From patchwork Wed Mar 30 23:53:13 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 603804 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id 3qb4KS4Yrkz9sXQ; Thu, 31 Mar 2016 10:55:56 +1100 (AEDT) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1alPxn-0006qD-Sc; Wed, 30 Mar 2016 23:55:51 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.76) (envelope-from ) id 1alPvJ-0005Jj-NR for kernel-team@lists.ubuntu.com; Wed, 30 Mar 2016 23:53:17 +0000 Received: from 1.general.kamal.us.vpn ([10.172.68.52] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1alPvJ-0007qX-86; Wed, 30 Mar 2016 23:53:17 +0000 Received: from kamal by fourier with local (Exim 4.86_2) (envelope-from ) id 1alPvG-0001RO-In; Wed, 30 Mar 2016 16:53:14 -0700 From: Kamal Mostafa To: "Steven Rostedt (Red Hat)" Subject: [4.2.y-ckt stable] Patch "tracing: Fix crash from reading trace_pipe with sendfile" has been added to the 4.2.y-ckt tree Date: Wed, 30 Mar 2016 16:53:13 -0700 Message-Id: <1459381993-5503-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 X-Extended-Stable: 4.2 Cc: Rabin Vincent , Kamal Mostafa , kernel-team@lists.ubuntu.com X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled tracing: Fix crash from reading trace_pipe with sendfile to the linux-4.2.y-queue branch of the 4.2.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-4.2.y-queue This patch is scheduled to be released in version 4.2.8-ckt7. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 4.2.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ---8<------------------------------------------------------------ From 49b5c3487857a4d94ab7ea0ccfa2610104126466 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Fri, 18 Mar 2016 15:46:48 -0400 Subject: tracing: Fix crash from reading trace_pipe with sendfile commit a29054d9478d0435ab01b7544da4f674ab13f533 upstream. If tracing contains data and the trace_pipe file is read with sendfile(), then it can trigger a NULL pointer dereference and various BUG_ON within the VM code. There's a patch to fix this in the splice_to_pipe() code, but it's also a good idea to not let that happen from trace_pipe either. Link: http://lkml.kernel.org/r/1457641146-9068-1-git-send-email-rabin@rab.in Reported-by: Rabin Vincent Signed-off-by: Steven Rostedt Signed-off-by: Kamal Mostafa --- kernel/trace/trace.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) -- 2.7.4 diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 126f8f6..8693c83 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4917,7 +4917,10 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, spd.nr_pages = i; - ret = splice_to_pipe(pipe, &spd); + if (i) + ret = splice_to_pipe(pipe, &spd); + else + ret = 0; out: splice_shrink_spd(&spd); return ret;