Commit 820b75f6 authored Nov 19, 2014 by Steven Rostedt (Red Hat) Committed by Steven Rostedt Nov 19, 2014

tracing: Add paranoid size check in trace_printk_seq()

To be really paranoid about writing out of bound data in
trace_printk_seq(), add another check of len compared to size.

Link: http://lkml.kernel.org/r/20141119144004.GB2332@dhcp128.suse.cz



Suggested-by: Petr Mladek <pmladek@suse.cz>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent 5ac48378

kernel/trace/trace.c

+8 −0

Original line number	Diff line number	Diff line
		@@ -6656,6 +6656,14 @@ trace_printk_seq(struct trace_seq *s)
		if (s->seq.len >= TRACE_MAX_PRINT)
		s->seq.len = TRACE_MAX_PRINT;

		/*
		* More paranoid code. Although the buffer size is set to
		* PAGE_SIZE, and TRACE_MAX_PRINT is 1000, this is just
		* an extra layer of protection.
		*/
		if (WARN_ON_ONCE(s->seq.len >= s->seq.size))
		s->seq.len = s->seq.size - 1;

		/* should be zero ended, but we are paranoid. */
		s->buffer[s->seq.len] = 0;