From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx48zNFu6+1Lu8rjrd4Oziw0ZWXtUSJCZ11j6mmbm8lwJQBlXH27+TTwlTvn46mMAOqw+WYmd ARC-Seal: i=1; a=rsa-sha256; t=1523473409; cv=none; d=google.com; s=arc-20160816; b=O85+MDrL2iezN9BmB9fxAvIxux1vYK2fejROML5ybSbTzlzRgNV6PwX7xtKzJXNykd IQ+ZutpDg6crOCsGbayYYjZBvaWYRpsMTn4nDaCQYuUwsvqt8mDALyHVSyQNRRRw847C BSSsRZSPJru9c7iCXJjADQpvTCr2oXUIs6c76kMhlUK/tJfSlEkgowFFgU5CqpbeUi8j DtDJIhc6hqUo2nNKf05JB63XCuCjaIjk0Hcy8BBhLrHRAp8WaXUqlNu1ZZT+63bycAvY VYTfrwLmf3k08bqSuy1Ibj2dHw/pnCAIoL0F64FqzPzdsaewMKtHyQuOQuwEG6ZMpHma rQ8w== 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=0hcMcK1cTiXZq/+ChpV9WgaOLNYwMh/UbqJ9Z6qhe5M=; b=K8aS0X4K3TOUFjG2+KP2Me8YQkMeHA/SLboA4orM2dwwViKPlTjnBNQBKQGq++/pZT Q+PEQU/tqUwg0tCIOYhcE7sKi9xB2DBQUXon+ghV7L0E549j5HPrgsFVSwmAbbqA/pyE HufqnrdK3ii5pIHMsnbYc/LoBGDXfkADjh1tWaBiGWuIS0o0J+zxO1wKqxxLZWyXEgP0 BQCzH1hXwQ1r7vlO3EbYWZqts11G0D59o5Du6/7eJXGh3nZdPa2usewipWJclhc8SzEn HxWZVbLspiEVVCsd1tremwDME3WhPH4a/ejnvW0agvz5TpRpvPKJvgoKHvZB9P8FZ2u+ SqMg== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 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 90.92.61.202 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, Dmitry Vyukov , Marcelo Ricardo Leitner , Cong Wang , Xin Long , "David S. Miller" , Sasha Levin Subject: [PATCH 4.9 237/310] sctp: fix recursive locking warning in sctp_do_peeloff Date: Wed, 11 Apr 2018 20:36:16 +0200 Message-Id: <20180411183632.691959267@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180411183622.305902791@linuxfoundation.org> References: <20180411183622.305902791@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review 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?1597476274816601516?= X-GMAIL-MSGID: =?utf-8?q?1597477653673934400?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long [ Upstream commit 6dfe4b97e08ec3d1a593fdaca099f0ef0a3a19e6 ] Dmitry got the following recursive locking report while running syzkaller fuzzer, the Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:52 print_deadlock_bug kernel/locking/lockdep.c:1729 [inline] check_deadlock kernel/locking/lockdep.c:1773 [inline] validate_chain kernel/locking/lockdep.c:2251 [inline] __lock_acquire+0xef2/0x3430 kernel/locking/lockdep.c:3340 lock_acquire+0x2a1/0x630 kernel/locking/lockdep.c:3755 lock_sock_nested+0xcb/0x120 net/core/sock.c:2536 lock_sock include/net/sock.h:1460 [inline] sctp_close+0xcd/0x9d0 net/sctp/socket.c:1497 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:432 sock_release+0x8d/0x1e0 net/socket.c:597 __sock_create+0x38b/0x870 net/socket.c:1226 sock_create+0x7f/0xa0 net/socket.c:1237 sctp_do_peeloff+0x1a2/0x440 net/sctp/socket.c:4879 sctp_getsockopt_peeloff net/sctp/socket.c:4914 [inline] sctp_getsockopt+0x111a/0x67e0 net/sctp/socket.c:6628 sock_common_getsockopt+0x95/0xd0 net/core/sock.c:2690 SYSC_getsockopt net/socket.c:1817 [inline] SyS_getsockopt+0x240/0x380 net/socket.c:1799 entry_SYSCALL_64_fastpath+0x1f/0xc2 This warning is caused by the lock held by sctp_getsockopt() is on one socket, while the other lock that sctp_close() is getting later is on the newly created (which failed) socket during peeloff operation. This patch is to avoid this warning by use lock_sock with subclass SINGLE_DEPTH_NESTING as Wang Cong and Marcelo's suggestion. Reported-by: Dmitry Vyukov Suggested-by: Marcelo Ricardo Leitner Suggested-by: Cong Wang Signed-off-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- net/sctp/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -1519,7 +1519,7 @@ static void sctp_close(struct sock *sk, pr_debug("%s: sk:%p, timeout:%ld\n", __func__, sk, timeout); - lock_sock(sk); + lock_sock_nested(sk, SINGLE_DEPTH_NESTING); sk->sk_shutdown = SHUTDOWN_MASK; sk->sk_state = SCTP_SS_CLOSING; @@ -1569,7 +1569,7 @@ static void sctp_close(struct sock *sk, * held and that should be grabbed before socket lock. */ spin_lock_bh(&net->sctp.addr_wq_lock); - bh_lock_sock(sk); + bh_lock_sock_nested(sk); /* Hold the sock, since sk_common_release() will put sock_put() * and we have just a little more cleanup.