From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f175.google.com (mail-pf1-f175.google.com [209.85.210.175]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 36DE82DEA75 for ; Tue, 30 Jun 2026 08:42:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.175 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782808950; cv=none; b=K3810z81zhC/5cUcO3KyMxcAMvu/IkT/oYV5XiSXLUR5fK5LG5euyI266vKR8DIaLq/lkG+tboRZlXLCUwUWZVGhWWmrGL3RfBUXfii8TqxA5zKf2KDjyHTpP/TnqARfjNcVnOW3xmzdYV1A62otmZHc6xD9orNY5kSgRCBDUdY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782808950; c=relaxed/simple; bh=j8zqaB7T04hBpqZcwzgtw7u5iuAAhaaqsYCQfcZUNBo=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=cT7n7+5BS6uzsJVEpfTIQ8Wed378Jhx9JqUGhw+iL6A6f8feMj4BuwKFaX05KpYx7HqhVjRERsYLPsKn4xMJ1HlNiFiUImFmPfgi8cUXuwSUqnQlUxbWObggq3XIg0eHpom6tlWskGF8dibplnRcZJpU+H/qnBkHmF/py9rS5O0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=UJFsstUP; arc=none smtp.client-ip=209.85.210.175 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="UJFsstUP" Received: by mail-pf1-f175.google.com with SMTP id d2e1a72fcca58-8424b00710aso2972715b3a.0 for ; Tue, 30 Jun 2026 01:42:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1782808947; x=1783413747; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=d7EeC63NFPzYUKRtuwuPqf7M5up4qWTV1M2HoxWcbP8=; b=UJFsstUPwLa724WNigvYHuUP+tM480v4gNbcwvmcolSgODF7338lMEfnbHD6cGk/Ym 7S9ZMWNUyIOTc0lQkPM+edE2wZo+469yFBuhvbbSA+Z6ILYCl3CgWdHamALQNnJLxiUG e5FpRhdkuwhyQhrDWyY6ZI3oazdVxEcMHYqCPswmrI7bQZH67Lrh1SHCtk3Gu2BTRwPa xXfaou3yadsV1000g8ipqNgOnDj0e6yzOppaPl5Ou2gtJIDQwYbL/LZvgkIXha4Vn+6D df7bljFeXUI2qTFw/SLk1D5usNVwqFz4a99B74cNY7PGvgifYzP1lIbpm1LeA7C19si+ 02Gw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1782808947; x=1783413747; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=d7EeC63NFPzYUKRtuwuPqf7M5up4qWTV1M2HoxWcbP8=; b=eQDURGnaI9fv+NlbQ0Ij5fVHDb2OFaONPTbCV3zNo5Ucg8vYKlcbKEa4FObgVB/qCb lOURLoeudG4Q61GogunJkF6cR+NAcXnBwOzoxTVuFQWLM5UoxjpH6gltANN9hX48R3e2 0JzsL5uI9GaKRetDIDJs9gVL+fY+ZdQawbrmRI7nDJWSHTsg+9j+4oGNS8USbIL9ugu2 9UqtYRZ+MmKXWTvlkkX3YKElAt+i8Azh/KEbx73OVqwoTOxHkLgvl5HHtHRrsuhACWkI /sUXZQu68x7lMoKTxHA83MerDDlgYR5vKELleqdaccXSgGHkUW1h23pqDzRvXYG7MSQu VOgQ== X-Forwarded-Encrypted: i=1; AFNElJ+8PqyClRpfigpU332QARbKRW+SpJS4nGQW92tDtLXEEKAzO5rytNNM40/KI2AaispZ+LEZ0r8=@vger.kernel.org X-Gm-Message-State: AOJu0YyBQPaAvxQTRXYsrEY4eDngVWd93NDUjvq5RBVGErbkY5EWFn+t MXWmzUE/RSn9iLL1lY5Ax2qA6S3gPwsMtkqkd353AwL05kwUVfH1/2bQ X-Gm-Gg: AfdE7cnXyp1Fgmw+d9L9K5cuKS3pDeoUYwXL+JA2hJ6kvf23I/aQeqSVN1reemuCAvU wEMH6lYPuA16wNOcOZGNTdFiWYw4mGupc3stfv4k5VVFalC8WZ9FNBELIivX4xm/DERHPOxi4O8 hJLLWro+owvPUjHXfvRPXHtuYxyJd6sZcTbarmPdVQ5gn0sFzBNQtchV3vlyiKt6A8IaklKfkWg G88aHo8RKx5OBmCkH5QWaxo3OtkYWsJ/RTBxmVbtcWVxTbEgT35b4OvmTJ9fcZRDSn1zd6jmFrS VRjGkqxUTcd5xvc0e3D0S3+dmoaeyKWykclA/jyDv22eTQSJ5qOZoq+Ngy1TlacYTQJ75QQ5fkT mPr4rseP2EABT5J5YTz4PffXwK797lgtZVGhSg5UT7SI37PKWA6kG2KP4ogcN5iDxRH8AjBbIdL huOMrx9ivEiyXR8Xx13SfrUE63SjoTlobjkKULjg== X-Received: by 2002:a05:6a00:3e21:b0:845:cd11:37e8 with SMTP id d2e1a72fcca58-8479f1155ecmr2288803b3a.24.1782808947354; Tue, 30 Jun 2026 01:42:27 -0700 (PDT) Received: from online.mioffice.cn ([43.224.245.228]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-847a02d1597sm1456636b3a.31.2026.06.30.01.42.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 30 Jun 2026 01:42:26 -0700 (PDT) From: Pengfei Zhang To: dsahern@kernel.org, idosch@nvidia.com Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, horms@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, chenzhangqi@xiaomi.com, baohua@kernel.org, zhangpengfei16@xiaomi.com, Pengfei Zhang Subject: [PATCH v2 net-next] ipv4: fib: fix route re-dump in inet_dump_fib() on multi-batch dump Date: Tue, 30 Jun 2026 16:42:20 +0800 Message-ID: <20260630084220.2711025-1-zhangfeionline@gmail.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit inet_dump_fib() saves its progress in cb->args[1] as a positional index within the current hash chain. Between batches, a concurrent fib_new_table() can insert a new table at the chain head, shifting all existing entries. On resume the saved index lands on a different table, causing already-dumped tables to be re-dumped and the originally suspended table to restart from the beginning. Fix by storing tb->tb_id in cb->args[1] instead of a positional index, mirroring the fix applied to inet6_dump_fib() in commit 9facb861dc6b ("ipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump"). Signed-off-by: Pengfei Zhang --- v2: - Drop Fixes tag (not needed for net-next) - Fix variable declaration order (reverse xmas tree) - Reference IPv6 fix commit hash v1: https://lore.kernel.org/netdev/20260626085636.1524451-1-zhangfeionline@gmail.com/ net/ipv4/fib_frontend.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c index 42212970d..248895e7e 100644 --- a/net/ipv4/fib_frontend.c +++ b/net/ipv4/fib_frontend.c @@ -1019,10 +1019,11 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) .dump_routes = true, .dump_exceptions = true, }; - unsigned int e = 0, s_e, h, s_h; struct hlist_head *head; int dumped = 0, err = 0; struct fib_table *tb; + unsigned int h, s_h; + u32 s_id; rcu_read_lock(); if (cb->strict_check) { @@ -1054,29 +1055,28 @@ static int inet_dump_fib(struct sk_buff *skb, struct netlink_callback *cb) } s_h = cb->args[0]; - s_e = cb->args[1]; + s_id = cb->args[1]; err = 0; - for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_e = 0) { - e = 0; + for (h = s_h; h < FIB_TABLE_HASHSZ; h++, s_id = 0) { head = &net->ipv4.fib_table_hash[h]; hlist_for_each_entry_rcu(tb, head, tb_hlist) { - if (e < s_e) - goto next; + if (s_id && tb->tb_id != s_id) + continue; + + s_id = 0; if (dumped) memset(&cb->args[2], 0, sizeof(cb->args) - 2 * sizeof(cb->args[0])); + cb->args[1] = tb->tb_id; err = fib_table_dump(tb, skb, cb, &filter); if (err < 0) goto out; dumped = 1; -next: - e++; } } out: - cb->args[1] = e; cb->args[0] = h; unlock: -- 2.54.0