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=-16.6 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 1A0C0C10F07 for ; Wed, 20 Feb 2019 16:54:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC2FC218D8 for ; Wed, 20 Feb 2019 16:54:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vGcXQ8Kp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726924AbfBTQyt (ORCPT ); Wed, 20 Feb 2019 11:54:49 -0500 Received: from mail-qt1-f201.google.com ([209.85.160.201]:53775 "EHLO mail-qt1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725885AbfBTQys (ORCPT ); Wed, 20 Feb 2019 11:54:48 -0500 Received: by mail-qt1-f201.google.com with SMTP id k37so23793670qtb.20 for ; Wed, 20 Feb 2019 08:54:48 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=pkDVCnN2cgim62Luscb6DEnMU5ESMPb2u/eLYbyrXCg=; b=vGcXQ8Kpewn3WZblPHZlkB+6dH40Vcy4tfDV3MoaxWJRAsVd+sDJdx0HFDStW4FLOJ mYgBKp0U+DiWX9k0ge7cpZeFhjRfwYMM1Smtc4RpsRhl6ySWDqJLIwQyoYcP4SMc7pKK LDiysPwES5qtYcmobPY9QmpHDy+WPY7JGwI/94bnuxisW7qXA1unov08eajDlWEYlucJ 8KyjVXYeWZTLRaw4UMqZ2G1+TmHp7O4lei+j+VlU+/tr68Q9UTVP1dB5bsscU9o78Nuk gwy8w5leVJ8M0x7B9R6VpVz0iJfPDO3gyhwTCOrWvdvxm6lmRgHvUVOe3OBXwQz8qSSF k1RQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=pkDVCnN2cgim62Luscb6DEnMU5ESMPb2u/eLYbyrXCg=; b=PW06moCrLRMwYg2J3lB8SC7NUivxOTINhejoZ1DdKXNlj6Rm9Eo3KWtSjBFB46LAhB f3HRpQW24rmaf2bCQIqivm5HrHHAzGcSrFUKeo+2uhYHFbyTMDLlgSD86LHKXTM1XfYk yHbLW6VKxV83gnUGLBRzox5Ivsc0S/eL3RVvQ+nENKAKG0bXixxE92/wy2T7nhcevhAX tnU0n+KbR08cOSDhCpm/UIR80b0BbinDtIGapcozS3U06fdth/fEikNZoE7bi8aBGNFZ BxbqMRupuoBLmlgYD9HTQRon77LyuFKeSNwguVPcdPIdbRw8Gs5ErnW2gr2DXJksG6hl qHRA== X-Gm-Message-State: AHQUAuZPLUuZFUpLMQsoXl1+NF/+rqdvjLbO5LwGtruK5g2ccrxPyq0u AEUqO7iHWGqftzAdGoQQIQC/2g4Q0A== X-Google-Smtp-Source: AHgI3IaBlAsWN6zUr1YNDIlQPjXmXAQtC+r3TgDLHbReNCZkGJgXrcRyv7zcde5NUwVX2Gz2c+77kEul9w== X-Received: by 2002:ae9:f405:: with SMTP id y5mr20427650qkl.49.1550681687633; Wed, 20 Feb 2019 08:54:47 -0800 (PST) Date: Wed, 20 Feb 2019 17:54:43 +0100 Message-Id: <20190220165443.152385-1-jannh@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.21.0.rc0.258.g878e2cd30e-goog Subject: [PATCH v2] perf/core: use strndup_user() instead of buggy open-coded version From: Jann Horn To: Ingo Molnar , Steven Rostedt , jannh@google.com Cc: linux-kernel@vger.kernel.org, Song Liu , Masami Hiramatsu Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The first version of this method was missing the check for `ret == PATH_MAX`; then such a check was added, but it didn't call kfree() on error, so there was still a small memory leak in the error case. Fix it by using strndup_user() instead of open-coding it. Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()") Signed-off-by: Jann Horn --- v2: - be compatible with existing error codes (Masami Hiramatsu) kernel/trace/trace_event_perf.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c index 76217bbef815..4629a6104474 100644 --- a/kernel/trace/trace_event_perf.c +++ b/kernel/trace/trace_event_perf.c @@ -299,15 +299,13 @@ int perf_uprobe_init(struct perf_event *p_event, if (!p_event->attr.uprobe_path) return -EINVAL; - path = kzalloc(PATH_MAX, GFP_KERNEL); - if (!path) - return -ENOMEM; - ret = strncpy_from_user( - path, u64_to_user_ptr(p_event->attr.uprobe_path), PATH_MAX); - if (ret == PATH_MAX) - return -E2BIG; - if (ret < 0) - goto out; + + path = strndup_user(u64_to_user_ptr(p_event->attr.uprobe_path), + PATH_MAX); + if (IS_ERR(path)) { + ret = PTR_ERR(path); + return (ret == -EINVAL) ? -E2BIG : ret; + } if (path[0] == '\0') { ret = -EINVAL; goto out; -- 2.21.0.rc0.258.g878e2cd30e-goog