* [PATCH 4.19 447/639] perf/ioctl: Add check for the sample_period value
[not found] <20200124093047.008739095@linuxfoundation.org>
@ 2020-01-24 9:30 ` Greg Kroah-Hartman
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From: Greg Kroah-Hartman @ 2020-01-24 9:30 UTC (permalink / raw)
To: linux-kernel
Cc: Sasha Levin, Ravi Bangoria, maddy, acme, Vince Weaver,
Peter Zijlstra (Intel), Greg Kroah-Hartman, Linus Torvalds,
linuxppc-dev, stable, Arnaldo Carvalho de Melo,
Alexander Shishkin, Stephane Eranian, Thomas Gleixner, Jiri Olsa,
Ingo Molnar
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 751888cbed5c0..16af86ab24c42 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -5012,6 +5012,9 @@ 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
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