[CVE-2017-0605][Trusty] tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()

[Po-Hsu Lin]

Cherry-picked and adapted from e09e28671cda63e6308b31798b997639120e2a21, as
the commit(939c7a4) for get_saved_cmdlines() is not there for Precise and
Trusty, apply the fix with the same logic.

From: Amey Telawane <ameyt at codeaurora.org>
Strcpy is inherently not safe, and strlcpy() should be used instead.
__trace_find_cmdline() uses strcpy() because the comms saved must have a
terminating nul character, but it doesn't hurt to add the extra protection
of using strlcpy() instead of strcpy().

Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org

Signed-off-by: Amey Telawane <ameyt at 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 at linaro.org>
[ Updated change log and removed the "- 1" from len parameter ]
Signed-off-by: Steven Rostedt (VMware) <rostedt at goodmis.org>
(cherry picked from commit e09e28671cda63e6308b31798b997639120e2a21)
CVE-2017-0605
Signed-off-by: Po-Hsu Lin <po-hsu.lin at canonical.com>
---
 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 4ac996f..8c92acd 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1498,7 +1498,7 @@ void trace_find_cmdline(int pid, char comm[])
 	arch_spin_lock(&trace_cmdline_lock);
 	map = map_pid_to_cmdline[pid];
 	if (map != NO_CMDLINE_MAP)
-		strcpy(comm, saved_cmdlines[map]);
+		strlcpy(comm, saved_cmdlines[map], TASK_COMM_LEN);
 	else
 		strcpy(comm, "<...>");
 
-- 
1.7.9.5