From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 550D1C43460 for ; Thu, 1 Apr 2021 09:10:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2756C610D2 for ; Thu, 1 Apr 2021 09:10:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233781AbhDAJKC (ORCPT ); Thu, 1 Apr 2021 05:10:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33608 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233732AbhDAJJw (ORCPT ); Thu, 1 Apr 2021 05:09:52 -0400 Received: from mail-pj1-x1031.google.com (mail-pj1-x1031.google.com [IPv6:2607:f8b0:4864:20::1031]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BCF56C0613E6 for ; Thu, 1 Apr 2021 02:09:52 -0700 (PDT) Received: by mail-pj1-x1031.google.com with SMTP id nh23-20020a17090b3657b02900c0d5e235a8so703968pjb.0 for ; Thu, 01 Apr 2021 02:09:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20150623.gappssmtp.com; s=20150623; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=+IsVjISMkpZP5tT2zT9xXS3PV75jGVHq8NuXz4FV7zU=; b=Tcop26gJmkd/1TqpULLeDQ2otNmc6j+/VT4iMfeBNgjEfZGjZLKKY1ePPRrQIP3viG Esvxv2FAIs51D5A/9yYudr9r1G81x0btHrw8kyZ99swJEdFy/+ABh7aE6ecvN3vRhOvv 7MvjzbztD7AU/8KGWNLBmKKRQpzfQTVyEelQwkJfB8O/1nqvRkIGHQBI7rN8xgI7pNb2 GduPhZ3AeBM5D7ClCe70GmFCitB8rR7szjOOuVl1AlLoToz0FbP7n/NAhunhM4nu8X3I dnGXfOsxHa5nL7iMivXJJIuny92B72ytUP1lCBRLB5bv0EwmDE/euDet7RVGVBKcRaeR /3gQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=+IsVjISMkpZP5tT2zT9xXS3PV75jGVHq8NuXz4FV7zU=; b=c9r/wqHl6KoJ5CtrgRZaRELjZQg1vJnqONYmIfYyhbqsvnVxxkKODoXAhXsGyIJ6nl /gko43GgeBZ8i9h+cXRelhmD0UVbbRXsn1DGxx8TVlD9pmtVHt0FxKS+P7yLYKH4B95n oy7GiiEe8wsJzBUaZTUsNGdBDmya+qa1B42Ty+McRTdisJ06EIIuJbjwHYims1QsE0bz fADNw7A2oMFuXcuZmD8slP36X12+jweX0Qy0OlfCgAAtFMuhS2ziGOTkpP1E/G6s9w1E sl0PoKCtK0S8GX2BAALSlfFEGwX80rDKStutsHX5QHcPSqJu5KMnOlurnRlWr1y4VaFO Dtsg== X-Gm-Message-State: AOAM533nHgyskED/g500M3ikdcdlCnYOVIwabpltad0KNjIJbGoP2s5V iGKXCN9OOSLlp1rSwAKfaYLx X-Google-Smtp-Source: ABdhPJzD1ZPSRBjIXRewRBPdRngJTQcG7U1Ly+YzsKw0o4Hb/fRlfsUZ6aEHLdqdggJrzuxMD5kH5A== X-Received: by 2002:a17:902:c945:b029:e7:1ec4:4315 with SMTP id i5-20020a170902c945b02900e71ec44315mr6937613pla.51.1617268192395; Thu, 01 Apr 2021 02:09:52 -0700 (PDT) Received: from localhost ([139.177.225.243]) by smtp.gmail.com with ESMTPSA id f21sm4303758pfe.6.2021.04.01.02.09.51 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Apr 2021 02:09:52 -0700 (PDT) From: Xie Yongji To: christian.brauner@ubuntu.com, hch@infradead.org, gregkh@linuxfoundation.org, arve@android.com, tkjos@android.com, maco@android.com, joel@joelfernandes.org, hridya@google.com, surenb@google.com, viro@zeniv.linux.org.uk, sargun@sargun.me, keescook@chromium.org, jasowang@redhat.com Cc: devel@driverdev.osuosl.org, linux-fsdevel@vger.kernel.org Subject: [PATCH 2/2] binder: Use receive_fd() to receive file from another process Date: Thu, 1 Apr 2021 17:09:32 +0800 Message-Id: <20210401090932.121-3-xieyongji@bytedance.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210401090932.121-1-xieyongji@bytedance.com> References: <20210401090932.121-1-xieyongji@bytedance.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Use receive_fd() to receive file from another process instead of combination of get_unused_fd_flags() and fd_install(). This simplifies the logic and also makes sure we don't miss any security stuff. Signed-off-by: Xie Yongji --- drivers/android/binder.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/android/binder.c b/drivers/android/binder.c index c119736ca56a..080bcab7d632 100644 --- a/drivers/android/binder.c +++ b/drivers/android/binder.c @@ -3728,7 +3728,7 @@ static int binder_apply_fd_fixups(struct binder_proc *proc, int ret = 0; list_for_each_entry(fixup, &t->fd_fixups, fixup_entry) { - int fd = get_unused_fd_flags(O_CLOEXEC); + int fd = receive_fd(fixup->file, O_CLOEXEC); if (fd < 0) { binder_debug(BINDER_DEBUG_TRANSACTION, @@ -3741,7 +3741,7 @@ static int binder_apply_fd_fixups(struct binder_proc *proc, "fd fixup txn %d fd %d\n", t->debug_id, fd); trace_binder_transaction_fd_recv(t, fd, fixup->offset); - fd_install(fd, fixup->file); + fput(fixup->file); fixup->file = NULL; if (binder_alloc_copy_to_buffer(&proc->alloc, t->buffer, fixup->offset, &fd, -- 2.11.0