit/147
Call Trace:
...
string (lib/vsprintf.c:648 lib/vsprintf.c:730)
vsnprintf (lib/vsprintf.c:2945)
__request_module (kernel/module/kmod.c:150)
do_update_counters.isra.0 (net/bridge/netfilter/ebtables.c:371 net/bridge/netfilter/ebtables.c:380)
update_counters (net/bridge/netfilter/ebtables.c:1440)
do_ebt_set_ctl (net/bridge/netfilter/ebtables.c:2573)
nf_setsockopt (net/netfilter/nf_sockopt.c:101)
ip_setsockopt (net/ipv4/ip_sockglue.c:1424)
raw_setsockopt (net/ipv4/raw.c:847)
__sys_setsockopt (net/socket.c:2393)
...
compat_do_replace() shares the same unterminated name via
compat_copy_ebt_replace_from_user(); terminate it there too so all
find_table_lock() callers behave alike. The other callers already
terminate the name after the copy.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Fixes: 81e675c227 ("netfilter: ebtables: add CONFIG_COMPAT support")
Cc: [email protected]
Reported-by: Weiming Shi <[email protected]>
Assisted-by: Claude:claude-opus-4-8
Signed-off-by: Xiang Mei <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Blamed commit added NFT_META_BRI_IIFHWADDR to the set validate callback,
yet this is a get operation.
Add a get validate callback and move the NFT_META_BRI_IIFHWADDR key
there.
AFAICS this is harmless, NFT_META_BRI_IIFHWADDR can deal with a NULL
input device and the set handler ignores a NFT_META_BRI_IIFHWADDR
operation, but it allows to read 4 bytes off bridge skb->cb[].
Fixes: cbd2257dc9 ("netfilter: nft_meta_bridge: introduce NFT_META_BRI_IIFHWADDR support")
Signed-off-by: Florian Westphal <[email protected]>
Reviewed-by: Fernando Fernandez Mancera <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Cross-merge networking fixes after downstream PR (net-7.1-rc8).
Conflicts:
drivers/net/ethernet/wangxun/txgbe/txgbe_aml.c
f67aead16e ("net: txgbe: rework service event handling")
57d39faed4 ("net: txgbe: improve functions of AML 40G devices")
net/rds/info.c
512db8267b ("rds: mark snapshot pages dirty in rds_info_getsockopt()")
6e94eeb2a2 ("rds: convert to getsockopt_iter")
Adjacent changes:
include/net/sock.h
1ee90b77b7 ("net: guard timestamp cmsgs to real error queue skbs")
f0de88303d ("net: make is_skb_wmem() available to modules")
Signed-off-by: Jakub Kicinski <[email protected]>
NFT_META_BRI_IIFHWADDR declares its destination register with
len = ETH_ALEN (6 bytes), which the register-init tracking rounds up to
two 32-bit registers (8 bytes). nft_meta_bridge_get_eval() then does
memcpy(dest, br_dev->dev_addr, ETH_ALEN), writing only 6 bytes and
leaving the upper 2 bytes of the second register as uninitialised
nft_do_chain() stack. A downstream load of that register span leaks
those stale bytes to userspace.
Zero the second register before the memcpy so the full declared span is
written.
Fixes: cbd2257dc9 ("netfilter: nft_meta_bridge: introduce NFT_META_BRI_IIFHWADDR support")
Cc: [email protected]
Signed-off-by: Davide Ornaghi <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
ebt_redirect_tg() dereferences br_port_get_rcu() return without a
NULL check, causing a kernel panic when the bridge port has been
removed between the original hook invocation and an NFQUEUE
reinject.
A mere NULL check isn't sufficient, however. As sashiko review
points out userspace can not only remove the port from the bridge,
it could also place the device in a different virtual device, e.g.
macvlan.
If this happens, we must drop the packet, there is no way for us to
reinject it into the bridge path.
Switch to _upper API, we don't need the bridge port structure.
Also, this fix keeps another bug intact:
Both nfnetlink_log and nfnetlink_queue use CONFIG_BRIDGE_NETFILTER
too aggressive, which prevents certain logging features when queueing
in bridge family: NETFILTER_FAMILY_BRIDGE can be enabled while the old
CONFIG_BRIDGE_NETFILTER cruft is off.
Fixes tag is a common ancestor, this was always broken.
Fixes: f350a0a873 ("bridge: use rx_handler_data pointer to store net_bridge_port pointer")
Reported-by: Ji'an Zhou <[email protected]>
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
The ebtables SNAT target keeps the Ethernet source address rewrite
behind skb_ensure_writable(skb, 0). This is intentional: at the bridge
ebtables hooks the Ethernet header is addressed through
skb_mac_header()/eth_hdr(), while skb->data points at the Ethernet
payload. Asking skb_ensure_writable() for ETH_HLEN bytes would check
the payload, not the Ethernet header, and would reintroduce the small
packet regression fixed by commit 63137bc588.
However, the optional ARP sender hardware address rewrite is different.
It writes through skb_store_bits() at an offset relative to skb->data:
skb_store_bits(skb, sizeof(struct arphdr), info->mac, ETH_ALEN)
skb_header_pointer() only safely reads the ARP header; it does not make
the later sender hardware address range writable. If that range is
still held in a nonlinear skb fragment backed by a splice-imported file
page, skb_store_bits() maps the frag page and copies the new MAC address
directly into it.
Ensure the ARP SHA range is writable before reading the ARP header and
before calling skb_store_bits().
Fixes: 63137bc588 ("netfilter: ebtables: Fixes dropping of small packets in bridge nat")
Reported-by: Yiming Qian <[email protected]>
Signed-off-by: Yiming Qian <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Similar to a few other subsystems: add a new config toggle to
enable netfilter gcov profiling in netfilter, including ebtables,
arptables and so on.
ipset and ipvs gain their own, dedicated toggles.
Acked-by: Julian Anastasov <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
This feature is required to use 32bit arp/ip/ip6/ebtables binaries on
64bit kernels. I don't think there are many users left.
Support has been a compile-time option since 2021 and defaults to off
since 2023.
The XTABLES_COMPAT config option is already off in many distributions
including Debian and Fedora.
Give a few more months before complete removal but disable support in
user namespaces already.
Assisted-by: Claude:claude-sonnet-4-6
Signed-off-by: Florian Westphal <[email protected]>
Luxiao Xu says:
The function compat_mtw_from_user() converts ebtables extensions from
32-bit user structures to kernel native structures. However, it lacks
proper validation of the user-supplied match_size/target_size.
When certain extensions are processed, the kernel-side translation
logic may perform memory accesses based on the extension's expected
size. If the user provides a size smaller than what the extension
requires, it results in an out-of-bounds read as reported by KASAN.
This fix introduces a check to ensure match_size is at least as large
as the extension's required compatsize. This covers matches, watchers,
and targets, while maintaining compatibility with standard targets.
AFAIU this is relevant for matches that need to go though
match->compat_from_user() call. Those that use plain memcpy with the
user-provided size are ok because the caller checks that size vs the
start of the next rule entry offset (which itself is checked vs. total
size copied from userspace).
The ->compat_from_user() callbacks assume they can read compatsize bytes,
so they need this extra check.
Based on an earlier patch from Luxiao Xu.
Fixes: 81e675c227 ("netfilter: ebtables: add CONFIG_COMPAT support")
Reported-by: Yuan Tan <[email protected]>
Reported-by: Yifan Wu <[email protected]>
Reported-by: Juefei Pu <[email protected]>
Reported-by: Xin Liu <[email protected]>
Signed-off-by: Luxiao Xu <[email protected]>
Signed-off-by: Ren Wei <[email protected]>
Reviewed-by: Fernando Fernandez Mancera <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
sashiko reports for unrelated patch:
Does the core ebtables initialization in ebtables.c suffer from a similar race?
Once nf_register_sockopt() completes, the sockopts are exposed globally.
sockopt has to be registered last, just like in ip/ip6/arptables.
Fixes: 5b53951cfc ("netfilter: ebtables: use net_generic infra")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
sashiko reported for a related patch:
In modules like iptable_raw.c, [..], if register_pernet_subsys() fails,
the rollback might call kfree(rawtable_ops) before [..]
During this window, could a concurrent userspace process find the globally
visible template, trigger table_init(), [..]
The table init functions must always register the template last.
Otherwise, set/getsockopt can instantiate a table in a namespace
while the required pernet ops (contain the destructor) isn't available.
This change is also required in x_tables, handled in followup change.
Fixes: 87663c39f8 ("netfilter: ebtables: do not hook tables by default")
Reviewed-by: Tristan Madani <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Like previous patches for x_tables, follow same pattern in ebtables.
We can't reuse xt helpers: ebt_table struct layout is incompatible.
table->ops assignment is now done while still holding the ebt mutex
to make sure we never expose partially-filled table struct.
Fixes: 87663c39f8 ("netfilter: ebtables: do not hook tables by default")
Reviewed-by: Tristan Madani <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Cross-merge networking fixes after downstream PR (net-7.0-rc2).
Conflicts:
tools/testing/selftests/drivers/net/hw/rss_ctx.py
19c3a2a81d ("selftests: drv-net: rss: Generate unique ports for RSS context tests")
ce5a0f4612 ("selftests: drv-net: rss_ctx: test RSS contexts persist after ifdown/up")
include/net/inet_connection_sock.h
858d2a4f67 ("tcp: fix potential race in tcp_v6_syn_recv_sock()")
fcd3d039fa ("tcp: make tcp_v{4,6}_send_check() static")
https://lore.kernel.org/[email protected]
drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c
drivers/net/ethernet/mellanox/mlx5/core/en/xsk/pool.c
69050f8d6d ("treewide: Replace kmalloc with kmalloc_obj for non-scalar types")
bf4afc53b7 ("Convert 'alloc_obj' family to use the new default GFP_KERNEL argument")
8a96b9144f ("net/mlx5e: Alloc xsk channel param out of mlx5e_open_xsk()")
Adjacent changes:
net/netfilter/ipvs/ip_vs_ctl.c
c59bd9e62e ("ipvs: use more counters to avoid service lookups")
bf4afc53b7 ("Convert 'alloc_obj' family to use the new default GFP_KERNEL argument")
Signed-off-by: Jakub Kicinski <[email protected]>
This facility was disabled in commit
9e539c5b6d ("netfilter: nf_tables: disable expression reduction infra"),
because not all nft_exprs guarantee they will update the destination
register: some may set NFT_BREAK instead to cancel evaluation of the
rule.
This has been dead code ever since.
There are no plans to salvage this at this time, so remove this.
Signed-off-by: Florian Westphal <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <[email protected]>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <[email protected]>
The next commits will transition away from using the hop-by-hop
extension header to encode packet length for BIG TCP. Add wrappers
around ip6->payload_len that return the actual value if it's non-zero,
and calculate it from skb->len if payload_len is set to zero (and a
symmetrical setter).
The new helpers are used wherever the surrounding code supports the
hop-by-hop jumbo header for BIG TCP IPv6, or the corresponding IPv4 code
uses skb_ip_totlen (e.g., in include/net/netfilter/nf_tables_ipv6.h).
No behavioral change in this commit.
Signed-off-by: Alice Mikityanska <[email protected]>
Acked-by: Paolo Abeni <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
The -EEXIST error code is reserved by the module loading infrastructure
to indicate that a module is already loaded. When a module's init
function returns -EEXIST, userspace tools like kmod interpret this as
"module already loaded" and treat the operation as successful, returning
0 to the user even though the module initialization actually failed.
Replace -EEXIST with -EBUSY to ensure correct error reporting in the module
initialization path.
Affected modules:
* ebtable_broute ebtable_filter ebtable_nat arptable_filter
* ip6table_filter ip6table_mangle ip6table_nat ip6table_raw
* ip6table_security iptable_filter iptable_mangle iptable_nat
* iptable_raw iptable_security
Signed-off-by: Daniel Gomez <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Expose the input bridge interface ethernet address so it can be used to
redirect the packet to the receiving physical device for processing.
Tested with nft command line tool.
table bridge nat {
chain PREROUTING {
type filter hook prerouting priority 0; policy accept;
ether daddr de:ad:00:00:be:ef meta pkttype set host ether daddr set meta ibrhwdr accept
}
}
Joint work with Pablo Neira.
Signed-off-by: Fernando Fernandez Mancera <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Remove array_size() calls and replace vmalloc() with vmalloc_array() to
simplify the code. vmalloc_array() is also optimized better, uses fewer
instructions, and handles overflow more concisely[1].
[1]: https://lore.kernel.org/lkml/[email protected]/
Signed-off-by: Qianfeng Rong <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Some Kconfig symbols were changed to depend on the 'bool' symbol
NETFILTER_XTABLES_LEGACY, which means they can now be set to built-in
when the xtables code itself is in a loadable module:
x86_64-linux-ld: vmlinux.o: in function `arpt_unregister_table_pre_exit':
(.text+0x1831987): undefined reference to `xt_find_table'
x86_64-linux-ld: vmlinux.o: in function `get_info.constprop.0':
arp_tables.c:(.text+0x1831aab): undefined reference to `xt_request_find_table_lock'
x86_64-linux-ld: arp_tables.c:(.text+0x1831bea): undefined reference to `xt_table_unlock'
x86_64-linux-ld: vmlinux.o: in function `do_arpt_get_ctl':
arp_tables.c:(.text+0x183205d): undefined reference to `xt_find_table_lock'
x86_64-linux-ld: arp_tables.c:(.text+0x18320c1): undefined reference to `xt_table_unlock'
x86_64-linux-ld: arp_tables.c:(.text+0x183219a): undefined reference to `xt_recseq'
Change these to depend on both NETFILTER_XTABLES and
NETFILTER_XTABLES_LEGACY.
Fixes: 9fce66583f ("netfilter: Exclude LEGACY TABLES on PREEMPT_RT.")
Signed-off-by: Arnd Bergmann <[email protected]>
Acked-by: Florian Westphal <[email protected]>
Tested-by: Breno Leitao <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
The seqcount xt_recseq is used to synchronize the replacement of
xt_table::private in xt_replace_table() against all readers such as
ipt_do_table()
To ensure that there is only one writer, the writing side disables
bottom halves. The sequence counter can be acquired recursively. Only the
first invocation modifies the sequence counter (signaling that a writer
is in progress) while the following (recursive) writer does not modify
the counter.
The lack of a proper locking mechanism for the sequence counter can lead
to live lock on PREEMPT_RT if the high prior reader preempts the
writer. Additionally if the per-CPU lock on PREEMPT_RT is removed from
local_bh_disable() then there is no synchronisation for the per-CPU
sequence counter.
The affected code is "just" the legacy netfilter code which is replaced
by "netfilter tables". That code can be disabled without sacrificing
functionality because everything is provided by the newer
implementation. This will only requires the usage of the "-nft" tools
instead of the "-legacy" ones.
The long term plan is to remove the legacy code so lets accelerate the
progress.
Relax dependencies on iptables legacy, replace select with depends on,
this should cause no harm to existing kernel configs and users can still
toggle IP{6}_NF_IPTABLES_LEGACY in any case.
Make EBTABLES_LEGACY, IPTABLES_LEGACY and ARPTABLES depend on
NETFILTER_XTABLES_LEGACY. Hide xt_recseq and its users,
xt_register_table() and xt_percpu_counter_alloc() behind
NETFILTER_XTABLES_LEGACY. Let NETFILTER_XTABLES_LEGACY depend on
!PREEMPT_RT.
This will break selftest expecing the legacy options enabled and will be
addressed in a following patch.
Co-developed-by: Florian Westphal <[email protected]>
Co-developed-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
The config NF_CONNTRACK_BRIDGE will change the bridge forwarding for
fragmented packets.
The original bridge does not know that it is a fragmented packet and
forwards it directly, after NF_CONNTRACK_BRIDGE is enabled, function
nf_br_ip_fragment and br_ip6_fragment will check the headroom.
In original br_forward, insufficient headroom of skb may indeed exist,
but there's still a way to save the skb in the device driver after
dev_queue_xmit.So droping the skb will change the original bridge
forwarding in some cases.
Fixes: 3c171f496e ("netfilter: bridge: add connection tracking system")
Signed-off-by: Huajian Yang <[email protected]>
Reviewed-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
strncpy() is deprecated for use on NUL-terminated destination strings [1] and
as such we should prefer more robust and less ambiguous string interfaces.
In this particular instance, the usage of strncpy() is fine and works as
expected. However, towards the goal of [2], we should consider replacing
it with an alternative as many instances of strncpy() are bug-prone. Its
removal from the kernel promotes better long term health for the
codebase.
The current usage of strncpy() likely just wants the NUL-padding
behavior offered by strncpy() and doesn't care about the
NUL-termination. Since the compiler doesn't know the size of @dest, we
can't use strtomem_pad(). Instead, use strscpy_pad() which behaves
functionally the same as strncpy() in this context -- as we expect
br_dev->name to be NUL-terminated itself.
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://github.com/KSPP/linux/issues/90 [2]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Cc: Kees Cook <[email protected]>
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
This option makes legacy Netfilter Kconfig user selectable, giving users
the option to configure iptables without enabling any other config.
Make the following KConfig entries user selectable:
* BRIDGE_NF_EBTABLES_LEGACY
* IP_NF_ARPTABLES
* IP_NF_IPTABLES_LEGACY
* IP6_NF_IPTABLES_LEGACY
Signed-off-by: Breno Leitao <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
When we are allocating an array, using kmemdup_array() to take care about
multiplication and possible overflows.
Also it makes auditing the code easier.
Signed-off-by: Yan Zhen <[email protected]>
Reviewed-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
mono_delivery_time was added to check if skb->tstamp has delivery
time in mono clock base (i.e. EDT) otherwise skb->tstamp has
timestamp in ingress and delivery_time at egress.
Renaming the bitfield from mono_delivery_time to tstamp_type is for
extensibilty for other timestamps such as userspace timestamp
(i.e. SO_TXTIME) set via sock opts.
As we are renaming the mono_delivery_time to tstamp_type, it makes
sense to start assigning tstamp_type based on enum defined
in this commit.
Earlier we used bool arg flag to check if the tstamp is mono in
function skb_set_delivery_time, Now the signature of the functions
accepts tstamp_type to distinguish between mono and real time.
Also skb_set_delivery_type_by_clockid is a new function which accepts
clockid to determine the tstamp_type.
In future tstamp_type:1 can be extended to support userspace timestamp
by increasing the bitfield.
Signed-off-by: Abhishek Chauhan <[email protected]>
Reviewed-by: Willem de Bruijn <[email protected]>
Reviewed-by: Martin KaFai Lau <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Martin KaFai Lau <[email protected]>
conntrack nf_confirm logic cannot handle cloned skbs referencing
the same nf_conn entry, which will happen for multicast (broadcast)
frames on bridges.
Example:
macvlan0
|
br0
/ \
ethX ethY
ethX (or Y) receives a L2 multicast or broadcast packet containing
an IP packet, flow is not yet in conntrack table.
1. skb passes through bridge and fake-ip (br_netfilter)Prerouting.
-> skb->_nfct now references a unconfirmed entry
2. skb is broad/mcast packet. bridge now passes clones out on each bridge
interface.
3. skb gets passed up the stack.
4. In macvlan case, macvlan driver retains clone(s) of the mcast skb
and schedules a work queue to send them out on the lower devices.
The clone skb->_nfct is not a copy, it is the same entry as the
original skb. The macvlan rx handler then returns RX_HANDLER_PASS.
5. Normal conntrack hooks (in NF_INET_LOCAL_IN) confirm the orig skb.
The Macvlan broadcast worker and normal confirm path will race.
This race will not happen if step 2 already confirmed a clone. In that
case later steps perform skb_clone() with skb->_nfct already confirmed (in
hash table). This works fine.
But such confirmation won't happen when eb/ip/nftables rules dropped the
packets before they reached the nf_confirm step in postrouting.
Pablo points out that nf_conntrack_bridge doesn't allow use of stateful
nat, so we can safely discard the nf_conn entry and let inet call
conntrack again.
This doesn't work for bridge netfilter: skb could have a nat
transformation. Also bridge nf prevents re-invocation of inet prerouting
via 'sabotage_in' hook.
Work around this problem by explicit confirmation of the entry at LOCAL_IN
time, before upper layer has a chance to clone the unconfirmed entry.
The downside is that this disables NAT and conntrack helpers.
Alternative fix would be to add locking to all code parts that deal with
unconfirmed packets, but even if that could be done in a sane way this
opens up other problems, for example:
-m physdev --physdev-out eth0 -j SNAT --snat-to 1.2.3.4
-m physdev --physdev-out eth1 -j SNAT --snat-to 1.2.3.5
For multicast case, only one of such conflicting mappings will be
created, conntrack only handles 1:1 NAT mappings.
Users should set create a setup that explicitly marks such traffic
NOTRACK (conntrack bypass) to avoid this, but we cannot auto-bypass
them, ruleset might have accept rules for untracked traffic already,
so user-visible behaviour would change.
Suggested-by: Pablo Neira Ayuso <[email protected]>
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217777
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Same patch as previous one, but for ebtables.
To build a kernel that only supports ebtables-nft, the builtin tables
need to be disabled, i.e.:
CONFIG_BRIDGE_EBT_BROUTE=n
CONFIG_BRIDGE_EBT_T_FILTER=n
CONFIG_BRIDGE_EBT_T_NAT=n
The ebtables specific extensions can then be used nftables'
NFT_COMPAT interface.
Signed-off-by: Florian Westphal <[email protected]>
When compiling with gcc 13 and CONFIG_FORTIFY_SOURCE=y, the following
warning appears:
In function ‘fortify_memcpy_chk’,
inlined from ‘size_entry_mwt’ at net/bridge/netfilter/ebtables.c:2118:2:
./include/linux/fortify-string.h:592:25: error: call to ‘__read_overflow2_field’
declared with attribute warning: detected read beyond size of field (2nd parameter);
maybe use struct_group()? [-Werror=attribute-warning]
592 | __read_overflow2_field(q_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The compiler is complaining:
memcpy(&offsets[1], &entry->watchers_offset,
sizeof(offsets) - sizeof(offsets[0]));
where memcpy reads beyong &entry->watchers_offset to copy
{watchers,target,next}_offset altogether into offsets[]. Silence the
warning by wrapping these three up via struct_group().
Signed-off-by: GONG, Ruiqi <[email protected]>
Reviewed-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
nftables equivalent for ebtables -t broute.
Implement broute meta statement to set br_netfilter_broute flag
in skb to force a packet to be routed instead of being bridged.
Signed-off-by: Sriram Yagnaraman <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Fix broken listing of set elements when table has an owner.
2) Fix conntrack refcount leak in ctnetlink with related conntrack
entries, from Hangyu Hua.
3) Fix use-after-free/double-free in ctnetlink conntrack insert path,
from Florian Westphal.
4) Fix ip6t_rpfilter with VRF, from Phil Sutter.
5) Fix use-after-free in ebtables reported by syzbot, also from Florian.
6) Use skb->len in xt_length to deal with IPv6 jumbo packets,
from Xin Long.
7) Fix NETLINK_LISTEN_ALL_NSID with ctnetlink, from Florian Westphal.
8) Fix memleak in {ip_,ip6_,arp_}tables in ENOMEM error case,
from Pavel Tikhomirov.
* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: x_tables: fix percpu counter block leak on error path when creating new netns
netfilter: ctnetlink: make event listener tracking global
netfilter: xt_length: use skb len to match in length_mt6
netfilter: ebtables: fix table blob use-after-free
netfilter: ip6t_rpfilter: Fix regression with VRF interfaces
netfilter: conntrack: fix rmmod double-free race
netfilter: ctnetlink: fix possible refcount leak in ctnetlink_create_conntrack()
netfilter: nf_tables: allow to fetch set elements when table has an owner
====================
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
We are not allowed to return an error at this point.
Looking at the code it looks like ret is always 0 at this
point, but its not.
t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
... this can return a valid table, with ret != 0.
This bug causes update of table->private with the new
blob, but then frees the blob right away in the caller.
Syzbot report:
BUG: KASAN: vmalloc-out-of-bounds in __ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
Read of size 4 at addr ffffc90005425000 by task kworker/u4:4/74
Workqueue: netns cleanup_net
Call Trace:
kasan_report+0xbf/0x1f0 mm/kasan/report.c:517
__ebt_unregister_table+0xc00/0xcd0 net/bridge/netfilter/ebtables.c:1168
ebt_unregister_table+0x35/0x40 net/bridge/netfilter/ebtables.c:1372
ops_exit_list+0xb0/0x170 net/core/net_namespace.c:169
cleanup_net+0x4ee/0xb10 net/core/net_namespace.c:613
...
ip(6)tables appears to be ok (ret should be 0 at this point) but make
this more obvious.
Fixes: c58dd2dd44 ("netfilter: Can't fail and free after table replacement")
Reported-by: [email protected]
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
These 3 places in bridge netfilter are called on RX path after GRO
and IPv4 TCP GSO packets may come through, so replace iph tot_len
accessing with skb_ip_totlen() in there.
Signed-off-by: Xin Long <[email protected]>
Reviewed-by: Nikolay Aleksandrov <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: Jakub Kicinski <[email protected]>
No need to have distinct functions. After merge, ipv6 can avoid
protooff computation if the connection neither needs sequence adjustment
nor helper invocation -- this is the normal case.
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Chengfeng Ye