commit 1bc83a019b upstream.
Hook unregistration is deferred to the commit phase, same occurs with
hook updates triggered by the table dormant flag. When both commands are
combined, this results in deleting a basechain while leaving its hook
still registered in the core.
Fixes: 179d9ba555 ("netfilter: nf_tables: fix table flag updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 552705a365 upstream.
While the rhashtable set gc runs asynchronously, a race allows it to
collect elements from anonymous sets with timeouts while it is being
released from the commit path.
Mingi Cho originally reported this issue in a different path in 6.1.x
with a pipapo set with low timeouts which is not possible upstream since
7395dfacff ("netfilter: nf_tables: use timestamp to check for set
element timeout").
Fix this by setting on the dead flag for anonymous sets to skip async gc
in this case.
According to 08e4c8c591 ("netfilter: nf_tables: mark newset as dead on
transaction abort"), Florian plans to accelerate abort path by releasing
objects via workqueue, therefore, this sets on the dead flag for abort
path too.
Cc: stable@vger.kernel.org
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Reported-by: Mingi Cho <mgcho.minic@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit bccebf6470 ]
We need to set the dormant flag again if we fail to register
the hooks.
During memory pressure hook registration can fail and we end up
with a table marked as active but no registered hooks.
On table/base chain deletion, nf_tables will attempt to unregister
the hook again which yields a warn splat from the nftables core.
Reported-and-tested-by: syzbot+de4025c006ec68ac56fc@syzkaller.appspotmail.com
Fixes: 179d9ba555 ("netfilter: nf_tables: fix table flag updates")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 6b1ca88e4b ]
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: 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: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 08e4c8c591 ]
If a transaction is aborted, we should mark the to-be-released NEWSET dead,
just like commit path does for DEL and DESTROYSET commands.
In both cases all remaining elements will be released via
set->ops->destroy().
The existing abort code does NOT post the actual release to the work queue.
Also the entire __nf_tables_abort() function is wrapped in gc_seq
begin/end pair.
Therefore, async gc worker will never try to release the pending set
elements, as gc sequence is always stale.
It might be possible to speed up transaction aborts via work queue too,
this would result in a race and a possible use-after-free.
So fix this before it becomes an issue.
Fixes: 5f68718b34 ("netfilter: nf_tables: GC transaction API to avoid race with control plane")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3f0465a9ef ("netfilter: nf_tables: dynamically allocate hooks per
net_device in flowtables") reworks flowtable support to allow for
dynamic allocation of hooks, which implicitly fixes the following
bogus EBUSY in transaction:
delete flowtable
add flowtable # same flowtable with same devices, it hits EBUSY
This patch does not exist in any tree, but it fixes this issue for
-stable Linux kernel 4.19
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit c9bd26513b upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 179d9ba555 upstream.
The dormant flag need to be updated from the preparation phase,
otherwise, two consecutive requests to dorm a table in the same batch
might try to remove the same hooks twice, resulting in the following
warning:
hook not found, pf 3 num 0
WARNING: CPU: 0 PID: 334 at net/netfilter/core.c:480 __nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480
Modules linked in:
CPU: 0 PID: 334 Comm: kworker/u4:5 Not tainted 5.12.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: netns cleanup_net
RIP: 0010:__nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480
This patch is a partial revert of 0ce7cf4127 ("netfilter: nftables:
update table flags from the commit phase") to restore the previous
behaviour.
However, there is still another problem: A batch containing a series of
dorm-wakeup-dorm table and vice-versa also trigger the warning above
since hook unregistration happens from the preparation phase, while hook
registration occurs from the commit phase.
To fix this problem, this patch adds two internal flags to annotate the
original dormant flag status which are __NFT_TABLE_F_WAS_DORMANT and
__NFT_TABLE_F_WAS_AWAKEN, to restore it from the abort path.
The __NFT_TABLE_F_UPDATE bitmask allows to handle the dormant flag update
with one single transaction.
Reported-by: syzbot+7ad5cd1615f2d89c6e7e@syzkaller.appspotmail.com
Fixes: 0ce7cf4127 ("netfilter: nftables: update table flags from the commit phase")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0ce7cf4127 upstream.
Do not update table flags from the preparation phase. Store the flags
update into the transaction, then update the flags from the commit
phase.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f9a43007d3 upstream.
__nft_release_hooks() is called from pre_netns exit path which
unregisters the hooks, then the NETDEV_UNREGISTER event is triggered
which unregisters the hooks again.
[ 565.221461] WARNING: CPU: 18 PID: 193 at net/netfilter/core.c:495 __nf_unregister_net_hook+0x247/0x270
[...]
[ 565.246890] CPU: 18 PID: 193 Comm: kworker/u64:1 Tainted: G E 5.18.0-rc7+ #27
[ 565.253682] Workqueue: netns cleanup_net
[ 565.257059] RIP: 0010:__nf_unregister_net_hook+0x247/0x270
[...]
[ 565.297120] Call Trace:
[ 565.300900] <TASK>
[ 565.304683] nf_tables_flowtable_event+0x16a/0x220 [nf_tables]
[ 565.308518] raw_notifier_call_chain+0x63/0x80
[ 565.312386] unregister_netdevice_many+0x54f/0xb50
Unregister and destroy netdev hook from netns pre_exit via kfree_rcu
so the NETDEV_UNREGISTER path see unregistered hooks.
Fixes: 767d1216bf ("netfilter: nftables: fix possible UAF over chains from packet path in netns")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6069da443b upstream.
Unregister flowtable hooks before they are releases via
nf_tables_flowtable_destroy() otherwise hook core reports UAF.
BUG: KASAN: use-after-free in nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142
Read of size 4 at addr ffff8880736f7438 by task syz-executor579/3666
CPU: 0 PID: 3666 Comm: syz-executor579 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
__dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106
dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106
print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
__kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450
kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450
nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142
__nf_register_net_hook+0x27e/0x8d0 net/netfilter/core.c:429 net/netfilter/core.c:429
nf_register_net_hook+0xaa/0x180 net/netfilter/core.c:571 net/netfilter/core.c:571
nft_register_flowtable_net_hooks+0x3c5/0x730 net/netfilter/nf_tables_api.c:7232 net/netfilter/nf_tables_api.c:7232
nf_tables_newflowtable+0x2022/0x2cf0 net/netfilter/nf_tables_api.c:7430 net/netfilter/nf_tables_api.c:7430
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline]
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] net/netfilter/nfnetlink.c:652
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] net/netfilter/nfnetlink.c:652
nfnetlink_rcv+0x10e6/0x2550 net/netfilter/nfnetlink.c:652 net/netfilter/nfnetlink.c:652
__nft_release_hook() calls nft_unregister_flowtable_net_hooks() which
only unregisters the hooks, then after RCU grace period, it is
guaranteed that no packets add new entries to the flowtable (no flow
offload rules and flowtable hooks are reachable from packet path), so it
is safe to call nf_flow_table_free() which cleans up the remaining
entries from the flowtable (both software and hardware) and it unbinds
the flow_block.
Fixes: ff4bf2f42a ("netfilter: nf_tables: add nft_unregister_flowtable_hook()")
Reported-by: syzbot+e918523f77e62790d6d9@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cf5000a778 upstream.
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>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 720344340f upstream.
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 02c6c24402 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6a33d8b73d upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit a2dd0233cb upstream.
Ditch it, it has been replace it by the GC transaction API and it has no
clients anymore.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5f68718b34 upstream.
[ this includes
8357bc946a ("netfilter: nf_tables: use correct lock to protect gc_list") ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 24138933b9 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 628bd3e49c ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f8bb7889af upstream.
Rename:
- nft_set_elem_activate() to nft_set_elem_data_activate().
- nft_set_elem_deactivate() to nft_set_elem_data_deactivate().
To prepare for updates in the set element infrastructure to add support
for the special catch-all element.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0c2a85edd1 upstream.
The patch that adds support for stateful expressions in set definitions
require this.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f969eb84ce ]
nft_unregister_expr() can concurrent with __nft_expr_type_get(),
and there is not any protection when iterate over nf_tables_expressions
list in __nft_expr_type_get(). Therefore, there is potential data-race
of nf_tables_expressions list entry.
Use list_for_each_entry_rcu() to iterate over nf_tables_expressions
list in __nft_expr_type_get(), and use rcu_read_lock() in the caller
nft_expr_type_get() to protect the entire type query process.
Fixes: ef1f7df917 ("netfilter: nf_tables: expression ops overloading")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9cff126f73 ]
In case that there are two types, prefer the family specify extension.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Stable-dep-of: f969eb84ce ("netfilter: nf_tables: Fix potential data-race in __nft_expr_type_get()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 24225011d8 upstream.
nft_unregister_flowtable_type() within nf_flow_inet_module_exit() can
concurrent with __nft_flowtable_type_get() within nf_tables_newflowtable().
And thhere is not any protection when iterate over nf_tables_flowtables
list in __nft_flowtable_type_get(). Therefore, there is pertential
data-race of nf_tables_flowtables list entry.
Use list_for_each_entry_rcu() to iterate over nf_tables_flowtables list
in __nft_flowtable_type_get(), and use rcu_read_lock() in the caller
nft_flowtable_type_get() to protect the entire type query process.
Fixes: 3b49e2e94e ("netfilter: nf_tables: add flow table netlink frontend")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e26d3009ef upstream.
Never used from userspace, disallow these parameters.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[Keerthana: code surrounding the patch is different
because nft_set_desc is not present in v4.19-v5.10]
Signed-off-by: Keerthana K <keerthana.kalyanasundaram@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5f4fc4bd5c upstream.
This set combination is weird: it allows for elements to be
added/deleted, but once bound to the rule it cannot be updated anymore.
Eventually, all elements expire, leading to an empty set which cannot
be updated anymore. Reject this flags combination.
Cc: stable@vger.kernel.org
Fixes: 761da2935d ("netfilter: nf_tables: add set timeout API support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 16603605b6 upstream.
Anonymous sets are never used with timeout from userspace, reject this.
Exception to this rule is NFT_SET_EVAL to ensure legacy meters still work.
Cc: stable@vger.kernel.org
Fixes: 761da2935d ("netfilter: nf_tables: add set timeout API support")
Reported-by: lonial con <kongln9170@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f342de4e2f upstream.
This reverts commit e0abdadcc6.
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: e0abdadcc6 ("netfilter: nf_tables: accept QUEUE/DROP verdict parameters")
Cc: stable@vger.kernel.org
Reported-by: Notselwyn <notselwyn@pwning.tech>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b462579b2b ]
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: 387454901b ("netfilter: nf_tables: Allow set names of up to 255 chars")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit f1082dd31f upstream.
An nftables family is merely a hollow container, its family just a
number and such not reliant on compile-time options other than nftables
support itself. Add an artificial check so attempts at using a family
the kernel can't support fail as early as possible. This helps user
space detect kernels which lack e.g. NFPROTO_INET.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 23a3bfd4ba ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 26b5a5712e upstream.
Missing NFT_TRANS_PREPARE_ERROR in 1df28fde12 ("netfilter: nf_tables: add
NFT_TRANS_PREPARE_ERROR to deal with bound set/chain") in 4.19.
Fixes: 1df28fde12 ("netfilter: nf_tables: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain") in 4.19
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1689f25924 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Laura Garcia Liebana <nevola@gmail.com>
commit 9b05b6e11d upstream.
The deletion of a flowtable after a flush in the same transaction
results in EBUSY. This patch adds an activation and deactivation of
flowtables in order to update the _use_ counter.
Signed-off-by: Laura Garcia Liebana <nevola@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 314c828416 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ddbd8be689 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ 2024439bd5 ]
nf_tables_check_loops() can be called from rhashtable list
walk so cond_resched() cannot be used here.
Fixes: 81ea010667 ("netfilter: nf_tables: add rescheduling points during loop detection walks")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 3e70489721 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 938154b93b ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 26b5a5712e ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 1240eb93f0 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 0854db2aae ]
This moves all nf_tables pernet data from struct net to a net_generic
extension, with the exception of the gencursor.
The latter is used in the data path and also outside of the nf_tables
core. All others are only used from the configuration plane.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 19c28b1374 ]
This patch adds a helper function to set up the netlink and nfnetlink headers.
Update existing codebase to use it.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 802b805162 ]
This patch adds a helper function to calculate the base sequence number
field that is stored in the nfnetlink header. Use the helper function
whenever possible.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 81ea010667 ]
Add explicit rescheduling points during ruleset walk.
Switching to a faster algorithm is possible but this is a much
smaller change, suitable for nf tree.
Link: https://bugzilla.netfilter.org/show_bug.cgi?id=1460
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ 1e9451cbda ]
sybot came up with following transaction:
add table ip syz0
add chain ip syz0 syz2 { type nat hook prerouting priority 0; policy accept; }
add table ip syz0 { flags dormant; }
delete chain ip syz0 syz2
delete table ip syz0
which yields:
hook not found, pf 2 num 0
WARNING: CPU: 0 PID: 6775 at net/netfilter/core.c:413 __nf_unregister_net_hook+0x3e6/0x4a0 net/netfilter/core.c:413
[..]
nft_unregister_basechain_hooks net/netfilter/nf_tables_api.c:206 [inline]
nft_table_disable net/netfilter/nf_tables_api.c:835 [inline]
nf_tables_table_disable net/netfilter/nf_tables_api.c:868 [inline]
nf_tables_commit+0x32d3/0x4d70 net/netfilter/nf_tables_api.c:7550
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:486 [inline]
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:544 [inline]
nfnetlink_rcv+0x14a5/0x1e50 net/netfilter/nfnetlink.c:562
netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
Problem is that when I added ability to override base hook registration
to make nat basechains register with the nat core instead of netfilter
core, I forgot to update nft_table_disable() to use that instead of
the 'raw' hook register interface.
In syzbot transaction, the basechain is of 'nat' type. Its registered
with the nat core. The switch to 'dormant mode' attempts to delete from
netfilter core instead.
After updating nft_table_disable/enable to use the correct helper,
nft_(un)register_basechain_hooks can be folded into the only remaining
caller.
Because nft_trans_table_enable() won't do anything when the DORMANT flag
is set, remove the flag first, then re-add it in case re-enablement
fails, else this patch breaks sequence:
add table ip x { flags dormant; }
/* add base chains */
add table ip x
The last 'add' will remove the dormant flags, but won't have any other
effect -- base chains are not registered.
Then, next 'set dormant flag' will create another 'hook not found'
splat.
Reported-by: syzbot+2570f2c036e3da5db176@syzkaller.appspotmail.com
Fixes: 4e25ceb80b ("netfilter: nf_tables: allow chain type to override hook register")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
(cherry picked from commit 1e9451cbda)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c88c535b59 ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Pablo Neira Ayuso