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| author | Steven Rostedt (Red Hat) <rostedt@goodmis.org> | 2016-03-18 20:46:48 +0100 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2016-03-18 20:51:42 +0100 |
| commit | a29054d9478d0435ab01b7544da4f674ab13f533 (patch) | |
| tree | 31360ad568f3004066f220cb8a4b16a0489c85a5 | |
| parent | tracing: Have preempt(irqs)off trace preempt disabled functions (diff) | |
| download | linux-a29054d9478d0435ab01b7544da4f674ab13f533.tar.xz linux-a29054d9478d0435ab01b7544da4f674ab13f533.zip | |
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>
| -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 0ae46048f724..cb2b708e4ea7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4954,7 +4954,10 @@ 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; |