From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A585A1CDFAC; Sun, 7 Sep 2025 20:12:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757275930; cv=none; b=PWcG87okyI8BT4tEpccATU1YInmI3gjJY8Eexqwg03noY5tV9DavUKWGKsPrzdyPOjUKYvYOQDgrK7tAlitT0AMu3bZnOVmDlwN4bvf9TPxSe3FFdWANB96ifpzuy08V/ilPK72GLEHLsOy7kDyUUKYsmoHvfvZWR896IaZaUz0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757275930; c=relaxed/simple; bh=RVYWxlYtKQvEaTBtQfGT0piYrwf+oVdcBxMCFTgDGSM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B7YLgTI04iCwD7Z9oZbWCi7IIW+yhIkYdwnIi+P+AVr9e7Anxmkd0VFIa+cvNwWpKRQBJnwAG8jioBr7iVUjsXBx+V1YJx5Qh7UeTtZuzCZ39dbNXSKB4eR+CtQxIfU57AxC3K5peg6wwy+vW5VLVf3i26tqACmP2y1OwVFi4xc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=MiYETvE6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="MiYETvE6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2BF8BC4CEF0; Sun, 7 Sep 2025 20:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1757275930; bh=RVYWxlYtKQvEaTBtQfGT0piYrwf+oVdcBxMCFTgDGSM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MiYETvE6KOBtFqE6Gaht7pSxb3HAgFq5tqCHst+j/S4axeFuG+X4R9VQuCV2qOnrs Bbpc4gTNphtCr0TGIwwCT6bMBYVEKImyLsqas/iN+uedSQYryloGSB4l6bGsOJSbou 2oGGJWs3NVOz5PgxMzL5jS3fsvwR/EwxjSf4V1jo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Florian Westphal , Wang Liang , Sasha Levin Subject: [PATCH 5.15 10/64] netfilter: br_netfilter: do not check confirmed bit in br_nf_local_in() after confirm Date: Sun, 7 Sep 2025 21:57:52 +0200 Message-ID: <20250907195603.691225386@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20250907195603.394640159@linuxfoundation.org> References: <20250907195603.394640159@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Wang Liang [ Upstream commit 479a54ab92087318514c82428a87af2d7af1a576 ] When send a broadcast packet to a tap device, which was added to a bridge, br_nf_local_in() is called to confirm the conntrack. If another conntrack with the same hash value is added to the hash table, which can be triggered by a normal packet to a non-bridge device, the below warning may happen. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 96 at net/bridge/br_netfilter_hooks.c:632 br_nf_local_in+0x168/0x200 CPU: 1 UID: 0 PID: 96 Comm: tap_send Not tainted 6.17.0-rc2-dirty #44 PREEMPT(voluntary) RIP: 0010:br_nf_local_in+0x168/0x200 Call Trace: nf_hook_slow+0x3e/0xf0 br_pass_frame_up+0x103/0x180 br_handle_frame_finish+0x2de/0x5b0 br_nf_hook_thresh+0xc0/0x120 br_nf_pre_routing_finish+0x168/0x3a0 br_nf_pre_routing+0x237/0x5e0 br_handle_frame+0x1ec/0x3c0 __netif_receive_skb_core+0x225/0x1210 __netif_receive_skb_one_core+0x37/0xa0 netif_receive_skb+0x36/0x160 tun_get_user+0xa54/0x10c0 tun_chr_write_iter+0x65/0xb0 vfs_write+0x305/0x410 ksys_write+0x60/0xd0 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x77/0x7f ---[ end trace 0000000000000000 ]--- To solve the hash conflict, nf_ct_resolve_clash() try to merge the conntracks, and update skb->_nfct. However, br_nf_local_in() still use the old ct from local variable 'nfct' after confirm(), which leads to this warning. If confirm() does not insert the conntrack entry and return NF_DROP, the warning may also occur. There is no need to reserve the WARN_ON_ONCE, just remove it. Link: https://lore.kernel.org/netdev/20250820043329.2902014-1-wangliang74@huawei.com/ Fixes: 62e7151ae3eb ("netfilter: bridge: confirm multicast packets before passing them up the stack") Suggested-by: Florian Westphal Signed-off-by: Wang Liang Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/bridge/br_netfilter_hooks.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/net/bridge/br_netfilter_hooks.c b/net/bridge/br_netfilter_hooks.c index 7cd2bef583312..9ad0feb248b5d 100644 --- a/net/bridge/br_netfilter_hooks.c +++ b/net/bridge/br_netfilter_hooks.c @@ -630,9 +630,6 @@ static unsigned int br_nf_local_in(void *priv, break; } - ct = container_of(nfct, struct nf_conn, ct_general); - WARN_ON_ONCE(!nf_ct_is_confirmed(ct)); - return ret; } #endif -- 2.50.1