From: Song Liu <songliubraving@fb.com>
Date: Mon, 9 Apr 2018 18:31:30 +0000
Subject: perf/core: Fix perf_uprobe_init()
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Git-commit: 0eadcc7a7bc03e991d2da1cf88143fb7cc0342c1
Patch-mainline: v4.17-rc1
References: References: FATE#326782, bsc#1115391
Signed-off-by: Tony Jones <tonyj@suse.de>

Similarly to the uprobe PMU fix in perf_kprobe_init(), fix error
handling in perf_uprobe_init() as well.

Reported-by: 范龙飞 <long7573@126.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: e12f03d7031a ("perf/core: Implement the 'perf_kprobe' PMU")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
 kernel/trace/trace_event_perf.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index 94600f1f7efa..c79193e598f5 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -302,6 +302,8 @@ int perf_uprobe_init(struct perf_event *p_event, bool is_retprobe)
 		return -ENOMEM;
 	ret = strncpy_from_user(
 		path, u64_to_user_ptr(p_event->attr.uprobe_path), PATH_MAX);
+	if (ret == PATH_MAX)
+		return -E2BIG;
 	if (ret < 0)
 		goto out;
 	if (path[0] == '\0') {