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* [PATCH 1/2] perf ioctl: Add check for the sample_period value
@ 2019-05-11  2:42 ` Ravi Bangoria
  0 siblings, 0 replies; 24+ messages in thread
From: Ravi Bangoria @ 2019-05-11  2:42 UTC (permalink / raw)
  To: peterz, jolsa, mpe, maddy; +Cc: acme, linux-kernel, linuxppc-dev, Ravi Bangoria

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


^ permalink raw reply related	[flat|nested] 24+ messages in thread

end of thread, other threads:[~2019-06-25  8:19 UTC | newest]

Thread overview: 24+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-11  2:42 [PATCH 1/2] perf ioctl: Add check for the sample_period value Ravi Bangoria
2019-05-11  2:42 ` Ravi Bangoria
2019-05-11  2:42 ` [PATCH 2/2] powerpc/perf: Fix mmcra corruption by bhrb_filter Ravi Bangoria
2019-05-11  2:42   ` Ravi Bangoria
2019-05-11  2:47   ` Ravi Bangoria
2019-05-11  2:47     ` Ravi Bangoria
2019-05-22  5:01   ` Madhavan Srinivasan
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  7:42   ` Peter Zijlstra
2019-05-13  8:56   ` Peter Zijlstra
2019-05-13  8:56     ` Peter Zijlstra
2019-05-13 10:07     ` Ravi Bangoria
2019-05-13 10:07       ` Ravi Bangoria
2019-05-28  9:50       ` Michael Ellerman
2019-05-28  9:50         ` Michael Ellerman
2019-06-04  4:29         ` [PATCH v2] " Ravi Bangoria
2019-06-04  4:29           ` Ravi Bangoria
2019-06-17  8:38           ` Ravi Bangoria
2019-06-17  8:38             ` Ravi Bangoria
2019-06-18 12:28             ` Michael Ellerman
2019-06-18 12:28               ` Michael Ellerman
2019-06-25  8:19           ` [tip:perf/urgent] perf/ioctl: " tip-bot for Ravi Bangoria

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