From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuwmJqW07Ab+ucgVkx2HsGiN6aI8lmaGchOgKdmAldhBgg2R6XdsFtT6nJWsCw43xLU2naG ARC-Seal: i=1; a=rsa-sha256; t=1519676765; cv=none; d=google.com; s=arc-20160816; b=CJEABGeQ34mpzNM/cRa4sQY2tlTeWqlRJ2SGzwM1+MCcBro8lUWmN3a1m/xhwkyCoK qPVI6OBG4sHb5CVRDWq8b63uh4jvP4VjniC2CRXbKY/7lPvDKAYedFxXsVyNlKRkXVp5 zXOxws4jz0P3IllGVV88tFXtBkRuDAOoPW06X3ZRKSMqSudcStmlgmuppuDQx5BWPiCW Egpl5lVsmzUfiO6kbGp/XwbBZtuWvwptIkqxOGupVPSbnc76cLsKqDfcRXKWHG/wfRSa 8pKoK4sXKloBt81X+GWPI5WHyc+rnfbnNA53hHOeKGCNFEpEWnSXrZjEhHtHAJz4TMrT tcQg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=NCg12nAUEKT+YolnLil0OVHpUV7yKnHBm/VdSqxMgmM=; b=09/iCFGHA7D2WaQzKxgk5z9pWmDFcQQ9ezaGOQsLdnkWCNspqYffd5RdkJyVZLkuw7 NQ9cdeTIG8AsBTW55PlTX8ycXSyo1b91i62i1m9cK1vxPzvZSLTi7j2lPN5+NFYqO4om ceBQ/+7eCe1gFrwGyRznTxbIwSSfC0keA/6u9ICqUdnJriY4X0xcVZiT+edjZCplePgs GbnzifYrEhPuukn0BEHjl1PvJJ4lg+ej4fW72Lxwh2xnIDgNjuLXBPgMyF4DGqGBMWTH KI8OJ5kkuZ1WppsInophEf2wm9VtUZ1yo0058unf7zH2cv0jPpVUTktzPo7OQHmY+xop 10gA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 83.175.124.243 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 83.175.124.243 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Xin Long , syzbot+ddde1c7b7ff7442d7f2d@syzkaller.appspotmail.com, Florian Westphal , Paolo Abeni , Pablo Neira Ayuso , Krzysztof Piotr Oledzki Subject: [PATCH 4.15 01/64] netfilter: drop outermost socket lock in getsockopt() Date: Mon, 26 Feb 2018 21:21:38 +0100 Message-Id: <20180226202153.512855240@linuxfoundation.org> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180226202153.453363333@linuxfoundation.org> References: <20180226202153.453363333@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1593495940069905483?= X-GMAIL-MSGID: =?utf-8?q?1593496584091631582?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit 01ea306f2ac2baff98d472da719193e738759d93 upstream. The Syzbot reported a possible deadlock in the netfilter area caused by rtnl lock, xt lock and socket lock being acquired with a different order on different code paths, leading to the following backtrace: Reviewed-by: Xin Long ====================================================== WARNING: possible circular locking dependency detected 4.15.0+ #301 Not tainted ------------------------------------------------------ syzkaller233489/4179 is trying to acquire lock: (rtnl_mutex){+.+.}, at: [<0000000048e996fd>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:74 but task is already holding lock: (&xt[i].mutex){+.+.}, at: [<00000000328553a2>] xt_find_table_lock+0x3e/0x3e0 net/netfilter/x_tables.c:1041 which lock already depends on the new lock. === Since commit 3f34cfae1230 ("netfilter: on sockopt() acquire sock lock only in the required scope"), we already acquire the socket lock in the innermost scope, where needed. In such commit I forgot to remove the outer-most socket lock from the getsockopt() path, this commit addresses the issues dropping it now. v1 -> v2: fix bad subj, added relavant 'fixes' tag Fixes: 22265a5c3c10 ("netfilter: xt_TEE: resolve oif using netdevice notifiers") Fixes: 202f59afd441 ("netfilter: ipt_CLUSTERIP: do not hold dev") Fixes: 3f34cfae1230 ("netfilter: on sockopt() acquire sock lock only in the required scope") Reported-by: syzbot+ddde1c7b7ff7442d7f2d@syzkaller.appspotmail.com Suggested-by: Florian Westphal Signed-off-by: Paolo Abeni Signed-off-by: Pablo Neira Ayuso Tested-by: Krzysztof Piotr Oledzki Signed-off-by: Greg Kroah-Hartman --- net/ipv4/ip_sockglue.c | 7 +------ net/ipv6/ipv6_sockglue.c | 10 ++-------- 2 files changed, 3 insertions(+), 14 deletions(-) --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -1563,10 +1563,7 @@ int ip_getsockopt(struct sock *sk, int l if (get_user(len, optlen)) return -EFAULT; - lock_sock(sk); - err = nf_getsockopt(sk, PF_INET, optname, optval, - &len); - release_sock(sk); + err = nf_getsockopt(sk, PF_INET, optname, optval, &len); if (err >= 0) err = put_user(len, optlen); return err; @@ -1598,9 +1595,7 @@ int compat_ip_getsockopt(struct sock *sk if (get_user(len, optlen)) return -EFAULT; - lock_sock(sk); err = compat_nf_getsockopt(sk, PF_INET, optname, optval, &len); - release_sock(sk); if (err >= 0) err = put_user(len, optlen); return err; --- a/net/ipv6/ipv6_sockglue.c +++ b/net/ipv6/ipv6_sockglue.c @@ -1367,10 +1367,7 @@ int ipv6_getsockopt(struct sock *sk, int if (get_user(len, optlen)) return -EFAULT; - lock_sock(sk); - err = nf_getsockopt(sk, PF_INET6, optname, optval, - &len); - release_sock(sk); + err = nf_getsockopt(sk, PF_INET6, optname, optval, &len); if (err >= 0) err = put_user(len, optlen); } @@ -1409,10 +1406,7 @@ int compat_ipv6_getsockopt(struct sock * if (get_user(len, optlen)) return -EFAULT; - lock_sock(sk); - err = compat_nf_getsockopt(sk, PF_INET6, - optname, optval, &len); - release_sock(sk); + err = compat_nf_getsockopt(sk, PF_INET6, optname, optval, &len); if (err >= 0) err = put_user(len, optlen); }