linux-stable.git/include/net/netfilter, branch linux-7.0.y Linux kernel stable tree netfilter: nfnetlink_queue: make hash table per queue 2026-04-08T11:34:51+00:00 Florian Westphal fw@strlen.de 2026-04-07T15:00:01+00:00 936206e3f6ff411581e615e930263d6f8b78df9d Sharing a global hash table among all queues is tempting, but it can cause crash: BUG: KASAN: slab-use-after-free in nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] [..] nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] nfnetlink_rcv_msg+0x46a/0x930 kmem_cache_alloc_node_noprof+0x11e/0x450 struct nf_queue_entry is freed via kfree, but parallel cpu can still encounter such an nf_queue_entry when walking the list. Alternative fix is to free the nf_queue_entry via kfree_rcu() instead, but as we have to alloc/free for each skb this will cause more mem pressure. Cc: Scott Mitchell <scott.k.mitch1@gmail.com> Fixes: e19079adcd26 ("netfilter: nfnetlink_queue: optimize verdict lookup with hash table") Signed-off-by: Florian Westphal <fw@strlen.de> 
Sharing a global hash table among all queues is tempting, but
it can cause crash:

BUG: KASAN: slab-use-after-free in nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue]
[..]
 nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue]
 nfnetlink_rcv_msg+0x46a/0x930
 kmem_cache_alloc_node_noprof+0x11e/0x450

struct nf_queue_entry is freed via kfree, but parallel cpu can still
encounter such an nf_queue_entry when walking the list.

Alternative fix is to free the nf_queue_entry via kfree_rcu() instead,
but as we have to alloc/free for each skb this will cause more mem
pressure.

Cc: Scott Mitchell <scott.k.mitch1@gmail.com>
Fixes: e19079adcd26 ("netfilter: nfnetlink_queue: optimize verdict lookup with hash table")
Signed-off-by: Florian Westphal <fw@strlen.de>
netfilter: nft_ct: fix use-after-free in timeout object destroy 2026-04-08T11:34:16+00:00 Tuan Do tuan@calif.io 2026-04-03T07:33:17+00:00 f8dca15a1b190787bbd03285304b569631160eda nft_ct_timeout_obj_destroy() frees the timeout object with kfree() immediately after nf_ct_untimeout(), without waiting for an RCU grace period. Concurrent packet processing on other CPUs may still hold RCU-protected references to the timeout object obtained via rcu_dereference() in nf_ct_timeout_data(). Add an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer freeing until after an RCU grace period, matching the approach already used in nfnetlink_cttimeout.c. KASAN report: BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0 Read of size 4 at addr ffff8881035fe19c by task exploit/80 Call Trace: nf_conntrack_tcp_packet+0x1381/0x29d0 nf_conntrack_in+0x612/0x8b0 nf_hook_slow+0x70/0x100 __ip_local_out+0x1b2/0x210 tcp_sendmsg_locked+0x722/0x1580 __sys_sendto+0x2d8/0x320 Allocated by task 75: nft_ct_timeout_obj_init+0xf6/0x290 nft_obj_init+0x107/0x1b0 nf_tables_newobj+0x680/0x9c0 nfnetlink_rcv_batch+0xc29/0xe00 Freed by task 26: nft_obj_destroy+0x3f/0xa0 nf_tables_trans_destroy_work+0x51c/0x5c0 process_one_work+0x2c4/0x5a0 Fixes: 7e0b2b57f01d ("netfilter: nft_ct: add ct timeout support") Cc: stable@vger.kernel.org Signed-off-by: Tuan Do <tuan@calif.io> Signed-off-by: Florian Westphal <fw@strlen.de> 
nft_ct_timeout_obj_destroy() frees the timeout object with kfree()
immediately after nf_ct_untimeout(), without waiting for an RCU grace
period. Concurrent packet processing on other CPUs may still hold
RCU-protected references to the timeout object obtained via
rcu_dereference() in nf_ct_timeout_data().

Add an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer
freeing until after an RCU grace period, matching the approach already
used in nfnetlink_cttimeout.c.

KASAN report:
 BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0
 Read of size 4 at addr ffff8881035fe19c by task exploit/80

 Call Trace:
  nf_conntrack_tcp_packet+0x1381/0x29d0
  nf_conntrack_in+0x612/0x8b0
  nf_hook_slow+0x70/0x100
  __ip_local_out+0x1b2/0x210
  tcp_sendmsg_locked+0x722/0x1580
  __sys_sendto+0x2d8/0x320

 Allocated by task 75:
  nft_ct_timeout_obj_init+0xf6/0x290
  nft_obj_init+0x107/0x1b0
  nf_tables_newobj+0x680/0x9c0
  nfnetlink_rcv_batch+0xc29/0xe00

 Freed by task 26:
  nft_obj_destroy+0x3f/0xa0
  nf_tables_trans_destroy_work+0x51c/0x5c0
  process_one_work+0x2c4/0x5a0

Fixes: 7e0b2b57f01d ("netfilter: nft_ct: add ct timeout support")
Cc: stable@vger.kernel.org
Signed-off-by: Tuan Do <tuan@calif.io>
Signed-off-by: Florian Westphal <fw@strlen.de>
netfilter: nf_conntrack_expect: store netns and zone in expectation 2026-03-26T12:24:40+00:00 Pablo Neira Ayuso pablo@netfilter.org 2026-03-25T21:39:55+00:00 02a3231b6d82efe750da6554ebf280e4a6f78756 __nf_ct_expect_find() and nf_ct_expect_find_get() are called under rcu_read_lock() but they dereference the master conntrack via exp->master. Since the expectation does not hold a reference on the master conntrack, this could be dying conntrack or different recycled conntrack than the real master due to SLAB_TYPESAFE_RCU. Store the netns, the master_tuple and the zone in struct nf_conntrack_expect as a safety measure. This patch is required by the follow up fix not to dump expectations that do not belong to this netns. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> 
__nf_ct_expect_find() and nf_ct_expect_find_get() are called under
rcu_read_lock() but they dereference the master conntrack via
exp->master.

Since the expectation does not hold a reference on the master conntrack,
this could be dying conntrack or different recycled conntrack than the
real master due to SLAB_TYPESAFE_RCU.

Store the netns, the master_tuple and the zone in struct
nf_conntrack_expect as a safety measure.

This patch is required by the follow up fix not to dump expectations
that do not belong to this netns.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: ctnetlink: ensure safe access to master conntrack 2026-03-26T12:18:32+00:00 Pablo Neira Ayuso pablo@netfilter.org 2026-03-25T13:11:04+00:00 bffcaad9afdfe45d7fc777397d3b83c1e3ebffe5 Holding reference on the expectation is not sufficient, the master conntrack object can just go away, making exp->master invalid. To access exp->master safely: - Grab the nf_conntrack_expect_lock, this gets serialized with clean_from_lists() which also holds this lock when the master conntrack goes away. - Hold reference on master conntrack via nf_conntrack_find_get(). Not so easy since the master tuple to look up for the master conntrack is not available in the existing problematic paths. This patch goes for extending the nf_conntrack_expect_lock section to address this issue for simplicity, in the cases that are described below this is just slightly extending the lock section. The add expectation command already holds a reference to the master conntrack from ctnetlink_create_expect(). However, the delete expectation command needs to grab the spinlock before looking up for the expectation. Expand the existing spinlock section to address this to cover the expectation lookup. Note that, the nf_ct_expect_iterate_net() calls already grabs the spinlock while iterating over the expectation table, which is correct. The get expectation command needs to grab the spinlock to ensure master conntrack does not go away. This also expands the existing spinlock section to cover the expectation lookup too. I needed to move the netlink skb allocation out of the spinlock to keep it GFP_KERNEL. For the expectation events, the IPEXP_DESTROY event is already delivered under the spinlock, just move the delivery of IPEXP_NEW under the spinlock too because the master conntrack event cache is reached through exp->master. While at it, add lockdep notations to help identify what codepaths need to grab the spinlock. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> 
Holding reference on the expectation is not sufficient, the master
conntrack object can just go away, making exp->master invalid.

To access exp->master safely:

- Grab the nf_conntrack_expect_lock, this gets serialized with
  clean_from_lists() which also holds this lock when the master
  conntrack goes away.

- Hold reference on master conntrack via nf_conntrack_find_get().
  Not so easy since the master tuple to look up for the master conntrack
  is not available in the existing problematic paths.

This patch goes for extending the nf_conntrack_expect_lock section
to address this issue for simplicity, in the cases that are described
below this is just slightly extending the lock section.

The add expectation command already holds a reference to the master
conntrack from ctnetlink_create_expect().

However, the delete expectation command needs to grab the spinlock
before looking up for the expectation. Expand the existing spinlock
section to address this to cover the expectation lookup. Note that,
the nf_ct_expect_iterate_net() calls already grabs the spinlock while
iterating over the expectation table, which is correct.

The get expectation command needs to grab the spinlock to ensure master
conntrack does not go away. This also expands the existing spinlock
section to cover the expectation lookup too. I needed to move the
netlink skb allocation out of the spinlock to keep it GFP_KERNEL.

For the expectation events, the IPEXP_DESTROY event is already delivered
under the spinlock, just move the delivery of IPEXP_NEW under the
spinlock too because the master conntrack event cache is reached through
exp->master.

While at it, add lockdep notations to help identify what codepaths need
to grab the spinlock.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
netfilter: nf_conntrack_expect: honor expectation helper field 2026-03-26T12:18:31+00:00 Pablo Neira Ayuso pablo@netfilter.org 2026-03-25T13:11:02+00:00 9c42bc9db90a154bc61ae337a070465f3393485a The expectation helper field is mostly unused. As a result, the netfilter codebase relies on accessing the helper through exp->master. Always set on the expectation helper field so it can be used to reach the helper. nf_ct_expect_init() is called from packet path where the skb owns the ct object, therefore accessing exp->master for the newly created expectation is safe. This saves a lot of updates in all callsites to pass the ct object as parameter to nf_ct_expect_init(). This is a preparation patches for follow up fixes. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> 
The expectation helper field is mostly unused. As a result, the
netfilter codebase relies on accessing the helper through exp->master.

Always set on the expectation helper field so it can be used to reach
the helper.

nf_ct_expect_init() is called from packet path where the skb owns
the ct object, therefore accessing exp->master for the newly created
expectation is safe. This saves a lot of updates in all callsites
to pass the ct object as parameter to nf_ct_expect_init().

This is a preparation patches for follow up fixes.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_tables: nft_dynset: fix possible stateful expression memleak in error path 2026-03-13T14:31:15+00:00 Pablo Neira Ayuso pablo@netfilter.org 2026-03-12T11:38:59+00:00 0548a13b5a145b16e4da0628b5936baf35f51b43 If cloning the second stateful expression in the element via GFP_ATOMIC fails, then the first stateful expression remains in place without being released.   unreferenced object (percpu) 0x607b97e9cab8 (size 16):     comm "softirq", pid 0, jiffies 4294931867     hex dump (first 16 bytes on cpu 3):       00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00     backtrace (crc 0):       pcpu_alloc_noprof+0x453/0xd80       nft_counter_clone+0x9c/0x190 [nf_tables]       nft_expr_clone+0x8f/0x1b0 [nf_tables]       nft_dynset_new+0x2cb/0x5f0 [nf_tables]       nft_rhash_update+0x236/0x11c0 [nf_tables]       nft_dynset_eval+0x11f/0x670 [nf_tables]       nft_do_chain+0x253/0x1700 [nf_tables]       nft_do_chain_ipv4+0x18d/0x270 [nf_tables]       nf_hook_slow+0xaa/0x1e0       ip_local_deliver+0x209/0x330 Fixes: 563125a73ac3 ("netfilter: nftables: generalize set extension to support for several expressions") Reported-by: Gurpreet Shergill <giki.shergill@proton.me> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de> 
If cloning the second stateful expression in the element via GFP_ATOMIC
fails, then the first stateful expression remains in place without being
released.

   unreferenced object (percpu) 0x607b97e9cab8 (size 16):
     comm "softirq", pid 0, jiffies 4294931867
     hex dump (first 16 bytes on cpu 3):
       00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
     backtrace (crc 0):
       pcpu_alloc_noprof+0x453/0xd80
       nft_counter_clone+0x9c/0x190 [nf_tables]
       nft_expr_clone+0x8f/0x1b0 [nf_tables]
       nft_dynset_new+0x2cb/0x5f0 [nf_tables]
       nft_rhash_update+0x236/0x11c0 [nf_tables]
       nft_dynset_eval+0x11f/0x670 [nf_tables]
       nft_do_chain+0x253/0x1700 [nf_tables]
       nft_do_chain_ipv4+0x18d/0x270 [nf_tables]
       nf_hook_slow+0xaa/0x1e0
       ip_local_deliver+0x209/0x330

Fixes: 563125a73ac3 ("netfilter: nftables: generalize set extension to support for several expressions")
Reported-by: Gurpreet Shergill <giki.shergill@proton.me>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
netfilter: revert nft_set_rbtree: validate open interval overlap 2026-03-13T14:31:14+00:00 Florian Westphal fw@strlen.de 2026-03-11T15:24:02+00:00 598adea720b97572c7028635cb1c59b3684e128c This reverts commit 648946966a08 ("netfilter: nft_set_rbtree: validate open interval overlap"). There have been reports of nft failing to laod valid rulesets after this patch was merged into -stable. I can reproduce several such problem with recent nft versions, including nft 1.1.6 which is widely shipped by distributions. We currently have little choice here. This commit can be resurrected at some point once the nftables fix that triggers the false overlap positive has appeared in common distros (see e83e32c8d1cd ("mnl: restore create element command with large batches" in nftables.git). Fixes: 648946966a08 ("netfilter: nft_set_rbtree: validate open interval overlap") Acked-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de> 
This reverts commit 648946966a08 ("netfilter: nft_set_rbtree: validate
open interval overlap").

There have been reports of nft failing to laod valid rulesets after this
patch was merged into -stable.

I can reproduce several such problem with recent nft versions, including
nft 1.1.6 which is widely shipped by distributions.

We currently have little choice here.
This commit can be resurrected at some point once the nftables fix that
triggers the false overlap positive has appeared in common distros
(see e83e32c8d1cd ("mnl: restore create element command with large batches" in
 nftables.git).

Fixes: 648946966a08 ("netfilter: nft_set_rbtree: validate open interval overlap")
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
netfilter: nft_set_pipapo: split gc into unlink and reclaim phase 2026-03-05T12:22:37+00:00 Florian Westphal fw@strlen.de 2026-03-03T15:31:32+00:00 9df95785d3d8302f7c066050117b04cd3c2048c2 Yiming Qian reports Use-after-free in the pipapo set type: Under a large number of expired elements, commit-time GC can run for a very long time in a non-preemptible context, triggering soft lockup warnings and RCU stall reports (local denial of service). We must split GC in an unlink and a reclaim phase. We cannot queue elements for freeing until pointers have been swapped. Expired elements are still exposed to both the packet path and userspace dumpers via the live copy of the data structure. call_rcu() does not protect us: dump operations or element lookups starting after call_rcu has fired can still observe the free'd element, unless the commit phase has made enough progress to swap the clone and live pointers before any new reader has picked up the old version. This a similar approach as done recently for the rbtree backend in commit 35f83a75529a ("netfilter: nft_set_rbtree: don't gc elements on insert"). Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges") Reported-by: Yiming Qian <yimingqian591@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> 
Yiming Qian reports Use-after-free in the pipapo set type:
  Under a large number of expired elements, commit-time GC can run for a very
  long time in a non-preemptible context, triggering soft lockup warnings and
  RCU stall reports (local denial of service).

We must split GC in an unlink and a reclaim phase.

We cannot queue elements for freeing until pointers have been swapped.
Expired elements are still exposed to both the packet path and userspace
dumpers via the live copy of the data structure.

call_rcu() does not protect us: dump operations or element lookups starting
after call_rcu has fired can still observe the free'd element, unless the
commit phase has made enough progress to swap the clone and live pointers
before any new reader has picked up the old version.

This a similar approach as done recently for the rbtree backend in commit
35f83a75529a ("netfilter: nft_set_rbtree: don't gc elements on insert").

Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
netfilter: nf_tables: clone set on flush only 2026-03-05T12:22:37+00:00 Pablo Neira Ayuso pablo@netfilter.org 2026-03-02T22:28:15+00:00 fb7fb4016300ac622c964069e286dc83166a5d52 Syzbot with fault injection triggered a failing memory allocation with GFP_KERNEL which results in a WARN splat: iter.err WARNING: net/netfilter/nf_tables_api.c:845 at nft_map_deactivate+0x34e/0x3c0 net/netfilter/nf_tables_api.c:845, CPU#0: syz.0.17/5992 Modules linked in: CPU: 0 UID: 0 PID: 5992 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:nft_map_deactivate+0x34e/0x3c0 net/netfilter/nf_tables_api.c:845 Code: 8b 05 86 5a 4e 09 48 3b 84 24 a0 00 00 00 75 62 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 63 6d fa f7 90 <0f> 0b 90 43 +80 7c 35 00 00 0f 85 23 fe ff ff e9 26 fe ff ff 89 d9 RSP: 0018:ffffc900045af780 EFLAGS: 00010293 RAX: ffffffff89ca45bd RBX: 00000000fffffff4 RCX: ffff888028111e40 RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000 RBP: ffffc900045af870 R08: 0000000000400dc0 R09: 00000000ffffffff R10: dffffc0000000000 R11: fffffbfff1d141db R12: ffffc900045af7e0 R13: 1ffff920008b5f24 R14: dffffc0000000000 R15: ffffc900045af920 FS: 000055557a6a5500(0000) GS:ffff888125496000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb5ea271fc0 CR3: 000000003269e000 CR4: 00000000003526f0 Call Trace: <TASK> __nft_release_table+0xceb/0x11f0 net/netfilter/nf_tables_api.c:12115 nft_rcv_nl_event+0xc25/0xdb0 net/netfilter/nf_tables_api.c:12187 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380 netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761 __sock_release net/socket.c:662 [inline] sock_close+0xc3/0x240 net/socket.c:1455 Restrict set clone to the flush set command in the preparation phase. Add NFT_ITER_UPDATE_CLONE and use it for this purpose, update the rbtree and pipapo backends to only clone the set when this iteration type is used. As for the existing NFT_ITER_UPDATE type, update the pipapo backend to use the existing set clone if available, otherwise use the existing set representation. After this update, there is no need to clone a set that is being deleted, this includes bound anonymous set. An alternative approach to NFT_ITER_UPDATE_CLONE is to add a .clone interface and call it from the flush set path. Reported-by: syzbot+4924a0edc148e8b4b342@syzkaller.appspotmail.com Fixes: 3f1d886cc7c3 ("netfilter: nft_set_pipapo: move cloning of match info to insert/removal path") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de> 
Syzbot with fault injection triggered a failing memory allocation with
GFP_KERNEL which results in a WARN splat:

iter.err
WARNING: net/netfilter/nf_tables_api.c:845 at nft_map_deactivate+0x34e/0x3c0 net/netfilter/nf_tables_api.c:845, CPU#0: syz.0.17/5992
Modules linked in:
CPU: 0 UID: 0 PID: 5992 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:nft_map_deactivate+0x34e/0x3c0 net/netfilter/nf_tables_api.c:845
Code: 8b 05 86 5a 4e 09 48 3b 84 24 a0 00 00 00 75 62 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 63 6d fa f7 90 <0f> 0b 90 43
+80 7c 35 00 00 0f 85 23 fe ff ff e9 26 fe ff ff 89 d9
RSP: 0018:ffffc900045af780 EFLAGS: 00010293
RAX: ffffffff89ca45bd RBX: 00000000fffffff4 RCX: ffff888028111e40
RDX: 0000000000000000 RSI: 00000000fffffff4 RDI: 0000000000000000
RBP: ffffc900045af870 R08: 0000000000400dc0 R09: 00000000ffffffff
R10: dffffc0000000000 R11: fffffbfff1d141db R12: ffffc900045af7e0
R13: 1ffff920008b5f24 R14: dffffc0000000000 R15: ffffc900045af920
FS:  000055557a6a5500(0000) GS:ffff888125496000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fb5ea271fc0 CR3: 000000003269e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __nft_release_table+0xceb/0x11f0 net/netfilter/nf_tables_api.c:12115
 nft_rcv_nl_event+0xc25/0xdb0 net/netfilter/nf_tables_api.c:12187
 notifier_call_chain+0x19d/0x3a0 kernel/notifier.c:85
 blocking_notifier_call_chain+0x6a/0x90 kernel/notifier.c:380
 netlink_release+0x123b/0x1ad0 net/netlink/af_netlink.c:761
 __sock_release net/socket.c:662 [inline]
 sock_close+0xc3/0x240 net/socket.c:1455

Restrict set clone to the flush set command in the preparation phase.
Add NFT_ITER_UPDATE_CLONE and use it for this purpose, update the rbtree
and pipapo backends to only clone the set when this iteration type is
used.

As for the existing NFT_ITER_UPDATE type, update the pipapo backend to
use the existing set clone if available, otherwise use the existing set
representation. After this update, there is no need to clone a set that
is being deleted, this includes bound anonymous set.

An alternative approach to NFT_ITER_UPDATE_CLONE is to add a .clone
interface and call it from the flush set path.

Reported-by: syzbot+4924a0edc148e8b4b342@syzkaller.appspotmail.com
Fixes: 3f1d886cc7c3 ("netfilter: nft_set_pipapo: move cloning of match info to insert/removal path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Merge tag 'nf-next-26-02-06' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next 2026-02-11T04:25:38+00:00 Jakub Kicinski kuba@kernel.org 2026-02-11T04:25:38+00:00 792aaea994537daa78f31a86c948ccbefa8f4706 Florian Westphal says: ==================== netfilter: updates for net-next The following patchset contains Netfilter updates for *net-next*: 1) Fix net-next-only use-after-free bug in nf_tables rbtree set: Expired elements cannot be released right away after unlink anymore because there is no guarantee that the binary-search blob is going to be updated. Spotted by syzkaller. 2) Fix esoteric bug in nf_queue with udp fraglist gro, broken since 6.11. Patch 3 adds extends the nfqueue selftest for this. 4) Use dedicated slab for flowtable entries, currently the -512 cache is used, which is wasteful. From Qingfang Deng. 5) Recent net-next update extended existing test for ip6ip6 tunnels, add the required /config entry. Test still passed by accident because the previous tests network setup gets re-used, so also update the test so it will fail in case the ip6ip6 tunnel interface cannot be added. 6) Fix 'nft get element mytable myset { 1.2.3.4 }' on big endian platforms, this was broken since code was added in v5.1. 7) Fix nf_tables counter reset support on 32bit platforms, where counter reset may cause huge values to appear due to wraparound. Broken since reset feature was added in v6.11. From Anders Grahn. 8-11) update nf_tables rbtree set type to detect partial operlaps. This will eventually speed up nftables userspace: at this time userspace does a netlink dump of the set content which slows down incremental updates on interval sets. From Pablo Neira Ayuso. * tag 'nf-next-26-02-06' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next: netfilter: nft_set_rbtree: validate open interval overlap netfilter: nft_set_rbtree: validate element belonging to interval netfilter: nft_set_rbtree: check for partial overlaps in anonymous sets netfilter: nft_set_rbtree: fix bogus EEXIST with NLM_F_CREATE with null interval netfilter: nft_counter: fix reset of counters on 32bit archs netfilter: nft_set_hash: fix get operation on big endian selftests: netfilter: add IPV6_TUNNEL to config netfilter: flowtable: dedicated slab for flow entry selftests: netfilter: nft_queue.sh: add udp fraglist gro test case netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation netfilter: nft_set_rbtree: don't gc elements on insert ==================== Link: https://patch.msgid.link/20260206153048.17570-1-fw@strlen.de Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Florian Westphal says:

====================
netfilter: updates for net-next

The following patchset contains Netfilter updates for *net-next*:

1) Fix net-next-only use-after-free bug in nf_tables rbtree set:
   Expired elements cannot be released right away after unlink anymore
   because there is no guarantee that the binary-search blob is going to
   be updated.  Spotted by syzkaller.

2) Fix esoteric bug in nf_queue with udp fraglist gro, broken since
   6.11. Patch 3 adds extends the nfqueue selftest for this.

4) Use dedicated slab for flowtable entries, currently the -512 cache
   is used, which is wasteful.  From Qingfang Deng.

5) Recent net-next update extended existing test for ip6ip6 tunnels, add
   the required /config entry.  Test still passed by accident because the
   previous tests network setup gets re-used, so also update the test so
   it will fail in case the ip6ip6 tunnel interface cannot be added.

6) Fix 'nft get element mytable myset { 1.2.3.4 }' on big endian
   platforms, this was broken since code was added in v5.1.

7) Fix nf_tables counter reset support on 32bit platforms, where counter
   reset may cause huge values to appear due to wraparound.
   Broken since reset feature was added in v6.11.  From Anders Grahn.

8-11) update nf_tables rbtree set type to detect partial
   operlaps.  This will eventually speed up nftables userspace: at this
   time userspace does a netlink dump of the set content which slows down
   incremental updates on interval sets.  From Pablo Neira Ayuso.

* tag 'nf-next-26-02-06' of https://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
  netfilter: nft_set_rbtree: validate open interval overlap
  netfilter: nft_set_rbtree: validate element belonging to interval
  netfilter: nft_set_rbtree: check for partial overlaps in anonymous sets
  netfilter: nft_set_rbtree: fix bogus EEXIST with NLM_F_CREATE with null interval
  netfilter: nft_counter: fix reset of counters on 32bit archs
  netfilter: nft_set_hash: fix get operation on big endian
  selftests: netfilter: add IPV6_TUNNEL to config
  netfilter: flowtable: dedicated slab for flow entry
  selftests: netfilter: nft_queue.sh: add udp fraglist gro test case
  netfilter: nfnetlink_queue: do shared-unconfirmed check before segmentation
  netfilter: nft_set_rbtree: don't gc elements on insert
====================

Link: https://patch.msgid.link/20260206153048.17570-1-fw@strlen.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>