From patchwork Mon Apr 14 16:02:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masami Ichikawa X-Patchwork-Id: 338995 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id E15CC14008C for ; Tue, 15 Apr 2014 02:03:30 +1000 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754663AbaDNQC6 (ORCPT ); Mon, 14 Apr 2014 12:02:58 -0400 Received: from mail-pb0-f48.google.com ([209.85.160.48]:44539 "EHLO mail-pb0-f48.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754441AbaDNQC4 (ORCPT ); Mon, 14 Apr 2014 12:02:56 -0400 Received: by mail-pb0-f48.google.com with SMTP id md12so8361983pbc.7 for ; Mon, 14 Apr 2014 09:02:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id; bh=0gDdu/c/S2QkgO37fxE+VehBJ5cmu1dZ+2Si98YZP1A=; b=0BIvQ6+PYuVBmiJjdmjZaX1G6Xe6WaPJqdk6xtWTgKLAiMew9z7uscnq2FomEFPDGc oXZYEBhzw8g9iq+oAiqtSEG1r1y+tKRyk0kP/wVtCxyh4Nq1zEg3//p9myACDwAT9U8f YynrQoeTXIV/txg3umXzLrtC/Lwvft5/ApO7txjh+3AY0s3oVLAC9qwUx7K4PbtPqdga Ao58UoMg95PvR7o1QVn2XUIhAHlceBnw4gDo7lwSoCiG1gX/N4+QEcyGNXLReHzb912C kXQI30Uob4tKkBUy4j2ybMLPGJk8uCbQHhSP5zl2oMbYabjzmx0bVDBFmvqx0/p/m43r VfTA== X-Received: by 10.67.1.39 with SMTP id bd7mr45300481pad.15.1397491375834; Mon, 14 Apr 2014 09:02:55 -0700 (PDT) Received: from localhost.localdomain (FL1-119-242-45-61.tky.mesh.ad.jp. [119.242.45.61]) by mx.google.com with ESMTPSA id pr4sm34601954pbb.53.2014.04.14.09.02.53 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 14 Apr 2014 09:02:55 -0700 (PDT) From: Masami Ichikawa To: keescook@chromium.org, davem@davemloft.net, josh@joshtriplett.org, eparis@redhat.com, rashika.kheria@gmail.com, ast@plumgrid.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org Cc: masami256@gmail.com Subject: [PATCH] seccomp: Release fp pointer when leaving from seccomp_attach_filter(). Date: Tue, 15 Apr 2014 01:02:13 +0900 Message-Id: <1397491333-13746-1-git-send-email-masami256@gmail.com> X-Mailer: git-send-email 1.9.2 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org kmemleak reported some memory leak as below. unreferenced object 0xffff8800d6ea4000 (size 512): comm "sshd", pid 278, jiffies 4294898315 (age 46.653s) hex dump (first 32 bytes): 21 00 00 00 04 00 00 00 15 00 01 00 3e 00 00 c0 !...........>... 06 00 00 00 00 00 00 00 21 00 00 00 00 00 00 00 ........!....... backtrace: [] kmemleak_alloc+0x4e/0xb0 [] __kmalloc+0x280/0x320 [] prctl_set_seccomp+0x11e/0x3b0 [] SyS_prctl+0x3bb/0x4a0 [] system_call_fastpath+0x1a/0x1f [] 0xffffffffffffffff This memory leak happend in seccomp_attach_filter(). The fp pointer was allocated via kzalloc so that it needs to realase memory when leaving from function. This patch changed two things. One is set -ENOMEM to ret, if fp is unable to get memory. The other is removes "return 0" statement, and frees fp pointer before leaving. Signed-off-by: Masami Ichikawa --- kernel/seccomp.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/kernel/seccomp.c b/kernel/seccomp.c index d8d046c..a9ce7a9 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -259,8 +259,10 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) filter = kzalloc(sizeof(struct seccomp_filter) + sizeof(struct sock_filter_int) * new_len, GFP_KERNEL|__GFP_NOWARN); - if (!filter) + if (!filter) { + ret = -ENOMEM; goto free_prog; + } ret = sk_convert_filter(fp, fprog->len, filter->insnsi, &new_len); if (ret) @@ -275,10 +277,10 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) */ filter->prev = current->seccomp.filter; current->seccomp.filter = filter; - return 0; free_filter: - kfree(filter); + if (ret) + kfree(filter); free_prog: kfree(fp); return ret;