Commit 01e71c21 authored Apr 15, 2018 by Jiri Olsa Committed by Greg Kroah-Hartman Apr 26, 2018

perf: Return proper values for user stack errors



commit 78b562fb upstream.

Return immediately when we find issue in the user stack checks. The
error value could get overwritten by following check for
PERF_SAMPLE_REGS_INTR.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: syzkaller-bugs@googlegroups.com
Cc: x86@kernel.org
Fixes: 60e2364e ("perf: Add ability to sample machine state on interrupt")
Link: http://lkml.kernel.org/r/20180415092352.12403-1-jolsa@kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 66038084

kernel/events/core.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -9750,9 +9750,9 @@ static int perf_copy_attr(struct perf_event_attr __user *uattr,
		* __u16 sample size limit.
		*/
		if (attr->sample_stack_user >= USHRT_MAX)
		ret = -EINVAL;
		return -EINVAL;
		else if (!IS_ALIGNED(attr->sample_stack_user, sizeof(u64)))
		ret = -EINVAL;
		return -EINVAL;
		}

		if (attr->sample_type & PERF_SAMPLE_REGS_INTR)