diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2016-03-18 15:46:48 -0400 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-04-18 08:51:05 -0400 |
| commit | ab31b690cdf88cf5cb0493718b89dbc37dd784a3 (patch) | |
| tree | 0aca0964ed3d00fd918a440f7a46b3d2a70ab91e /kernel | |
| parent | e4fc9a7c67d779795033235a2b5d2c84e39424c2 (diff) | |
tracing: Fix crash from reading trace_pipe with sendfile
[ Upstream commit a29054d9478d0435ab01b7544da4f674ab13f533 ]
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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 05330494a0df..de6ea94c41bb 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4916,7 +4916,10 @@ static ssize_t tracing_splice_read_pipe(struct file *filp, spd.nr_pages = i; - ret = splice_to_pipe(pipe, &spd); + if (i) + ret = splice_to_pipe(pipe, &spd); + else + ret = 0; out: splice_shrink_spd(&spd); return ret; |