From nobody Fri Jul 24 22:18:15 2026 Received: from mail-pf1-f181.google.com (mail-pf1-f181.google.com [209.85.210.181]) (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 9491930F534 for ; Wed, 22 Jul 2026 21:03:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.181 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784754237; cv=none; b=YZjzrQrC6oP1tOY5fUSMaASLfAX6/7gBBUTCASNcgJeXbtnIr6Vzxys6cIQltzhnU/wRr/w/lUFtNnWUuWLhrACZ5KtOZSv0hQg+7S1oNW/3vBCTIiRUUEOCvkXB72Bi9EExUUP5SIdoCc8qmb47jzvRYr6UWZ9r6Ioi7wWuTig= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784754237; c=relaxed/simple; bh=Zlb82+IdVuCl9xn/laV+Lll23Ks6kbcvYCU87g1yLoA=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=CSgHI00u++qI6PLnMtiscQxwu9b0iuoU9ykChFg4qtuwA6TjYyR/QmTr+D1OBoBI+XpMdSHWL22t/QRKxLw+vEeA9hGgpYuL8yonm19gNMCldTMsH9gDK5TuPlJwxaEHLu6p9EJOK4gvEZVPMqzOTf5CBSS673Whg2cTzHS2yeQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=asu.edu; spf=pass smtp.mailfrom=asu.edu; dkim=pass (2048-bit key) header.d=asu.edu header.i=@asu.edu header.b=V/9GfggO; arc=none smtp.client-ip=209.85.210.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=asu.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=asu.edu Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=asu.edu header.i=@asu.edu header.b="V/9GfggO" Received: by mail-pf1-f181.google.com with SMTP id d2e1a72fcca58-84a4d8fd6ecso9135212b3a.1 for ; Wed, 22 Jul 2026 14:03:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=asu.edu; s=google; t=1784754236; x=1785359036; 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:content-type; bh=mBm3wrv4Ky7/5MDSknvd1rCNVUs8d17vGheoqukyOXk=; b=V/9GfggOGW1PTz/eGEH+H2Sim0uSRFcV3zQVvh2Bw7Ks+bKaGTJ1BdA+R5FCLIKYnS GGAYIiQdKstOWq9fRyqZq1mdf1kReNP5Izg5FfWNta01i0MRKOt72uYwG0KVSw5pgpM7 ZUXINrtFJRcFy1M7pqeXTsnSmIM+dfISuFYMj3GZKwXVbhqeHmZlxOTvpZp9ipC7e1Wl G4xOmfMlxtkoPUk8D8/nMJj7zb8/tQYqEaAhNdQnXZ+CKhoLaQmeGELN56VuRIidbpAi 8Jn0xuGH3yRmrQ65ZNVx3TlqPjnb9WXNgSAnikz4eN2QLE/BoX9z1ABGU+gt6PMzRXG6 NQzg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1784754236; x=1785359036; 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:content-type; bh=mBm3wrv4Ky7/5MDSknvd1rCNVUs8d17vGheoqukyOXk=; b=sjcqQ/vaTdYRlQcmNd2/8CfaGAE/7OCPBRsQavOC5aL6UfmY0KpwuQxb8I/AYGvPRH 2/whvhnjcP5AWXgAhlj+rQKORdMg171EUrmQqoZlYUr6luYdah4Z14t86Af+NZO7Ti5F 2NdJmoGmJRLXM1rn25RZBp8z4A+OXyUE9khIoze2R6jxm2gO1PWHkPaY6BCEjj2CS9Z0 cXNWFSAacAePriOBJdkDRA1aXeA3usswl2UPuB+Vnxhqn0iOX3uEgmSCrOzHYHreXew6 bXze0po5WNfplfJaD9egaHUUS4VsFUjMYxW1Mz4Xf6DKSyJ24BagCS3Xn9aZSqcDaXo5 XAlg== X-Forwarded-Encrypted: i=1; AHgh+Ro/EqaINl3az8y0+b0pqxqUf3Ngc3OCtF/hHMxTzGjikZMaGVZB+TUae/mw3eVdhC0Yn4hYpIYicm+Coww=@vger.kernel.org X-Gm-Message-State: AOJu0YygFqUyMZCvXvWF2856NXJrNq/d8Gv44F+r/tKzx0YD3fPTu89u ZeC0DOiLSdY00P8oFoS9XLM709bENo00avR0rLHBN2X58WuSIfsjOiKLipSladnHbQlWSbq9S8t j+dplxg== X-Gm-Gg: AR+sD136893J1aNEZWNheB4VqKRlhQ1GjYR+EA+LJuU6VOqkZK77uMvYXQcwIENq++d qdfT0U1XcvhwrejjXBL+3UxhNlKRhuLQ/l5exZ15i11cuftdrZAe+8mWk2jHRbhcC6AowJnZJZ3 tzsmOO5DGiJ+Vvjp7+wTic0c4WIVVzLS8it98vPUVdDkcknPk0i1ixs4z1R8iC4Pxf7KwDLi6OQ h/EPasi2ZvHDuUOcXg4lfbSZytBq9dfruy/JPsR+JUvpmEOeeMl3IaYCR9d45X/u7Gf++jKgXVZ E9wWd2Kj6xMonPUq9NQjQQhQaPqfGqOeiTE9buIVHgbPLFCCqt5C9WjUF9DnVRFqM/YUIxO56xZ 9Jt7ULxCHV3la9npNsjwFnXxGD/rqk8PnrRSqpdcVHXM+2P+nHMjy8L4Ep6ZvRw== X-Received: by 2002:a05:6a00:2d1a:b0:848:2a55:7110 with SMTP id d2e1a72fcca58-84e2bb53625mr447822b3a.36.1784754235842; Wed, 22 Jul 2026 14:03:55 -0700 (PDT) Received: from p1.. ([2607:fb91:1582:c77:30c3:296e:133d:928d]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-84e175a3d6csm1839028b3a.40.2026.07.22.14.03.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Jul 2026 14:03:55 -0700 (PDT) From: Xiang Mei To: Jakub Kicinski , Allison Henderson , "David S . Miller" , Eric Dumazet , Paolo Abeni , Simon Horman Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, rds-devel@oss.oracle.com, linux-kernel@vger.kernel.org, Santosh Shilimkar , Ka-Cheong Poon , Ilia Gavrilov , bestswngs@gmail.com, Xiang Mei Subject: [PATCH net v4] rds: tcp: hold the RCU lock across ipv6_chk_addr() in rds_tcp_laddr_check() Date: Wed, 22 Jul 2026 14:02:03 -0700 Message-ID: <20260722210203.565803-1-xmei5@asu.edu> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" rds_tcp_laddr_check() looks up a scoped IPv6 interface with dev_get_by_index_rcu(), drops the RCU read-side lock, and only then passes the bare struct net_device * into ipv6_chk_addr(). dev_get_by_index_rcu() only keeps the device alive within the same RCU read-side section. After rcu_read_unlock(), a concurrent RTM_DELLINK can free the net_device; ipv6_chk_addr() then dereferences the stale pointer in __ipv6_chk_addr_and_flags() (e.g. l3mdev_master_dev_rcu(dev)), reading freed memory. Keep the RCU read-side lock held across the ipv6_chk_addr() call instead of dropping it right after the lookup, so the device cannot be freed while it is in use. BUG: KASAN: slab-use-after-free in __ipv6_chk_addr_and_flags (... net/ipv= 6/addrconf.c:1998) Read of size 8 at addr ffff8880106ec000 by task exploit/153 Call Trace: ... kasan_report (mm/kasan/report.c:595) __ipv6_chk_addr_and_flags (... net/ipv6/addrconf.c:1998) ipv6_chk_addr (net/ipv6/addrconf.c:2031 net/ipv6/addrconf.c:1972) rds_tcp_laddr_check (net/rds/tcp.c:370) rds_bind (net/rds/bind.c:248) __sys_bind (net/socket.c:1920) __x64_sys_bind (net/socket.c:1956) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:121) Fixes: eee2fa6ab322 ("rds: Changing IP address internal representation to s= truct in6_addr") Reported-by: Weiming Shi Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Xiang Mei Reviewed-by: Allison Henderson --- v2: Use rcu_read_locks and rebase on rds: Fix inet6_addr_lst NULL dereference when IPv6 is disabled v3: Add change log to commit message as Allison suggested v4: remove the changelog in the commit message since that was my misunderst= anding net/rds/tcp.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/net/rds/tcp.c b/net/rds/tcp.c index 955d92277d5a..30cfb0087f2c 100644 --- a/net/rds/tcp.c +++ b/net/rds/tcp.c @@ -355,23 +355,25 @@ int rds_tcp_laddr_check(struct net *net, const struct= in6_addr *addr, /* If the scope_id is specified, check only those addresses * hosted on the specified interface. */ + rcu_read_lock(); if (scope_id !=3D 0) { - rcu_read_lock(); dev =3D dev_get_by_index_rcu(net, scope_id); /* scope_id is not valid... */ if (!dev) { rcu_read_unlock(); return -EADDRNOTAVAIL; } - rcu_read_unlock(); } #if IS_ENABLED(CONFIG_IPV6) if (ipv6_mod_enabled()) { ret =3D ipv6_chk_addr(net, addr, dev, 0); - if (ret) + if (ret) { + rcu_read_unlock(); return 0; + } } #endif + rcu_read_unlock(); return -EADDRNOTAVAIL; } =20 --=20 2.43.0