From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EDC7F383300; Sun, 13 Sep 2026 20:55:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.70.190.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789332907; cv=none; b=iVABLTfojNlV4oJEBRLJNSdciSqm1MrGjoouiAPLNss5yHjANPI2RkNyldcFBMvWJ3Vd9TWxQkQGEx84rxR8+Ofqj7SqL89HPMr+6Zt9fvfM2bZjb7HrPjlEFG5QeWw0QlW8N2Hy34vlRINtf6ffB5gvfR5izATUcbgF3yYkA94= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789332907; c=relaxed/simple; bh=HYcqT1RRpPWrPjRgsoRjWlMz9mkzCzVDAcgANm5l7ik=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=O7RdsH1BfrKqTElC+x8dHFrUXtEbTBc0OSfy/uGOBAnEg1zm551Te0cpPd2AvlS8VJPwUPIzxrjBm/DTYv3srMvo/KUI0kmvDQHPTwVn/5/SrH3OcVQHFxzBkUXRWWDnAhXfxqDqK1HkbaHxAIlDW5Y+rpWspaoL274r1ndFtWY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b=DMAw56Ud; arc=none smtp.client-ip=217.70.190.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.b="DMAw56Ud" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1789332898; bh=mgUL1pj5GumT5FyU/5MP+viMXx/+3FUen6Uwb/NhO9U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DMAw56Ud+LrJpnEsGyFdUgcJh7/iKXOGlZX+dT6zfYPIrxy+mGEWNX2JzpMVL+ICG RqGWnqw9x+NKTH9wMuh91ogpbEhBVyGVGlyj8CqzZsyx8GUMxvBDWec7UCrIFAbCHs +uMLuKv2JOhJsXQKi3nYJHVbvC0e0IHUSE9jkbGnRMPXDzmv6NYlbzf8mZl6bkdXhN kOtEjGeTzmJ+ma78UEvhh64xxyN1GK6DOZ85AUKb4lyQm3YD9cS66FyxZ0eW+3xdun Szmmo2KFEhny3VeWYDHINZBEqM2I0yhzxffxpzmQtmY4SpTVzzNc7W+z6Bnu5MAkRQ lXhkmapiGv5vA== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 57B276005A; Sun, 13 Sep 2026 22:54:58 +0200 (CEST) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@google.com, horms@kernel.org, fw@strlen.de, ja@ssi.bg Subject: [PATCH net 2/4] netfilter: nf_tables: fix device name and prefix match in hook lookup Date: Sun, 13 Sep 2026 22:54:45 +0200 Message-ID: <20260913205447.1889203-3-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260913205447.1889203-1-pablo@netfilter.org> References: <20260913205447.1889203-1-pablo@netfilter.org> Precedence: bulk X-Mailing-List: netfilter-devel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Fernando Fernandez Mancera Currently, a netdev chain or flowtable hooked to a device prefix can be unintentionally deleted by a control-plane request targeting an exact device name or even a shorter one due to the usage of min() to calculate the length to match. Fix this by making sure an exact device match never matches a prefix and that both the target and the candidate have the same length during delete operation. The add and update paths retain the existing overlap matching to prevent a single device from matching multiple hooks. Reported-by: Wei Fang Closes: https://lore.kernel.org/netfilter-devel/CANE+tVrDeNCHQVmsqkV2ozeBqyE3GtRDMhZgsg1bhw10yGNTRQ@mail.gmail.com/ Fixes: 6d07a289504a ("netfilter: nf_tables: Support wildcard netdev hook specs") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 31fbd5a28937..c0b754a2d45b 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2440,11 +2440,14 @@ static struct nft_hook *nft_netdev_hook_alloc(struct net *net, } static struct nft_hook *nft_hook_list_find(struct list_head *hook_list, - const struct nft_hook *this) + const struct nft_hook *this, + bool strict) { struct nft_hook *hook; list_for_each_entry(hook, hook_list, list) { + if (strict && hook->ifnamelen != this->ifnamelen) + continue; if (!strncmp(hook->ifname, this->ifname, min(hook->ifnamelen, this->ifnamelen))) { if (hook->flags & NFT_HOOK_REMOVE) @@ -2486,7 +2489,7 @@ static int nf_tables_parse_netdev_hooks(struct net *net, err = PTR_ERR(hook); goto err_hook; } - if (nft_hook_list_find(hook_list, hook)) { + if (nft_hook_list_find(hook_list, hook, false)) { NL_SET_BAD_ATTR(extack, tmp); nft_netdev_hook_free(hook); err = -EEXIST; @@ -2943,7 +2946,7 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, ops->hook = basechain->ops.hook; } - if (nft_hook_list_find(&basechain->hook_list, h)) { + if (nft_hook_list_find(&basechain->hook_list, h, false)) { list_del(&h->list); nft_netdev_hook_free(h); continue; @@ -2956,7 +2959,8 @@ static int nf_tables_updchain(struct nft_ctx *ctx, u8 genmask, u8 policy, !nft_trans_chain_update(trans)) continue; - if (nft_hook_list_find(&nft_trans_chain_hooks(trans), h)) { + if (nft_hook_list_find(&nft_trans_chain_hooks(trans), + h, false)) { nft_chain_release_hook(&hook); return -EEXIST; } @@ -3257,7 +3261,7 @@ static int nft_delchain_hook(struct nft_ctx *ctx, return err; list_for_each_entry(this, &chain_hook.list, list) { - hook = nft_hook_list_find(&basechain->hook_list, this); + hook = nft_hook_list_find(&basechain->hook_list, this, true); if (!hook) { err = -ENOENT; goto err_chain_del_hook; @@ -9053,7 +9057,7 @@ static int nft_register_flowtable_net_hooks(struct net *net, if (!nft_is_active_next(net, ft)) continue; - if (nft_hook_list_find(&ft->hook_list, hook)) { + if (nft_hook_list_find(&ft->hook_list, hook, false)) { err = -EEXIST; goto err_unregister_net_hooks; } @@ -9130,7 +9134,7 @@ static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh, return err; list_for_each_entry_safe(hook, next, &flowtable_hook.list, list) { - if (nft_hook_list_find(&flowtable->hook_list, hook)) { + if (nft_hook_list_find(&flowtable->hook_list, hook, false)) { list_del(&hook->list); nft_netdev_hook_free(hook); continue; @@ -9143,7 +9147,7 @@ static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh, !nft_trans_flowtable_update(trans)) continue; - if (nft_hook_list_find(&nft_trans_flowtable_hooks(trans), hook)) { + if (nft_hook_list_find(&nft_trans_flowtable_hooks(trans), hook, false)) { err = -EEXIST; goto err_flowtable_update_hook; } @@ -9363,7 +9367,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx, return err; list_for_each_entry(this, &flowtable_hook.list, list) { - hook = nft_hook_list_find(&flowtable->hook_list, this); + hook = nft_hook_list_find(&flowtable->hook_list, this, true); if (!hook) { err = -ENOENT; goto err_flowtable_del_hook; -- 2.47.3