[PATCH] tracing: Resolve stack corruption due to string copy

From: Amit Pundir <amit.pundir@linaro.org>
To: Steven Rostedt <rostedt@goodmis.org>, Ingo Molnar <mingo@redhat.com>
Cc: Greg KH <gregkh@linuxfoundation.org>,
	lkml <linux-kernel@vger.kernel.org>,
	Amey Telawane <ameyt@codeaurora.org>,
	stable@vger.kernel.org
Subject: [PATCH] tracing: Resolve stack corruption due to string copy
Date: Wed,  3 May 2017 15:41:14 +0530	[thread overview]
Message-ID: <1493806274-13936-1-git-send-email-amit.pundir@linaro.org> (raw)

From: Amey Telawane <ameyt@codeaurora.org>

Strcpy has no limit on string being copied which causes
stack corruption leading to kernel panic. Use strlcpy to
resolve the issue by providing length of string to be copied.

Cc: stable@vger.kernel.org
Signed-off-by: Amey Telawane <ameyt@codeaurora.org>
[AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10
https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477]
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
---
This patch featured in Android Security Bulletin for May 2017,
https://source.android.com/security/bulletin/2017-05-01#eop-in-kernel-trace-subsystem,
but it is not upstreamed yet and I couldn't find any previous
upstream submission as well.

 kernel/trace/trace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index bd8fb5cfda4d..b227e141e1f1 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1976,7 +1976,7 @@ static void __trace_find_cmdline(int pid, char comm[])
 
 	map = savedcmd->map_pid_to_cmdline[pid];
 	if (map != NO_CMDLINE_MAP)
-		strcpy(comm, get_saved_cmdlines(map));
+		strlcpy(comm, get_saved_cmdlines(map), TASK_COMM_LEN - 1);
 	else
 		strcpy(comm, "<...>");
 }
-- 
2.7.4
