FAILED: patch "[PATCH] netfilter: nf_tables: skip expired catchall elements on" failed to apply to 5.15-stable tree

PATCH New [email protected] 2 participants 3 messages Sep 29 – Sep 30

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Networking Stable branch netfilter

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[email protected]

author maintainer

2026-09-29 09:39 UTC #0 lore raw

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x 70194dc37670bd08e44b471389861cc01bd3a3c9
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026092923-masses-playroom-aefc@gregkh' --subject-prefix 'PATCH 5.15.y' 'HEAD^..'

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 70194dc37670bd08e44b471389861cc01bd3a3c9 Mon Sep 17 00:00:00 2001
From: Aohan Mei <[email protected]>
Date: Mon, 14 Sep 2026 19:51:47 +0800
Subject: [PATCH] netfilter: nf_tables: skip expired catchall elements on
insert and delete

nft_setelem_catchall_insert() looks up duplicates with nft_set_elem_active() only, while nft_set_catchall_lookup() and the dump path additionally skip expired elements.

Once a catchall element with a timeout expires, this predicate drift makes it invisible to userspace dumps, yet it still blocks
re-insertion: with NLM_F_EXCL the request fails with -EEXIST, and without it the request reports success but silently inserts nothing. The stale entry only goes away when the (user-tunable) gc interval elapses, so the catchall rule may silently stop matching for an arbitrarily long time after its first expiration.

The delete path shows the same drift: nft_setelem_catchall_deactivate() picks the first active-next entry in the catchall list, so with an expired entry still pending GC it retires the stale entry instead of the fresh one, and it deactivates an element that userspace no longer sees instead of failing with -ENOENT.

Align both walks with the lookup and dump predicates: only an element that is active and not expired counts as a duplicate or delete candidate, using the per-netns timestamp taken at transaction start, in line with the set backend .insert/.deactivate and catchall GC sync paths.

Reported-by TencentOS Corvus AI <[email protected]>

Cc [email protected]

Fixes aaa31047a6d2 ("netfilter: nftables: add catch-all set element support")

Assisted-by CodeBuddy:Kimi-K3

Signed-off-by Aohan Mei <[email protected]>

Signed-off-by Pablo Neira Ayuso <[email protected]>

net/netfilter/nf_tables_api.c +8 -2

index c0b754a2d45b..b59628e6240c 100644
@@ -6995,11 +6995,14 @@ static int nft_setelem_catchall_insert(const struct net *net,
 {
 	struct nft_set_elem_catchall *catchall;
 	u8 genmask = nft_genmask_next(net);
+	u64 tstamp = nft_net_tstamp(net);
 	struct nft_set_ext *ext;
 
 	list_for_each_entry(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
-		if (nft_set_elem_active(ext, genmask)) {
+		if (nft_set_elem_active(ext, genmask) &&
+		    !__nft_set_elem_expired(ext, tstamp) &&
+		    !nft_set_elem_is_dead(ext)) {
 			*priv = catchall->elem;
 			return -EEXIST;
 		}

@@ -7092,11 +7095,14 @@ static int nft_setelem_catchall_deactivate(const struct net *net,
 					   struct nft_set_elem *elem)
 {
 	struct nft_set_elem_catchall *catchall;
+	u64 tstamp = nft_net_tstamp(net);
 	struct nft_set_ext *ext;
 
 	list_for_each_entry(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
-		if (!nft_is_active_next(net, ext))
+		if (!nft_is_active_next(net, ext) ||
+		    __nft_set_elem_expired(ext, tstamp) ||
+		    nft_set_elem_is_dead(ext))
 			continue;
 
 		kfree(elem->priv);

Sasha Levin

maintainer

2026-09-30 15:44 UTC #1 lore raw

PATCH 1/2 netfilter: nf_tables: set->ops->insert returns opaque set element in case of EEXIST

From: Pablo Neira Ayuso <[email protected]>

[ Upstream commit 078996fcd657e6e0c3a72b7d5806d04c32e74250 ]

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 <[email protected]>

Backport adaptation for Linux 5.15:
This tree represents opaque set elements as void pointers and does not have struct nft_elem_priv, the backend priv members, or nft_elem_priv_cast(). Use void ** for the insert output parameter and return the existing backend element pointer directly. Keep the frontend conversion through nft_set_elem_ext() when insertion returns -EEXIST.

Resolve the pipapo conflict by retaining its existing initialization of e at declaration and returning e directly. Update the output parameter's documentation and omit the unrelated timeout declaration reordering. No functions or element layout changes are introduced.

This preserves the catchall insertion context needed for target commit 70194dc37670bd08e44b471389861cc01bd3a3c9, whose two hunks apply unchanged.

Stable-dep-of: 70194dc37670 ("netfilter: nf_tables: skip expired catchall elements on insert and delete")

Signed-off-by Sasha Levin <[email protected]>

---
 include/net/netfilter/nf_tables.h |  2 +-
 net/netfilter/nf_tables_api.c     | 15 +++++++++------
 net/netfilter/nft_set_bitmap.c    |  4 ++--
 net/netfilter/nft_set_hash.c      |  8 ++++----
 net/netfilter/nft_set_pipapo.c    | 10 +++++-----
 net/netfilter/nft_set_rbtree.c    | 10 +++++-----
 6 files changed, 26 insertions(+), 23 deletions(-)

include/net/netfilter/nf_tables.h +1 -1

index 2b977d5d6f30f..be271c66329e8 100644
@@ -435,7 +435,7 @@ struct nft_set_ops {
 	int				(*insert)(const struct net *net,
 						  const struct nft_set *set,
 						  const struct nft_set_elem *elem,
-						  struct nft_set_ext **ext);
+						  void **priv);
 	void				(*activate)(const struct net *net,
 						    const struct nft_set *set,
 						    const struct nft_set_elem *elem);

net/netfilter/nf_tables_api.c +9 -6

index c1b5b579ccd72..c1dffddd31be6 100644
@@ -6075,7 +6075,7 @@ EXPORT_SYMBOL_GPL(nft_set_catchall_lookup);
 static int nft_setelem_catchall_insert(const struct net *net,
 				       struct nft_set *set,
 				       const struct nft_set_elem *elem,
-				       struct nft_set_ext **pext)
+				       void **priv)
 {
 	struct nft_set_elem_catchall *catchall;
 	u8 genmask = nft_genmask_next(net);

@@ -6084,7 +6084,7 @@ static int nft_setelem_catchall_insert(const struct net *net,
 	list_for_each_entry(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
 		if (nft_set_elem_active(ext, genmask)) {
-			*pext = ext;
+			*priv = catchall->elem;
 			return -EEXIST;
 		}
 	}

@@ -6102,14 +6102,15 @@ static int nft_setelem_catchall_insert(const struct net *net,
 static int nft_setelem_insert(const struct net *net,
 			      struct nft_set *set,
 			      const struct nft_set_elem *elem,
-			      struct nft_set_ext **ext, unsigned int flags)
+			      void **elem_priv,
+			      unsigned int flags)
 {
 	int ret;
 
 	if (flags & NFT_SET_ELEM_CATCHALL)
-		ret = nft_setelem_catchall_insert(net, set, elem, ext);
+		ret = nft_setelem_catchall_insert(net, set, elem, elem_priv);
 	else
-		ret = set->ops->insert(net, set, elem, ext);
+		ret = set->ops->insert(net, set, elem, elem_priv);
 
 	return ret;
 }

@@ -6255,6 +6256,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 	struct nft_data_desc desc;
 	enum nft_registers dreg;
 	struct nft_trans *trans;
+	void *elem_priv;
 	u64 timeout;
 	u64 expiration;
 	int err, i;

@@ -6549,9 +6551,10 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
 
 	ext->genmask = nft_genmask_cur(ctx->net);
 
-	err = nft_setelem_insert(ctx->net, set, &elem, &ext2, flags);
+	err = nft_setelem_insert(ctx->net, set, &elem, &elem_priv, flags);
 	if (err) {
 		if (err == -EEXIST) {
+			ext2 = nft_set_elem_ext(set, elem_priv);
 			if (nft_set_ext_exists(ext, NFT_SET_EXT_DATA) ^
 			    nft_set_ext_exists(ext2, NFT_SET_EXT_DATA) ||
 			    nft_set_ext_exists(ext, NFT_SET_EXT_OBJREF) ^

net/netfilter/nft_set_bitmap.c +2 -2

index 028955a9cb092..ec12d0f814351 100644
@@ -123,7 +123,7 @@ static void *nft_bitmap_get(const struct net *net, const struct nft_set *set,
 
 static int nft_bitmap_insert(const struct net *net, const struct nft_set *set,
 			     const struct nft_set_elem *elem,
-			     struct nft_set_ext **ext)
+			     void **elem_priv)
 {
 	struct nft_bitmap *priv = nft_set_priv(set);
 	struct nft_bitmap_elem *new = elem->priv, *be;

@@ -132,7 +132,7 @@ static int nft_bitmap_insert(const struct net *net, const struct nft_set *set,
 
 	be = nft_bitmap_elem_find(set, new, genmask);
 	if (be) {
-		*ext = &be->ext;
+		*elem_priv = be;
 		return -EEXIST;
 	}

net/netfilter/nft_set_hash.c +4 -4

index 5a74ee4b7dfb3..60c0d72fb98b1 100644
@@ -168,7 +168,7 @@ static bool nft_rhash_update(struct nft_set *set, const u32 *key,
 
 static int nft_rhash_insert(const struct net *net, const struct nft_set *set,
 			    const struct nft_set_elem *elem,
-			    struct nft_set_ext **ext)
+			    void **elem_priv)
 {
 	struct nft_rhash *priv = nft_set_priv(set);
 	struct nft_rhash_elem *he = elem->priv;

@@ -185,7 +185,7 @@ static int nft_rhash_insert(const struct net *net, const struct nft_set *set,
 	if (IS_ERR(prev))
 		return PTR_ERR(prev);
 	if (prev) {
-		*ext = &prev->ext;
+		*elem_priv = prev;
 		return -EEXIST;
 	}
 	return 0;

@@ -588,7 +588,7 @@ static u32 nft_jhash(const struct nft_set *set, const struct nft_hash *priv,
 
 static int nft_hash_insert(const struct net *net, const struct nft_set *set,
 			   const struct nft_set_elem *elem,
-			   struct nft_set_ext **ext)
+			   void **elem_priv)
 {
 	struct nft_hash_elem *this = elem->priv, *he;
 	struct nft_hash *priv = nft_set_priv(set);

@@ -600,7 +600,7 @@ static int nft_hash_insert(const struct net *net, const struct nft_set *set,
 		if (!memcmp(nft_set_ext_key(&this->ext),
 			    nft_set_ext_key(&he->ext), set->klen) &&
 		    nft_set_elem_active(&he->ext, genmask)) {
-			*ext = &he->ext;
+			*elem_priv = he;
 			return -EEXIST;
 		}
 	}

net/netfilter/nft_set_pipapo.c +5 -5

index 1825db84c2223..ef8441fe586a1 100644
@@ -1233,13 +1233,13 @@ static struct nft_pipapo_match *pipapo_maybe_clone(const struct nft_set *set)
  * @net:	Network namespace
  * @set:	nftables API set representation
  * @elem:	nftables API element representation containing key data
- * @ext2:	Filled with pointer to &struct nft_set_ext in inserted element
+ * @elem_priv:	Filled with private pointer to inserted or existing element
  *
  * Return: 0 on success, error pointer on failure.
  */
 static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 			     const struct nft_set_elem *elem,
-			     struct nft_set_ext **ext2)
+			     void **elem_priv)
 {
 	const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv);
 	union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS];

@@ -1274,7 +1274,7 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 
 		if (!memcmp(start, dup_key->data, sizeof(*dup_key->data)) &&
 		    !memcmp(end, dup_end->data, sizeof(*dup_end->data))) {
-			*ext2 = &dup->ext;
+			*elem_priv = dup;
 			return -EEXIST;
 		}

@@ -1290,7 +1290,7 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 	if (PTR_ERR(dup) != -ENOENT) {
 		if (IS_ERR(dup))
 			return PTR_ERR(dup);
-		*ext2 = &dup->ext;
+		*elem_priv = dup;
 		return -ENOTEMPTY;
 	}

@@ -1352,7 +1352,7 @@ static int nft_pipapo_insert(const struct net *net, const struct nft_set *set,
 		put_cpu_ptr(m->scratch);
 	}
 
-	*ext2 = &e->ext;
+	*elem_priv = e;
 
 	pipapo_map(m, rulemap, e);

net/netfilter/nft_set_rbtree.c +5 -5

index 23e4e656f7f0c..db0ad96d1091e 100644
@@ -319,7 +319,7 @@ static struct nft_rbtree_elem *nft_rbtree_prev_active(struct nft_rbtree_elem *rb
 
 static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 			       struct nft_rbtree_elem *new,
-			       struct nft_set_ext **ext)
+			       void **elem_priv)
 {
 	struct nft_rbtree_elem *rbe, *rbe_le = NULL, *rbe_ge = NULL, *rbe_prev;
 	struct rb_node *node, *next, *parent, **p, *first = NULL;

@@ -437,7 +437,7 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 	 */
 	if (rbe_ge && !nft_rbtree_cmp(set, new, rbe_ge) &&
 	    nft_rbtree_interval_start(rbe_ge) == nft_rbtree_interval_start(new)) {
-		*ext = &rbe_ge->ext;
+		*elem_priv = rbe_ge;
 		return -EEXIST;
 	}

@@ -446,7 +446,7 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 	 */
 	if (rbe_le && !nft_rbtree_cmp(set, new, rbe_le) &&
 	    nft_rbtree_interval_end(rbe_le) == nft_rbtree_interval_end(new)) {
-		*ext = &rbe_le->ext;
+		*elem_priv = rbe_le;
 		return -EEXIST;
 	}

@@ -506,7 +506,7 @@ static int __nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 
 static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 			     const struct nft_set_elem *elem,
-			     struct nft_set_ext **ext)
+			     void **elem_priv)
 {
 	struct nft_rbtree *priv = nft_set_priv(set);
 	struct nft_rbtree_elem *rbe = elem->priv;

@@ -520,7 +520,7 @@ static int nft_rbtree_insert(const struct net *net, const struct nft_set *set,
 
 		write_lock_bh(&priv->lock);
 		write_seqcount_begin(&priv->count);
-		err = __nft_rbtree_insert(net, set, rbe, ext);
+		err = __nft_rbtree_insert(net, set, rbe, elem_priv);
 		write_seqcount_end(&priv->count);
 		write_unlock_bh(&priv->lock);
 	} while (err == -EAGAIN);

Signature · 1 line

2.53.0

Sasha Levin

maintainer

2026-09-30 15:44 UTC #2 lore raw

PATCH 2/2 netfilter: nf_tables: skip expired catchall elements on insert and delete

From: Aohan Mei <[email protected]>

[ Upstream commit 70194dc37670bd08e44b471389861cc01bd3a3c9 ]

nft_setelem_catchall_insert() looks up duplicates with nft_set_elem_active() only, while nft_set_catchall_lookup() and the dump path additionally skip expired elements.

Reported-by TencentOS Corvus AI <[email protected]>

Cc [email protected]

Fixes aaa31047a6d2 ("netfilter: nftables: add catch-all set element support")

Assisted-by CodeBuddy:Kimi-K3

Signed-off-by Aohan Mei <[email protected]>

Signed-off-by Pablo Neira Ayuso <[email protected]>

Signed-off-by Sasha Levin <[email protected]>

---
 net/netfilter/nf_tables_api.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

net/netfilter/nf_tables_api.c +8 -2

index c1dffddd31be6..feb830a78ee3b 100644
@@ -6079,11 +6079,14 @@ static int nft_setelem_catchall_insert(const struct net *net,
 {
 	struct nft_set_elem_catchall *catchall;
 	u8 genmask = nft_genmask_next(net);
+	u64 tstamp = nft_net_tstamp(net);
 	struct nft_set_ext *ext;
 
 	list_for_each_entry(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
-		if (nft_set_elem_active(ext, genmask)) {
+		if (nft_set_elem_active(ext, genmask) &&
+		    !__nft_set_elem_expired(ext, tstamp) &&
+		    !nft_set_elem_is_dead(ext)) {
 			*priv = catchall->elem;
 			return -EEXIST;
 		}

@@ -6144,11 +6147,14 @@ static int nft_setelem_catchall_deactivate(const struct net *net,
 					   struct nft_set_elem *elem)
 {
 	struct nft_set_elem_catchall *catchall;
+	u64 tstamp = nft_net_tstamp(net);
 	struct nft_set_ext *ext;
 
 	list_for_each_entry(catchall, &set->catchall_list, list) {
 		ext = nft_set_elem_ext(set, catchall->elem);
-		if (!nft_is_active_next(net, ext))
+		if (!nft_is_active_next(net, ext) ||
+		    __nft_set_elem_expired(ext, tstamp) ||
+		    nft_set_elem_is_dead(ext))
 			continue;
 
 		kfree(elem->priv);

Signature · 1 line

2.53.0