linuxppc-dev.lists.ozlabs.org archive mirror
 help / color / mirror / Atom feed
From: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
To: peterz@infradead.org, jolsa@redhat.com, mpe@ellerman.id.au,
	maddy@linux.vnet.ibm.com
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>,
	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org,
	acme@kernel.org
Subject: [PATCH 1/2] perf ioctl: Add check for the sample_period value
Date: Sat, 11 May 2019 08:12:16 +0530	[thread overview]
Message-ID: <20190511024217.4013-1-ravi.bangoria@linux.ibm.com> (raw)

Add a check for sample_period value sent from userspace. Negative
value does not make sense. And in powerpc arch code this could cause
a recursive PMI leading to a hang (reported when running perf-fuzzer).

Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
---
 kernel/events/core.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/events/core.c b/kernel/events/core.c
index abbd4b3b96c2..e44c90378940 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5005,6 +5005,9 @@ 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:[~2019-05-11  2:43 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-11  2:42 Ravi Bangoria [this message]
2019-05-11  2:42 ` [PATCH 2/2] powerpc/perf: Fix mmcra corruption by bhrb_filter Ravi Bangoria
2019-05-11  2:47   ` Ravi Bangoria
2019-05-22  5:01   ` Madhavan Srinivasan
2019-05-25  0:54   ` Michael Ellerman
2019-05-13  7:42 ` [PATCH 1/2] perf ioctl: Add check for the sample_period value Peter Zijlstra
2019-05-13  8:56   ` Peter Zijlstra
2019-05-13 10:07     ` Ravi Bangoria
2019-05-28  9:50       ` Michael Ellerman
2019-06-04  4:29         ` [PATCH v2] " Ravi Bangoria
2019-06-17  8:38           ` Ravi Bangoria
2019-06-18 12:28             ` Michael Ellerman

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=20190511024217.4013-1-ravi.bangoria@linux.ibm.com \
    --to=ravi.bangoria@linux.ibm.com \
    --cc=acme@kernel.org \
    --cc=jolsa@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=maddy@linux.vnet.ibm.com \
    --cc=mpe@ellerman.id.au \
    --cc=peterz@infradead.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
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;
as well as URLs for NNTP newsgroup(s).