From nobody Thu Sep 19 19:24:04 2024 Received: from mailgw02.mediatek.com (unknown [210.61.82.184]) (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 1595A446A9; Wed, 15 May 2024 07:37:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=210.61.82.184 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715758658; cv=none; b=ixNdNVI5Uzek/a/XVrp0PgrCP17DcMTIOVb4c9n+e07VOk5Dr4mphvIGXVPdyucS9aRVatsSqosDGcl32KV4CK/mmWd0neroRJsKLK83/TNmIhHKy2WbSswm9XlWDTMKlFK0csxwpD4hbcUxcdCaRJQyAU8/QISZzjkTqSVgq60= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715758658; c=relaxed/simple; bh=bEsm0BbBd0A7B3bKfe/HOWTX8J9AFW5GwUZfH8pzidE=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=S7oMpJglQRO7eiyREKwaQwyh6jxcNDWyuJu2471FNHJIPAXwmyayqN8E/WvuQBiIXSkRdAb01x5v9pxvPA3qnPl10HiYbY1O/KYz0hNEFSZDsje1UBf9f+UpXrORux9B8QUF9RvZ9aa+jWrLKtxlvNLsPoILraPwsAdSSAwLj94= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com; spf=pass smtp.mailfrom=mediatek.com; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b=QVrXSJBe; arc=none smtp.client-ip=210.61.82.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=mediatek.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=mediatek.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=mediatek.com header.i=@mediatek.com header.b="QVrXSJBe" X-UUID: f8460486128d11ef8065b7b53f7091ad-20240515 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=mediatek.com; s=dk; h=Content-Type:MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:CC:To:From; bh=7aeri6oYG4BXYXoTQ2cZONHGAN6C/zuDSGpOZpExbAw=; b=QVrXSJBegMdpAiH/FpiwRNO6CWpftak62qh65/YTVsENLL+2zAmZBmQUUIwWUKv2PQ/kDibHg9IfCRYXszll+xzP03W/5Ib41++2nkG33HeTgp2FPgqYpkM1covTaP1IIoCcvCex1KTtJDWWBJ5+9+cEfpX8mGGVr58Bf3aJLQQ=; X-CID-P-RULE: Release_Ham X-CID-O-INFO: VERSION:1.1.38,REQID:7c88c58a-e253-4fe5-be09-35a6985de4e1,IP:0,U RL:0,TC:0,Content:-25,EDM:0,RT:0,SF:0,FILE:0,BULK:0,RULE:Release_Ham,ACTIO N:release,TS:-25 X-CID-META: VersionHash:82c5f88,CLOUDID:729ee083-4f93-4875-95e7-8c66ea833d57,B ulkID:nil,BulkQuantity:0,Recheck:0,SF:102,TC:nil,Content:0,EDM:-3,IP:nil,U RL:1,File:nil,RT:nil,Bulk:nil,QS:nil,BEC:nil,COL:0,OSI:0,OSA:0,AV:0,LES:1, SPR:NO,DKR:0,DKP:0,BRR:0,BRE:0 X-CID-BVR: 0,NGT X-CID-BAS: 0,NGT,0,_ X-CID-FACTOR: TF_CID_SPAM_SNR,TF_CID_SPAM_ULS X-UUID: f8460486128d11ef8065b7b53f7091ad-20240515 Received: from mtkmbs09n1.mediatek.inc [(172.21.101.35)] by mailgw02.mediatek.com (envelope-from ) (Generic MTA with TLSv1.2 ECDHE-RSA-AES256-GCM-SHA384 256/256) with ESMTP id 995212172; Wed, 15 May 2024 15:37:23 +0800 Received: from mtkmbs13n1.mediatek.inc (172.21.101.193) by MTKMBS09N2.mediatek.inc (172.21.101.94) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Wed, 15 May 2024 00:37:22 -0700 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkmbs13n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Wed, 15 May 2024 15:37:22 +0800 From: Yenchia Chen To: CC: Eric Dumazet , Jakub Kicinski , "yenchia . chen" , "David S. Miller" , Matthias Brugger , Sasha Levin , Simon Horman , Ryosuke Yasuoka , Zhengchao Shao , Pedro Tammela , Thomas Graf , , , , Subject: [PATCH 5.15 1/2] netlink: annotate lockless accesses to nlk->max_recvmsg_len Date: Wed, 15 May 2024 15:36:37 +0800 Message-ID: <20240515073644.32503-2-yenchia.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20240515073644.32503-1-yenchia.chen@mediatek.com> References: <20240515073644.32503-1-yenchia.chen@mediatek.com> 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" From: Eric Dumazet syzbot reported a data-race in data-race in netlink_recvmsg() [1] Indeed, netlink_recvmsg() can be run concurrently, and netlink_dump() also needs protection. [1] BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg read to 0xffff888141840b38 of 8 bytes by task 23057 on cpu 0: netlink_recvmsg+0xea/0x730 net/netlink/af_netlink.c:1988 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg net/socket.c:1038 [inline] __sys_recvfrom+0x1ee/0x2e0 net/socket.c:2194 __do_sys_recvfrom net/socket.c:2212 [inline] __se_sys_recvfrom net/socket.c:2208 [inline] __x64_sys_recvfrom+0x78/0x90 net/socket.c:2208 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd write to 0xffff888141840b38 of 8 bytes by task 23037 on cpu 1: netlink_recvmsg+0x114/0x730 net/netlink/af_netlink.c:1989 sock_recvmsg_nosec net/socket.c:1017 [inline] sock_recvmsg net/socket.c:1038 [inline] ____sys_recvmsg+0x156/0x310 net/socket.c:2720 ___sys_recvmsg net/socket.c:2762 [inline] do_recvmmsg+0x2e5/0x710 net/socket.c:2856 __sys_recvmmsg net/socket.c:2935 [inline] __do_sys_recvmmsg net/socket.c:2958 [inline] __se_sys_recvmmsg net/socket.c:2951 [inline] __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x0000000000000000 -> 0x0000000000001000 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 23037 Comm: syz-executor.2 Not tainted 6.3.0-rc4-syzkaller-0019= 5-g5a57b48fdfcb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Goo= gle 03/02/2023 Fixes: 9063e21fb026 ("netlink: autosize skb lengthes") Reported-by: syzbot Signed-off-by: Eric Dumazet Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20230403214643.768555-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: yenchia.chen Reviewed-by: Carlos Llamas --- net/netlink/af_netlink.c | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 82df02695bbd..56ba8a6396ca 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -1935,7 +1935,7 @@ static int netlink_recvmsg(struct socket *sock, struc= t msghdr *msg, size_t len, struct sock *sk =3D sock->sk; struct netlink_sock *nlk =3D nlk_sk(sk); int noblock =3D flags & MSG_DONTWAIT; - size_t copied; + size_t copied, max_recvmsg_len; struct sk_buff *skb, *data_skb; int err, ret; =20 @@ -1968,9 +1968,10 @@ static int netlink_recvmsg(struct socket *sock, stru= ct msghdr *msg, size_t len, #endif =20 /* Record the max length of recvmsg() calls for future allocations */ - nlk->max_recvmsg_len =3D max(nlk->max_recvmsg_len, len); - nlk->max_recvmsg_len =3D min_t(size_t, nlk->max_recvmsg_len, - SKB_WITH_OVERHEAD(32768)); + max_recvmsg_len =3D max(READ_ONCE(nlk->max_recvmsg_len), len); + max_recvmsg_len =3D min_t(size_t, max_recvmsg_len, + SKB_WITH_OVERHEAD(32768)); + WRITE_ONCE(nlk->max_recvmsg_len, max_recvmsg_len); =20 copied =3D data_skb->len; if (len < copied) { @@ -2219,6 +2220,7 @@ static int netlink_dump(struct sock *sk) struct netlink_ext_ack extack =3D {}; struct netlink_callback *cb; struct sk_buff *skb =3D NULL; + size_t max_recvmsg_len; struct module *module; int err =3D -ENOBUFS; int alloc_min_size; @@ -2241,8 +2243,9 @@ static int netlink_dump(struct sock *sk) cb =3D &nlk->cb; alloc_min_size =3D max_t(int, cb->min_dump_alloc, NLMSG_GOODSIZE); =20 - if (alloc_min_size < nlk->max_recvmsg_len) { - alloc_size =3D nlk->max_recvmsg_len; + max_recvmsg_len =3D READ_ONCE(nlk->max_recvmsg_len); + if (alloc_min_size < max_recvmsg_len) { + alloc_size =3D max_recvmsg_len; skb =3D alloc_skb(alloc_size, (GFP_KERNEL & ~__GFP_DIRECT_RECLAIM) | __GFP_NOWARN | __GFP_NORETRY); --=20 2.18.0 From nobody Thu Sep 19 19:24:04 2024 Received: from mailgw01.mediatek.com (unknown [60.244.123.138]) (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 E756744C67; Wed, 15 May 2024 07:37:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=60.244.123.138 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715758661; cv=none; b=uYo7osPvl8vzr4gjRONvXa4RAQDLD/yXelRpFVM6iUeyoyoOAJLFIq0MWzw/rZ7NP79ZMTPG79K2xnrezTaD6Eetu50uWEBJ0lZZCZXtPBX3wsEgJro4Hv7BQReA4/IELjiybcdqwdxpUyM5wTHOgaA65AXWbgdzLopmpZT5yA4= ARC-Message-Signature: i=1; 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Wed, 15 May 2024 15:37:32 +0800 Received: from mtkmbs13n1.mediatek.inc (172.21.101.193) by MTKMBS14N1.mediatek.inc (172.21.101.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.26; Wed, 15 May 2024 15:37:27 +0800 Received: from mtksdccf07.mediatek.inc (172.21.84.99) by mtkmbs13n1.mediatek.inc (172.21.101.73) with Microsoft SMTP Server id 15.2.1118.26 via Frontend Transport; Wed, 15 May 2024 15:37:27 +0800 From: Yenchia Chen To: CC: Eric Dumazet , Jakub Kicinski , "yenchia . chen" , "David S. Miller" , Matthias Brugger , Sasha Levin , Simon Horman , Zhengchao Shao , Pedro Tammela , "Ryosuke Yasuoka" , Thomas Graf , , , , Subject: [PATCH 5.15 2/2] netlink: annotate data-races around sk->sk_err Date: Wed, 15 May 2024 15:36:38 +0800 Message-ID: <20240515073644.32503-3-yenchia.chen@mediatek.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20240515073644.32503-1-yenchia.chen@mediatek.com> References: <20240515073644.32503-1-yenchia.chen@mediatek.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-Product-Ver: SMEX-14.0.0.3152-9.1.1006-23728.005 X-TM-AS-Result: No-10-0.131400-8.000000 X-TMASE-MatchedRID: B4VcMIpPJ80Rj//xa6LvPpRrnSy7UTtbKx5ICGp/WtHMcZL/toKwUkrQ UCy1ylPSAPcZ9zzfLcIv7hNVwd55efuyoboeSVFgTb17VOdIjbvwq1JQ5xF4kkYvSDWdWaRhzTO MdSL65dE+pUh4aRsT8NseKHBzEjWEkKjL2IOi2LCXIjSc2qlF9V3KZkFy4YZELi8ZclgvHlpZzl 8EYQ5IaIW41t/bx9voj544a0UVEb2XKs94NAOH8p4CIKY/Hg3Am4n49vyf9XFKdDgyPBo71yq2r l3dzGQ1NSaQQEldMgqmSHBo/u5geQuOoM9Ul2SnBc7tWkpxW0LdJINzPCIf61dBVVovJ3TSNzbL S7IGtHHBIEfdl1Dl4xaNTUyr3lsN/GNoswKabLcXRoPmWO3jekxwdkPqCq7vDEyN+J8hd+jCS9W gDXVPCok0oJvJCVSkQwymtxuJ6y0= X-TM-AS-User-Approved-Sender: No X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10-0.131400-8.000000 X-TMASE-Version: SMEX-14.0.0.3152-9.1.1006-23728.005 X-TM-SNTS-SMTP: 39C47996367777646C92F12D7CAC304752903E36B1A15F34117C76253C3414C22000:8 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Eric Dumazet syzbot caught another data-race in netlink when setting sk->sk_err. Annotate all of them for good measure. BUG: KCSAN: data-race in netlink_recvmsg / netlink_recvmsg write to 0xffff8881613bb220 of 4 bytes by task 28147 on cpu 0: netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994 sock_recvmsg_nosec net/socket.c:1027 [inline] sock_recvmsg net/socket.c:1049 [inline] __sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229 __do_sys_recvfrom net/socket.c:2247 [inline] __se_sys_recvfrom net/socket.c:2243 [inline] __x64_sys_recvfrom+0x78/0x90 net/socket.c:2243 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd write to 0xffff8881613bb220 of 4 bytes by task 28146 on cpu 1: netlink_recvmsg+0x448/0x780 net/netlink/af_netlink.c:1994 sock_recvmsg_nosec net/socket.c:1027 [inline] sock_recvmsg net/socket.c:1049 [inline] __sys_recvfrom+0x1f4/0x2e0 net/socket.c:2229 __do_sys_recvfrom net/socket.c:2247 [inline] __se_sys_recvfrom net/socket.c:2243 [inline] __x64_sys_recvfrom+0x78/0x90 net/socket.c:2243 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd value changed: 0x00000000 -> 0x00000016 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 28146 Comm: syz-executor.0 Not tainted 6.6.0-rc3-syzkaller-0005= 5-g9ed22ae6be81 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Goo= gle 09/06/2023 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reported-by: syzbot Reviewed-by: Simon Horman Link: https://lore.kernel.org/r/20231003183455.3410550-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: yenchia.chen Reviewed-by: Carlos Llamas --- net/netlink/af_netlink.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 56ba8a6396ca..216445dd44db 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -352,7 +352,7 @@ static void netlink_overrun(struct sock *sk) if (!(nlk->flags & NETLINK_F_RECV_NO_ENOBUFS)) { if (!test_and_set_bit(NETLINK_S_CONGESTED, &nlk_sk(sk)->state)) { - sk->sk_err =3D ENOBUFS; + WRITE_ONCE(sk->sk_err, ENOBUFS); sk_error_report(sk); } } @@ -1591,7 +1591,7 @@ static int do_one_set_err(struct sock *sk, struct net= link_set_err_data *p) goto out; } =20 - sk->sk_err =3D p->code; + WRITE_ONCE(sk->sk_err, p->code); sk_error_report(sk); out: return ret; @@ -2006,7 +2006,7 @@ static int netlink_recvmsg(struct socket *sock, struc= t msghdr *msg, size_t len, atomic_read(&sk->sk_rmem_alloc) <=3D sk->sk_rcvbuf / 2) { ret =3D netlink_dump(sk); if (ret) { - sk->sk_err =3D -ret; + WRITE_ONCE(sk->sk_err, -ret); sk_error_report(sk); } } @@ -2442,7 +2442,7 @@ void netlink_ack(struct sk_buff *in_skb, struct nlmsg= hdr *nlh, int err, =20 skb =3D nlmsg_new(payload + tlvlen, GFP_KERNEL); if (!skb) { - NETLINK_CB(in_skb).sk->sk_err =3D ENOBUFS; + WRITE_ONCE(NETLINK_CB(in_skb).sk->sk_err, ENOBUFS); sk_error_report(NETLINK_CB(in_skb).sk); return; } --=20 2.18.0