From 01e71c218219fe40c620a53b2d37beafd95c4e14 Mon Sep 17 00:00:00 2001
From: Jiri Olsa <jolsa@kernel.org>
Date: Sun, 15 Apr 2018 11:23:50 +0200
Subject: [PATCH] perf: Return proper values for user stack errors
commit 78b562fbfa2cf0a9fcb23c3154756b690f4905c1 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: 60e2364e60e8 ("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>
---
kernel/events/core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index e9b0beca830f..cb8274d7824f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -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)