diff options
| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2016-03-18 15:46:48 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-12 09:08:59 -0700 |
| commit | aab3ba82f8445abe99f33e743e7316d0d55fee7b (patch) | |
| tree | 6e9069d79eb2578a3d34d86c37e1acedf3388a91 /kernel/trace | |
| parent | aa60f652eeebb8345ed8c543d1a8d6b71f902de3 (diff) | |
tracing: Fix crash from reading trace_pipe with sendfile
commit a29054d9478d0435ab01b7544da4f674ab13f533 upstream.
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
Reported-by: Rabin Vincent <rabin.vincent@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/trace')
| -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 d9293402ee68..8305cbb2d5a2 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4949,7 +4949,10 @@ 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; |