The expired catchall element is not deactivated and removed from GC sync
path. This path holds mutex so just call nft_setelem_data_deactivate()
and nft_setelem_catchall_remove() before queueing the GC work.
Fixes: 4a9e12ea7e ("netfilter: nft_set_pipapo: call nft_trans_gc_queue_sync() in catchall GC")
Reported-by: lonial con <kongln9170@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Relieve the dump callback from having to check nlmsg_type upon each
call. Prep work for set element reset locking.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Return struct nft_elem_priv instead of struct nft_set_ext for
consistency with ("netfilter: nf_tables: expose opaque set element as
struct nft_elem_priv") and to prepare the introduction of element
timeout updates from control path.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of copying struct nft_set_elem into struct nft_trans_elem, store
the pointer to the opaque set element object in the transaction. Adapt
set backend API (and set backend implementations) to take the pointer to
opaque set element representation whenever required.
This patch deconstifies .remove() and .activate() set backend API since
these modify the set element opaque object. And it also constify
nft_set_elem_ext() this provides access to the nft_set_ext struct
without updating the object.
According to pahole on x86_64, this patch shrinks struct nft_trans_elem
size from 216 to 24 bytes.
This patch also reduces stack memory consumption by removing the
template struct nft_set_elem object, using the opaque set element object
instead such as from the set iterator API, catchall elements and the get
element command.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add placeholder structure and place it at the beginning of each struct
nft_*_elem for each existing set backend, instead of exposing elements
as void type to the frontend which defeats compiler type checks. Use
this pointer to this new type to replace void *.
This patch updates the following set backend API to use this new struct
nft_elem_priv placeholder structure:
- update
- deactivate
- flush
- get
as well as the following helper functions:
- nft_set_elem_ext()
- nft_set_elem_init()
- nft_set_elem_destroy()
- nf_tables_set_elem_destroy()
This patch adds nft_elem_priv_cast() to cast struct nft_elem_priv to
native element representation from the corresponding set backend.
BUILD_BUG_ON() makes sure this .priv placeholder is always at the top
of the opaque set element representation.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
.flush is always successful since this results from iterating over the
set elements to toggle mark the element as inactive in the next
generation.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Relieve the dump callback from having to inspect nlmsg_type upon each
call, just do it once at start of the dump.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
No need to allocate it if one may just use struct netlink_callback's
scratch area for it.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Prep work for moving the context into struct netlink_callback scratch
area.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Name it for what it is supposed to become, a real nft_obj_dump_ctx. No
functional change intended.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Prep work for moving the filter into struct netlink_callback's scratch
area.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The code does not make use of cb->args fields past the first one, no
need to zero them.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Rule reset is not concurrency-safe per-se, so multiple CPUs may reset
the same rule at the same time. At least counter and quota expressions
will suffer from value underruns in this case.
Prevent this by introducing dedicated locking callbacks for nfnetlink
and the asynchronous dump handling to serialize access.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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>
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>
nf_tables_abort_release() path calls nft_set_elem_destroy() for
NFT_MSG_NEWSETELEM which releases the element, however, a reference to
the element still remains in the working copy.
Fixes: ebd032fa88 ("netfilter: nf_tables: do not remove elements if set backend implements .abort")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
When resetting multiple objects at once (via dump request), emit a log
message per table (or filled skb) and resurrect the 'entries' parameter
to contain the number of objects being logged for.
To test the skb exhaustion path, perform some bulk counter and quota
adds in the kselftest.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com> (Audit)
Signed-off-by: Florian Westphal <fw@strlen.de>
The dump and reset command should not refresh the timeout, this command
is intended to allow users to list existing stateful objects and reset
them, element expiration should be refresh via transaction instead with
a specific command to achieve this, otherwise this is entering combo
semantics that will be hard to be undone later (eg. a user asking to
retrieve counters but _not_ requiring to refresh expiration).
Fixes: 079cd63321 ("netfilter: nf_tables: Introduce NFT_MSG_GETSETELEM_RESET")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
pipapo set backend maintains two copies of the datastructure, removing
the elements from the copy that is going to be discarded slows down
the abort path significantly, from several minutes to few seconds after
this patch.
Fixes: 212ed75dc5 ("netfilter: nf_tables: integrate pipapo into commit protocol")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Since struct netlink_callback::args is not used by rule dumpers anymore,
use it to hold nft_rule_dump_ctx. Add a build-time check to make sure it
won't ever exceed the available space.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
In order to move the context into struct netlink_callback's scratch
area, the latter must be unused first.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
This relieves the dump callback from having to check nlmsg_type upon
each call and instead performs the check once in .start callback.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
None of the dump callbacks uses netlink_callback::args beyond the first
element, no need to zero the data.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
It will move into struct netlink_callback's scratch area later, just put
nf_tables_dump_rules_start in shape to reduce churn later.
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
When adding/updating an object, the transaction handler emits suitable
audit log entries already, the one in nft_obj_notify() is redundant. To
fix that (and retain the audit logging from objects' 'update' callback),
Introduce an "audit log free" variant for internal use.
Fixes: c520292f29 ("audit: log nftables configuration change events once per table")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com> (Audit)
Signed-off-by: Florian Westphal <fw@strlen.de>
Mark attributes which are supposed to be arrays of nested attributes
with known content as such. Originally suggested for
NFTA_RULE_EXPRESSIONS only, but does apply to others as well.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
Set netlink extended error reporting for several lookup functions which
allows userspace to infer what is the error cause.
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
When more than 255 elements expired we're supposed to switch to a new gc
container structure.
This never happens: u8 type will wrap before reaching the boundary
and nft_trans_gc_space() always returns true.
This means we recycle the initial gc container structure and
lose track of the elements that came before.
While at it, don't deref 'gc' after we've passed it to call_rcu.
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
nft -f -<<EOF
add table ip t
add table ip t { flags dormant; }
add chain ip t c { type filter hook input priority 0; }
add table ip t
EOF
Triggers a splat from nf core on next table delete because we lose
track of right hook register state:
WARNING: CPU: 2 PID: 1597 at net/netfilter/core.c:501 __nf_unregister_net_hook
RIP: 0010:__nf_unregister_net_hook+0x41b/0x570
nf_unregister_net_hook+0xb4/0xf0
__nf_tables_unregister_hook+0x160/0x1d0
[..]
The above should have table in *active* state, but in fact no
hooks were registered.
Reject on/off/on games rather than attempting to fix this.
Fixes: 179d9ba555 ("netfilter: nf_tables: fix table flag updates")
Reported-by: "Lee, Cherie-Anne" <cherie.lee@starlabs.sg>
Cc: Bing-Jhong Billy Jheng <billy@starlabs.sg>
Cc: info@starlabs.sg
Signed-off-by: Florian Westphal <fw@strlen.de>
The value in idx and the number of rules handled in that particular
__nf_tables_dump_rules() call is not identical. The former is a cursor
to pick up from if multiple netlink messages are needed, so its value is
ever increasing. Fixing this is not just a matter of subtracting s_idx
from it, though: When resetting rules in multiple chains,
__nf_tables_dump_rules() is called for each and cb->args[0] is not
adjusted in between. Introduce a dedicated counter to record the number
of rules reset in this call in a less confusing way.
While being at it, prevent the direct return upon buffer exhaustion: Any
rules previously dumped into that skb would evade audit logging
otherwise.
Fixes: 9b5ba5c9c5 ("netfilter: nf_tables: Unbreak audit log reset")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Anonymous sets need to be populated once at creation and then they are
bound to rule since 938154b93b ("netfilter: nf_tables: reject unbound
anonymous set before commit phase"), otherwise transaction reports
EINVAL.
Userspace does not need to delete elements of anonymous sets that are
not yet bound, reject this with EOPNOTSUPP.
From flush command path, skip anonymous sets, they are expected to be
bound already. Otherwise, EINVAL is hit at the end of this transaction
for unbound sets.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
pipapo needs to enqueue GC transactions for catchall elements through
nft_trans_gc_queue_sync(). Add nft_trans_gc_catchall_sync() and
nft_trans_gc_catchall_async() to handle GC transaction queueing
accordingly.
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Fixes: f6c383b8c3 ("netfilter: nf_tables: adapt set backend to use GC transaction API")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Chain binding only requires the rule addition/insertion command within
the same transaction. Removal of rules from chain bindings within the
same transaction makes no sense, userspace does not utilize this
feature. Replace nft_chain_is_bound() check to nft_chain_binding() in
rule deletion commands. Replace command implies a rule deletion, reject
this command too.
Rule flush command can also safely rely on this nft_chain_binding()
check because unbound chains are not allowed since 62e1e94b24
("netfilter: nf_tables: reject unbound chain set before commit phase").
Fixes: d0e2c7de92 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: Kevin Rich <kevinrich1337@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Resetting rules' stateful data happens outside of the transaction logic,
so 'get' and 'dump' handlers have to emit audit log entries themselves.
Fixes: 8daa8fde3f ("netfilter: nf_tables: Introduce NFT_MSG_GETRULE_RESET")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since set element reset is not integrated into nf_tables' transaction
logic, an explicit log call is needed, similar to NFT_MSG_GETOBJ_RESET
handling.
For the sake of simplicity, catchall element reset will always generate
a dedicated log entry. This relieves nf_tables_dump_set() from having to
adjust the logged element count depending on whether a catchall element
was found or not.
Fixes: 079cd63321 ("netfilter: nf_tables: Introduce NFT_MSG_GETSETELEM_RESET")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use nf_tables_gc_list_lock spinlock, not nf_tables_destroy_list_lock to
protect the gc list.
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Abort path is missing a synchronization point with GC transactions. Add
GC sequence number hence any GC transaction losing race will be
discarded.
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Destroy work waits for the RCU grace period then it releases the objects
with no mutex held. All releases objects follow this path for
transactions, therefore, order is guaranteed and references to top-level
objects in the hierarchy remain valid.
However, netlink notifier might interfer with pending destroy work.
rcu_barrier() is not correct because objects are not release via RCU
callback. Flush destroy work before releasing objects from netlink
notifier path.
Fixes: d4bc8271db ("netfilter: nf_tables: netlink notifier might race to release objects")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
We have to validate all tables in the transaction that are in
VALIDATE_DO state, the blamed commit below did not move the break
statement to its right location so we only validate one table.
Moreover, we can't init table->validate to _SKIP when a table object
is allocated.
If we do, then if a transcaction creates a new table and then
fails the transaction, nfnetlink will loop and nft will hang until
user cancels the command.
Add back the pernet state as a place to stash the last state encountered.
This is either _DO (we hit an error during commit validation) or _SKIP
(transaction passed all checks).
Fixes: 00c320f9b7 ("netfilter: nf_tables: make validation state per table")
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
abort early so task can exit faster if a fatal signal is pending,
no need to continue validation in that case.
Signed-off-by: Florian Westphal <fw@strlen.de>
Use maybe_get_net() since GC workqueue might race with netns exit path.
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Netlink event path is missing a synchronization point with GC
transactions. Add GC sequence number update to netns release path and
netlink event path, any GC transaction losing race will be discarded.
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
When flushing, individual set elements are disabled in the next
generation via the ->flush callback.
Catchall elements are not disabled. This is incorrect and may lead to
double-deactivations of catchall elements which then results in memory
leaks:
WARNING: CPU: 1 PID: 3300 at include/net/netfilter/nf_tables.h:1172 nft_map_deactivate+0x549/0x730
CPU: 1 PID: 3300 Comm: nft Not tainted 6.5.0-rc5+ #60
RIP: 0010:nft_map_deactivate+0x549/0x730
[..]
? nft_map_deactivate+0x549/0x730
nf_tables_delset+0xb66/0xeb0
(the warn is due to nft_use_dec() detecting underflow).
Fixes: aaa31047a6 ("netfilter: nftables: add catch-all set element support")
Reported-by: lonial con <kongln9170@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Use the GC transaction API to replace the old and buggy gc API and the
busy mark approach.
No set elements are removed from async garbage collection anymore,
instead the _DEAD bit is set on so the set element is not visible from
lookup path anymore. Async GC enqueues transaction work that might be
aborted and retried later.
rbtree and pipapo set backends does not set on the _DEAD bit from the
sync GC path since this runs in control plane path where mutex is held.
In this case, set elements are deactivated, removed and then released
via RCU callback, sync GC never fails.
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Fixes: 8d8540c4f5 ("netfilter: nft_set_rbtree: add timeout support")
Fixes: 9d0982927e ("netfilter: nft_hash: add support for timeouts")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The set types rhashtable and rbtree use a GC worker to reclaim memory.
From system work queue, in periodic intervals, a scan of the table is
done.
The major caveat here is that the nft transaction mutex is not held.
This causes a race between control plane and GC when they attempt to
delete the same element.
We cannot grab the netlink mutex from the work queue, because the
control plane has to wait for the GC work queue in case the set is to be
removed, so we get following deadlock:
cpu 1 cpu2
GC work transaction comes in , lock nft mutex
`acquire nft mutex // BLOCKS
transaction asks to remove the set
set destruction calls cancel_work_sync()
cancel_work_sync will now block forever, because it is waiting for the
mutex the caller already owns.
This patch adds a new API that deals with garbage collection in two
steps:
1) Lockless GC of expired elements sets on the NFT_SET_ELEM_DEAD_BIT
so they are not visible via lookup. Annotate current GC sequence in
the GC transaction. Enqueue GC transaction work as soon as it is
full. If ruleset is updated, then GC transaction is aborted and
retried later.
2) GC work grabs the mutex. If GC sequence has changed then this GC
transaction lost race with control plane, abort it as it contains
stale references to objects and let GC try again later. If the
ruleset is intact, then this GC transaction deactivates and removes
the elements and it uses call_rcu() to destroy elements.
Note that no elements are removed from GC lockless path, the _DEAD bit
is set and pointers are collected. GC catchall does not remove the
elements anymore too. There is a new set->dead flag that is set on to
abort the GC transaction to deal with set->ops->destroy() path which
removes the remaining elements in the set from commit_release, where no
mutex is held.
To deal with GC when mutex is held, which allows safe deactivate and
removal, add sync GC API which releases the set element object via
call_rcu(). This is used by rbtree and pipapo backends which also
perform garbage collection from control plane path.
Since element removal from sets can happen from control plane and
element garbage collection/timeout, it is necessary to keep the set
structure alive until all elements have been deactivated and destroyed.
We cannot do a cancel_work_sync or flush_work in nft_set_destroy because
its called with the transaction mutex held, but the aforementioned async
work queue might be blocked on the very mutex that nft_set_destroy()
callchain is sitting on.
This gives us the choice of ABBA deadlock or UaF.
To avoid both, add set->refs refcount_t member. The GC API can then
increment the set refcount and release it once the elements have been
free'd.
Set backends are adapted to use the GC transaction API in a follow up
patch entitled:
("netfilter: nf_tables: use gc transaction API in set backends")
This is joint work with Florian Westphal.
Fixes: cfed7e1b1f ("netfilter: nf_tables: add set garbage collection helpers")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
There is an asymmetry between commit/abort and preparation phase if the
following conditions are met:
1. set is a verdict map ("1.2.3.4 : jump foo")
2. timeouts are enabled
In this case, following sequence is problematic:
1. element E in set S refers to chain C
2. userspace requests removal of set S
3. kernel does a set walk to decrement chain->use count for all elements
from preparation phase
4. kernel does another set walk to remove elements from the commit phase
(or another walk to do a chain->use increment for all elements from
abort phase)
If E has already expired in 1), it will be ignored during list walk, so its use count
won't have been changed.
Then, when set is culled, ->destroy callback will zap the element via
nf_tables_set_elem_destroy(), but this function is only safe for
elements that have been deactivated earlier from the preparation phase:
lack of earlier deactivate removes the element but leaks the chain use
count, which results in a WARN splat when the chain gets removed later,
plus a leak of the nft_chain structure.
Update pipapo_get() not to skip expired elements, otherwise flush
command reports bogus ENOENT errors.
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Fixes: 8d8540c4f5 ("netfilter: nft_set_rbtree: add timeout support")
Fixes: 9d0982927e ("netfilter: nft_hash: add support for timeouts")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Bail out with EOPNOTSUPP when adding rule to bound chain via
NFTA_RULE_CHAIN_ID. The following warning splat is shown when
adding a rule to a deleted bound chain:
WARNING: CPU: 2 PID: 13692 at net/netfilter/nf_tables_api.c:2013 nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]
CPU: 2 PID: 13692 Comm: chain-bound-rul Not tainted 6.1.39 #1
RIP: 0010:nf_tables_chain_destroy+0x1f7/0x210 [nf_tables]
Fixes: d0e2c7de92 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Reported-by: Kevin Rich <kevinrich1337@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Can be called via nft set element list iteration, which may acquire
rcu and/or bh read lock (depends on set type).
BUG: sleeping function called from invalid context at net/netfilter/nf_tables_api.c:3353
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1232, name: nft
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
2 locks held by nft/1232:
#0: ffff8881180e3ea8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid
#1: ffffffff83f5f540 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire
Call Trace:
nft_chain_validate
nft_lookup_validate_setelem
nft_pipapo_walk
nft_lookup_validate
nft_chain_validate
nft_immediate_validate
nft_chain_validate
nf_tables_validate
nf_tables_abort
No choice but to move it to nf_tables_validate().
Fixes: 81ea010667 ("netfilter: nf_tables: add rescheduling points during loop detection walks")
Signed-off-by: Florian Westphal <fw@strlen.de>
On some platforms there is a padding hole in the nft_verdict
structure, between the verdict code and the chain pointer.
On element insertion, if the new element clashes with an existing one and
NLM_F_EXCL flag isn't set, we want to ignore the -EEXIST error as long as
the data associated with duplicated element is the same as the existing
one. The data equality check uses memcmp.
For normal data (NFT_DATA_VALUE) this works fine, but for NFT_DATA_VERDICT
padding area leads to spurious failure even if the verdict data is the
same.
This then makes the insertion fail with 'already exists' error, even
though the new "key : data" matches an existing entry and userspace
told the kernel that it doesn't want to receive an error indication.
Fixes: c016c7e45d ("netfilter: nf_tables: honor NLM_F_EXCL flag in set element insertion")
Signed-off-by: Florian Westphal <fw@strlen.de>
Overflow use refcount checks are not complete.
Add helper function to deal with object reference counter tracking.
Report -EMFILE in case UINT_MAX is reached.
nft_use_dec() splats in case that reference counter underflows,
which should not ever happen.
Add nft_use_inc_restore() and nft_use_dec_restore() which are used
to restore reference counter from error and abort paths.
Use u32 in nft_flowtable and nft_object since helper functions cannot
work on bitfields.
Remove the few early incomplete checks now that the helper functions
are in place and used to check for refcount overflow.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
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Merge tag 'nf-next-23-06-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next
Pablo Neira Ayuso says:
====================
Netfilter/IPVS updates for net-next
1) Allow slightly larger IPVS connection table size from Kconfig for
64-bit arch, from Abhijeet Rastogi.
2) Since IPVS connection table might be larger than 2^20 after previous
patch, allow to limit it depending on the available memory.
Moreover, use kvmalloc. From Julian Anastasov.
3) Do not rebuild VLAN header in nft_payload when matching source and
destination MAC address.
4) Remove nested rcu read lock side in ip_set_test(), from Florian Westphal.
5) Allow to update set size, also from Florian.
6) Improve NAT tuple selection when connection is closing,
from Florian Westphal.
7) Support for resetting set element stateful expression, from Phil Sutter.
8) Use NLA_POLICY_MAX to narrow down maximum attribute value in nf_tables,
from Florian Westphal.
* tag 'nf-next-23-06-26' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
netfilter: nf_tables: limit allowed range via nla_policy
netfilter: nf_tables: Introduce NFT_MSG_GETSETELEM_RESET
netfilter: snat: evict closing tcp entries on reply tuple collision
netfilter: nf_tables: permit update of set size
netfilter: ipset: remove rcu_read_lock_bh pair from ip_set_test
netfilter: nft_payload: rebuild vlan header when needed
ipvs: dynamically limit the connection hash table
ipvs: increase ip_vs_conn_tab_bits range for 64BIT
====================
Link: https://lore.kernel.org/r/20230626064749.75525-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Set element addition error path decrements reference counter on chains
twice: once on element release and again via nft_data_release().
Then, d6b478666f ("netfilter: nf_tables: fix underflow in object
reference counter") incorrectly fixed this by removing the stateful
object reference count decrement.
Restore the stateful object decrement as in b91d903688 ("netfilter:
nf_tables: fix leaking object reference count") and let
nft_data_release() decrement the chain reference counter, so this is
done only once.
Fixes: d6b478666f ("netfilter: nf_tables: fix underflow in object reference counter")
Fixes: 628bd3e49c ("netfilter: nf_tables: drop map element references from preparation phase")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Otherwise a dangling reference to a rule object that is gone remains
in the set binding list.
Fixes: 26b5a5712e ("netfilter: nf_tables: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Analogous to NFT_MSG_GETOBJ_RESET, but for set elements with a timeout
or attached stateful expressions like counters or quotas - reset them
all at once. Respect a per element timeout value if present to reset the
'expires' value to.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Now that set->nelems is always updated permit update of the sets max size.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When deleting a base chain, iptables-nft simply submits the whole chain
to the kernel, including the NFTA_CHAIN_HOOK attribute. The new code
added by fixed commit then turned this into a chain update, destroying
the hook but not the chain itself. Detect the situation by checking if
the chain type is either netdev or inet/ingress.
Fixes: 7d937b1071 ("netfilter: nf_tables: support for deleting devices in an existing netdev chain")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Otherwise the module reference counter is leaked.
Fixes b9703ed44f ("netfilter: nf_tables: support for adding new devices to an existing netdev chain")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Disallow updates of set timeout and garbage collection parameters for
anonymous sets.
Fixes: 123b99619c ("netfilter: nf_tables: honor set timeout and garbage collection updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Use binding list to track set transaction and to check for unbound
chains before entering the commit phase.
Bail out if chain binding remain unused before entering the commit
step.
Fixes: d0e2c7de92 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new list to track set transaction and to check for unbound
anonymous sets before entering the commit phase.
Bail out at the end of the transaction handling if an anonymous set
remains unbound.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Anonymous sets come with NFT_SET_CONSTANT from userspace. Although API
allows to create anonymous sets without NFT_SET_CONSTANT, it makes no
sense to allow to add and to delete elements for bound anonymous sets.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since ("netfilter: nf_tables: drop map element references from
preparation phase"), integration with commit protocol is better,
therefore drop the workaround that b91d903688 ("netfilter: nf_tables:
fix leaking object reference count") provides.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
set .destroy callback releases the references to other objects in maps.
This is very late and it results in spurious EBUSY errors. Drop refcount
from the preparation phase instead, update set backend not to drop
reference counter from set .destroy path.
Exceptions: NFT_TRANS_PREPARE_ERROR does not require to drop the
reference counter because the transaction abort path releases the map
references for each element since the set is unbound. The abort path
also deals with releasing reference counter for new elements added to
unbound sets.
Fixes: 591054469b ("netfilter: nf_tables: revisit chain/object refcounting from elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a new state to deal with rule expressions deactivation from the
newrule error path, otherwise the anonymous set remains in the list in
inactive state for the next generation. Mark the set/chain transaction
as unbound so the abort path releases this object, set it as inactive in
the next generation so it is not reachable anymore from this transaction
and reference counter is dropped.
Fixes: 1240eb93f0 ("netfilter: nf_tables: incorrect error path handling with NFT_MSG_NEWRULE")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add bound flag to rule and chain transactions as in 6a0a8d10a3
("netfilter: nf_tables: use-after-free in failing rule with bound set")
to skip them in case that the chain is already bound from the abort
path.
This patch fixes an imbalance in the chain use refcnt that triggers a
WARN_ON on the table and chain destroy path.
This patch also disallows nested chain bindings, which is not
supported from userspace.
The logic to deal with chain binding in nft_data_hold() and
nft_data_release() is not correct. The NFT_TRANS_PREPARE state needs a
special handling in case a chain is bound but next expressions in the
same rule fail to initialize as described by 1240eb93f0 ("netfilter:
nf_tables: incorrect error path handling with NFT_MSG_NEWRULE").
The chain is left bound if rule construction fails, so the objects
stored in this chain (and the chain itself) are released by the
transaction records from the abort path, follow up patch ("netfilter:
nf_tables: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain")
completes this error handling.
When deleting an existing rule, chain bound flag is set off so the
rule expression .destroy path releases the objects.
Fixes: d0e2c7de92 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In case of error when adding a new rule that refers to an anonymous set,
deactivate expressions via NFT_TRANS_PREPARE state, not NFT_TRANS_RELEASE.
Thus, the lookup expression marks anonymous sets as inactive in the next
generation to ensure it is not reachable in this transaction anymore and
decrement the set refcount as introduced by c1592a8994 ("netfilter:
nf_tables: deactivate anonymous set from preparation phase"). The abort
step takes care of undoing the anonymous set.
This is also consistent with rule deletion, where NFT_TRANS_PREPARE is
used. Note that this error path is exercised in the preparation step of
the commit protocol. This patch replaces nf_tables_rule_release() by the
deactivate and destroy calls, this time with NFT_TRANS_PREPARE.
Due to this incorrect error handling, it is possible to access a
dangling pointer to the anonymous set that remains in the transaction
list.
[1009.379054] BUG: KASAN: use-after-free in nft_set_lookup_global+0x147/0x1a0 [nf_tables]
[1009.379106] Read of size 8 at addr ffff88816c4c8020 by task nft-rule-add/137110
[1009.379116] CPU: 7 PID: 137110 Comm: nft-rule-add Not tainted 6.4.0-rc4+ #256
[1009.379128] Call Trace:
[1009.379132] <TASK>
[1009.379135] dump_stack_lvl+0x33/0x50
[1009.379146] ? nft_set_lookup_global+0x147/0x1a0 [nf_tables]
[1009.379191] print_address_description.constprop.0+0x27/0x300
[1009.379201] kasan_report+0x107/0x120
[1009.379210] ? nft_set_lookup_global+0x147/0x1a0 [nf_tables]
[1009.379255] nft_set_lookup_global+0x147/0x1a0 [nf_tables]
[1009.379302] nft_lookup_init+0xa5/0x270 [nf_tables]
[1009.379350] nf_tables_newrule+0x698/0xe50 [nf_tables]
[1009.379397] ? nf_tables_rule_release+0xe0/0xe0 [nf_tables]
[1009.379441] ? kasan_unpoison+0x23/0x50
[1009.379450] nfnetlink_rcv_batch+0x97c/0xd90 [nfnetlink]
[1009.379470] ? nfnetlink_rcv_msg+0x480/0x480 [nfnetlink]
[1009.379485] ? __alloc_skb+0xb8/0x1e0
[1009.379493] ? __alloc_skb+0xb8/0x1e0
[1009.379502] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0
[1009.379509] ? unwind_get_return_address+0x2a/0x40
[1009.379517] ? write_profile+0xc0/0xc0
[1009.379524] ? avc_lookup+0x8f/0xc0
[1009.379532] ? __rcu_read_unlock+0x43/0x60
Fixes: 958bee14d0 ("netfilter: nf_tables: use new transaction infrastructure to handle sets")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Cross-merge networking fixes after downstream PR.
Conflicts:
net/sched/sch_taprio.c
d636fc5dd6 ("net: sched: add rcu annotations around qdisc->qdisc_sleeping")
dced11ef84 ("net/sched: taprio: don't overwrite "sch" variable in taprio_dump_class_stats()")
net/ipv4/sysctl_net_ipv4.c
e209fee411 ("net/ipv4: ping_group_range: allow GID from 2147483648 to 4294967294")
ccce324dab ("tcp: make the first N SYN RTO backoffs linear")
https://lore.kernel.org/all/20230605100816.08d41a7b@canb.auug.org.au/
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The pipapo set backend follows copy-on-update approach, maintaining one
clone of the existing datastructure that is being updated. The clone
and current datastructures are swapped via rcu from the commit step.
The existing integration with the commit protocol is flawed because
there is no operation to clean up the clone if the transaction is
aborted. Moreover, the datastructure swap happens on set element
activation.
This patch adds two new operations for sets: commit and abort, these new
operations are invoked from the commit and abort steps, after the
transactions have been digested, and it updates the pipapo set backend
to use it.
This patch adds a new ->pending_update field to sets to maintain a list
of sets that require this new commit and abort operations.
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add current size of rule expressions to the boundary check.
Fixes: 2c865a8a28 ("netfilter: nf_tables: add rule blob layout")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The nla_nest_start_noflag() function may fail and return NULL;
the return value needs to be checked.
Found by InfoTeCS on behalf of Linux Verification Center
(linuxtesting.org) with SVACE.
Fixes: d54725cd11 ("netfilter: nf_tables: support for multiple devices per netdev hook")
Signed-off-by: Gavrilov Ilia <Ilia.Gavrilov@infotecs.ru>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Conflicts:
drivers/net/ethernet/freescale/fec_main.c
6ead9c98ca ("net: fec: remove the xdp_return_frame when lack of tx BDs")
144470c88c ("net: fec: using the standard return codes when xdp xmit errors")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
At this time, set->nelems counter only increments when the set has
a maximum size.
All set elements decrement the counter unconditionally, this is
confusing.
Increment the counter unconditionally to make this symmetrical.
This would also allow changing the set maximum size after set creation
in a later patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
nft_trans_FOO objects all share a common nft_trans base structure, but
trailing fields depend on the real object size. Access is only safe after
trans->msg_type check.
Check for rule type first. Found by code inspection.
Fixes: 1a94e38d25 ("netfilter: nf_tables: add NFTA_RULE_ID attribute")
Signed-off-by: Florian Westphal <fw@strlen.de>
Toggle deleted anonymous sets as inactive in the next generation, so
users cannot perform any update on it. Clear the generation bitmask
in case the transaction is aborted.
The following KASAN splat shows a set element deletion for a bound
anonymous set that has been already removed in the same transaction.
[ 64.921510] ==================================================================
[ 64.923123] BUG: KASAN: wild-memory-access in nf_tables_commit+0xa24/0x1490 [nf_tables]
[ 64.924745] Write of size 8 at addr dead000000000122 by task test/890
[ 64.927903] CPU: 3 PID: 890 Comm: test Not tainted 6.3.0+ #253
[ 64.931120] Call Trace:
[ 64.932699] <TASK>
[ 64.934292] dump_stack_lvl+0x33/0x50
[ 64.935908] ? nf_tables_commit+0xa24/0x1490 [nf_tables]
[ 64.937551] kasan_report+0xda/0x120
[ 64.939186] ? nf_tables_commit+0xa24/0x1490 [nf_tables]
[ 64.940814] nf_tables_commit+0xa24/0x1490 [nf_tables]
[ 64.942452] ? __kasan_slab_alloc+0x2d/0x60
[ 64.944070] ? nf_tables_setelem_notify+0x190/0x190 [nf_tables]
[ 64.945710] ? kasan_set_track+0x21/0x30
[ 64.947323] nfnetlink_rcv_batch+0x709/0xd90 [nfnetlink]
[ 64.948898] ? nfnetlink_rcv_msg+0x480/0x480 [nfnetlink]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If user does not specify hook number and priority, then assume this is
a chain/flowtable update. Therefore, report ENOENT which provides a
better hint than EINVAL. Set on extended netlink error report to refer
to the chain name.
Fixes: 5b6743fb2c ("netfilter: nf_tables: skip flowtable hooknum and priority on device updates")
Fixes: 5efe72698a97 ("netfilter: nf_tables: support for adding new devices to an existing netdev chain")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Relax netdev chain creation to allow for loading the ruleset, then
adding/deleting devices at a later stage. Hardware offload does not
support for this feature yet.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Rename nft_flowtable_hooks_destroy() by nft_hooks_destroy() to prepare
for netdev chain device updates.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In most cases, table, name and handle is sufficient for userspace to
identify an object that has been deleted. Skipping unneeded fields in
the netlink attributes in the message saves bandwidth (ie. less chances
of hitting ENOBUFS).
Rules are an exception: the existing userspace monitor code relies on
the rule definition. This exception can be removed by implementing a
rule cache in userspace, this is already supported by the tracing
infrastructure.
Regarding flowtables, incremental deletion of devices is possible.
Skipping a full notification allows userspace to differentiate between
flowtable removal and incremental removal of devices.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Flowtable and netdev chains are bound to one or several netdevice,
extend netlink error reporting to specify the the netdevice that
triggers the error.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We only need to validate tables that saw changes in the current
transaction.
The existing code revalidates all tables, but this isn't needed as
cross-table jumps are not allowed (chains have table scope).
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The ->cleanup callback needs to be removed, this doesn't work anymore as
the transaction mutex is already released in the ->abort function.
Just do it after a successful validation pass, this either happens
from commit or abort phases where transaction mutex is held.
Fixes: f102d66b33 ("netfilter: nf_tables: use dedicated mutex to guard transactions")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Now that the rule trailer/end marker and the rcu head reside in the
same structure, we no longer need to save/restore the chain pointer
when performing/returning from a jump.
We can simply let the trace infra walk the evaluated rule until it
hits the end marker and then fetch the chain pointer from there.
When the rule is NULL (policy tracing), then chain and basechain
pointers were already identical, so just use the basechain.
This cuts size of jumpstack in half, from 256 to 128 bytes in 64bit,
scripts/stackusage says:
nf_tables_core.c:251 nft_do_chain 328 static
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In order to free the rules in a chain via call_rcu, the rule array used
to stash a rcu_head and space for a pointer at the end of the rule array.
When the current nft_rule_dp blob format got added in
2c865a8a28 ("netfilter: nf_tables: add rule blob layout"), this results
in a double-trailer:
size (unsigned long)
struct nft_rule_dp
struct nft_expr
...
struct nft_rule_dp
struct nft_expr
...
struct nft_rule_dp (is_last=1) // Trailer
The trailer, struct nft_rule_dp (is_last=1), is not accounted for in size,
so it can be located via start_addr + size.
Because the rcu_head is stored after 'start+size' as well this means the
is_last trailer is *aliased* to the rcu_head (struct nft_rules_old).
This is harmless, because at this time the nft_do_chain function never
evaluates/accesses the trailer, it only checks the address boundary:
for (; rule < last_rule; rule = nft_rule_next(rule)) {
...
But this way the last_rule address has to be stashed in the jump
structure to restore it after returning from a chain.
nft_do_chain stack usage has become way too big, so put it on a diet.
Without this patch is impossible to use
for (; !rule->is_last; rule = nft_rule_next(rule)) {
... because on free, the needed update of the rcu_head will clobber the
nft_rule_dp is_last bit.
Furthermore, also stash the chain pointer in the trailer, this allows
to recover the original chain structure from nf_tables_trace infra
without a need to place them in the jump struct.
After this patch it is trivial to diet the jump stack structure,
done in the next two patches.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If NFT_SET_ELEM_CATCHALL is set on, then userspace provides no set element
key. Otherwise, bail out with -EINVAL.
Fixes: aaa31047a6 ("netfilter: nftables: add catch-all set element support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso