Commit a29054d9 authored Mar 18, 2016 by Steven Rostedt (Red Hat) Committed by Steven Rostedt Mar 18, 2016

tracing: Fix crash from reading trace_pipe with sendfile

If tracing contains data and the trace_pipe file is read with sendfile(),
then it can trigger a NULL pointer dereference and various BUG_ON within the
VM code.

There's a patch to fix this in the splice_to_pipe() code, but it's also a
good idea to not let that happen from trace_pipe either.

Link: http://lkml.kernel.org/r/1457641146-9068-1-git-send-email-rabin@rab.in



Cc: stable@vger.kernel.org # 2.6.30+
Reported-by: Rabin Vincent <rabin.vincent@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

parent cb86e053

kernel/trace/trace.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -4954,7 +4954,10 @@ static ssize_t tracing_splice_read_pipe(struct file *filp,

		spd.nr_pages = i;

		if (i)
		ret = splice_to_pipe(pipe, &spd);
		else
		ret = 0;
		out:
		splice_shrink_spd(&spd);
		return ret;

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