public inbox for linuxppc-dev@ozlabs.org 
 help / color / mirror / Atom feed
From: Greg Kroah-Hartman <gregkh@linuxfoundation•org>
To: linux-kernel@vger•kernel.org
Cc: Sasha Levin <sashal@kernel•org>,
	Ravi Bangoria <ravi.bangoria@linux•ibm.com>,
	maddy@linux•vnet.ibm.com, acme@kernel•org,
	Vince Weaver <vincent.weaver@maine•edu>,
	"Peter Zijlstra \(Intel\)" <peterz@infradead•org>,
	Greg Kroah-Hartman <gregkh@linuxfoundation•org>,
	Linus Torvalds <torvalds@linux-foundation•org>,
	linuxppc-dev@lists•ozlabs.org, stable@vger•kernel.org,
	Arnaldo Carvalho de Melo <acme@redhat•com>,
	Alexander Shishkin <alexander.shishkin@linux•intel.com>,
	Stephane Eranian <eranian@google•com>,
	Thomas Gleixner <tglx@linutronix•de>,
	Jiri Olsa <jolsa@redhat•com>, Ingo Molnar <mingo@kernel•org>
Subject: [PATCH 4.14 243/343] perf/ioctl: Add check for the sample_period value
Date: Fri, 24 Jan 2020 10:31:01 +0100	[thread overview]
Message-ID: <20200124092952.083914150@linuxfoundation.org> (raw)
In-Reply-To: <20200124092919.490687572@linuxfoundation.org>

From: Ravi Bangoria <ravi.bangoria@linux•ibm.com>

[ Upstream commit 913a90bc5a3a06b1f04c337320e9aeee2328dd77 ]

perf_event_open() limits the sample_period to 63 bits. See:

  0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits")

Make ioctl() consistent with it.

Also on PowerPC, negative sample_period could cause a recursive
PMIs leading to a hang (reported when running perf-fuzzer).

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux•ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead•org>
Cc: Alexander Shishkin <alexander.shishkin@linux•intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat•com>
Cc: Jiri Olsa <jolsa@redhat•com>
Cc: Linus Torvalds <torvalds@linux-foundation•org>
Cc: Peter Zijlstra <peterz@infradead•org>
Cc: Stephane Eranian <eranian@google•com>
Cc: Thomas Gleixner <tglx@linutronix•de>
Cc: Vince Weaver <vincent.weaver@maine•edu>
Cc: acme@kernel•org
Cc: linuxppc-dev@lists•ozlabs.org
Cc: maddy@linux•vnet.ibm.com
Cc: mpe@ellerman•id.au
Fixes: 0819b2e30ccb ("perf: Limit perf_event_attr::sample_period to 63 bits")
Link: https://lkml.kernel.org/r/20190604042953.914-1-ravi.bangoria@linux.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel•org>
Signed-off-by: Sasha Levin <sashal@kernel•org>
---
 kernel/events/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index ea4f3f7a0c6f3..2ac73b4cb8a93 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4762,6 +4762,9 @@ static int perf_event_period(struct perf_event *event, u64 __user *arg)
 	if (perf_event_check_period(event, value))
 		return -EINVAL;
 
+	if (!event->attr.freq && (value & (1ULL << 63)))
+		return -EINVAL;
+
 	event_function_call(event, __perf_event_period, &value);
 
 	return 0;
-- 
2.20.1




           reply	other threads:[~2020-01-24 10:06 UTC|newest]

Thread overview: expand[flat|nested]  mbox.gz  Atom feed
 [parent not found: <20200124092919.490687572@linuxfoundation.org>]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200124092952.083914150@linuxfoundation.org \
    --to=gregkh@linuxfoundation$(echo .)org \
    --cc=acme@kernel$(echo .)org \
    --cc=acme@redhat$(echo .)com \
    --cc=alexander.shishkin@linux$(echo .)intel.com \
    --cc=eranian@google$(echo .)com \
    --cc=jolsa@redhat$(echo .)com \
    --cc=linux-kernel@vger$(echo .)kernel.org \
    --cc=linuxppc-dev@lists$(echo .)ozlabs.org \
    --cc=maddy@linux$(echo .)vnet.ibm.com \
    --cc=mingo@kernel$(echo .)org \
    --cc=peterz@infradead$(echo .)org \
    --cc=ravi.bangoria@linux$(echo .)ibm.com \
    --cc=sashal@kernel$(echo .)org \
    --cc=stable@vger$(echo .)kernel.org \
    --cc=tglx@linutronix$(echo .)de \
    --cc=torvalds@linux-foundation$(echo .)org \
    --cc=vincent.weaver@maine$(echo .)edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox