From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 6B3D07F for ; Sat, 2 Sep 2023 00:28:44 +0000 (UTC) Received: from smtp-fw-80007.amazon.com (smtp-fw-80007.amazon.com [99.78.197.218]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6726FE65 for ; Fri, 1 Sep 2023 17:28:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1693614523; x=1725150523; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=E6Ajmj+CRMUodnV113kmcURCRRcKOZYC2WgwcjByro4=; b=eM36KGRptKxl7dqVq5OsqvPeB7JpaZYjDiaIqfCdMpYRKQN6BCWSae2N C5xT/gLBmAjyUVDB1E/kEGLP6iIWhgfuiP5lQXCWz3N8PuT5u+jPhrop4 pED7nldypQ/0LWRTLoVeSWALcnNkl69Lb1DvDAkJm620fLPLeY4bZ+OxK Y=; X-IronPort-AV: E=Sophos;i="6.02,221,1688428800"; d="scan'208";a="236730479" Received: from pdx4-co-svc-p1-lb2-vlan2.amazon.com (HELO email-inbound-relay-iad-1e-m6i4x-b538c141.us-east-1.amazon.com) ([10.25.36.210]) by smtp-border-fw-80007.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Sep 2023 00:28:40 +0000 Received: from EX19MTAUWB001.ant.amazon.com (iad12-ws-svc-p26-lb9-vlan2.iad.amazon.com [10.40.163.34]) by email-inbound-relay-iad-1e-m6i4x-b538c141.us-east-1.amazon.com (Postfix) with ESMTPS id B42E4A0979; Sat, 2 Sep 2023 00:28:37 +0000 (UTC) Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWB001.ant.amazon.com (10.250.64.248) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.37; Sat, 2 Sep 2023 00:28:36 +0000 Received: from 88665a182662.ant.amazon.com (10.187.170.14) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.37; Sat, 2 Sep 2023 00:28:34 +0000 From: Kuniyuki Iwashima To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni CC: Kuniyuki Iwashima , Kuniyuki Iwashima , , syzkaller Subject: [PATCH v1 net 3/4] af_unix: Fix data-races around sk->sk_shutdown. Date: Fri, 1 Sep 2023 17:27:07 -0700 Message-ID: <20230902002708.91816-4-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20230902002708.91816-1-kuniyu@amazon.com> References: <20230902002708.91816-1-kuniyu@amazon.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.187.170.14] X-ClientProxiedBy: EX19D042UWA002.ant.amazon.com (10.13.139.17) To EX19D004ANA001.ant.amazon.com (10.37.240.138) Precedence: Bulk X-Spam-Status: No, score=-1.7 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,T_SPF_PERMERROR autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net sk->sk_shutdown is changed under unix_state_lock(sk), but unix_dgram_sendmsg() calls two functions to read sk_shutdown locklessly. sock_alloc_send_pskb `- sock_wait_for_wmem Let's use READ_ONCE() there. Note that the writer side was marked by commit e1d09c2c2f57 ("af_unix: Fix data races around sk->sk_shutdown."). BUG: KCSAN: data-race in sock_alloc_send_pskb / unix_release_sock write (marked) to 0xffff8880069af12c of 1 bytes by task 1 on cpu 1: unix_release_sock+0x75c/0x910 net/unix/af_unix.c:631 unix_release+0x59/0x80 net/unix/af_unix.c:1053 __sock_release+0x7d/0x170 net/socket.c:654 sock_close+0x19/0x30 net/socket.c:1386 __fput+0x2a3/0x680 fs/file_table.c:384 ____fput+0x15/0x20 fs/file_table.c:412 task_work_run+0x116/0x1a0 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x174/0x180 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1a/0x30 kernel/entry/common.c:297 do_syscall_64+0x4b/0x90 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 read to 0xffff8880069af12c of 1 bytes by task 28650 on cpu 0: sock_alloc_send_pskb+0xd2/0x620 net/core/sock.c:2767 unix_dgram_sendmsg+0x2f8/0x14f0 net/unix/af_unix.c:1944 unix_seqpacket_sendmsg net/unix/af_unix.c:2308 [inline] unix_seqpacket_sendmsg+0xba/0x130 net/unix/af_unix.c:2292 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0x148/0x160 net/socket.c:748 ____sys_sendmsg+0x4e4/0x610 net/socket.c:2494 ___sys_sendmsg+0xc6/0x140 net/socket.c:2548 __sys_sendmsg+0x94/0x140 net/socket.c:2577 __do_sys_sendmsg net/socket.c:2586 [inline] __se_sys_sendmsg net/socket.c:2584 [inline] __x64_sys_sendmsg+0x45/0x50 net/socket.c:2584 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x6e/0xd8 value changed: 0x00 -> 0x03 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 28650 Comm: systemd-coredum Not tainted 6.4.0-11989-g6843306689af #6 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzkaller Signed-off-by: Kuniyuki Iwashima --- net/core/sock.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index d3c7b53368d2..e3da7eae9338 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2747,7 +2747,7 @@ static long sock_wait_for_wmem(struct sock *sk, long timeo) prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE); if (refcount_read(&sk->sk_wmem_alloc) < READ_ONCE(sk->sk_sndbuf)) break; - if (sk->sk_shutdown & SEND_SHUTDOWN) + if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) break; if (sk->sk_err) break; @@ -2777,7 +2777,7 @@ struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, goto failure; err = -EPIPE; - if (sk->sk_shutdown & SEND_SHUTDOWN) + if (READ_ONCE(sk->sk_shutdown) & SEND_SHUTDOWN) goto failure; if (sk_wmem_alloc_get(sk) < READ_ONCE(sk->sk_sndbuf)) -- 2.30.2