[PATCH 0/2] tracing: Fix synthetic event bug

[Steven Rostedt]

The follow commands caused a crash:

  # cd /sys/kernel/tracing
  # echo 's:open char file[]' > dynamic_events
  # echo 'hist:keys=common_pid:file=filename:onchange($file).trace(open,$file)' > events/syscalls/sys_enter_openat/trigger'
  # echo 1 > events/synthetic/open/enable

BOOM!

The problem is that the synthetic event field "char file[]" will read
the value given to it as a string without any memory checks to make sure
the address is valid. The above example will pass in the user space
address and the sythetic event code will happily call strlen() on it
and then strscpy() where either one will cause an oops when accessing
user space addresses.


Steven Rostedt (Google) (2):
      tracing: Move duplicate code of trace_kprobe/eprobe.c into header
      tracing: Fix reading strings from synthetic events

----
 kernel/trace/trace_eprobe.c       | 60 ++----------------------
 kernel/trace/trace_events_synth.c | 28 +++++++++---
 kernel/trace/trace_kprobe.c       | 60 ++----------------------
 kernel/trace/trace_probe_kernel.h | 96 +++++++++++++++++++++++++++++++++++++++
 4 files changed, 127 insertions(+), 117 deletions(-)
 create mode 100644 kernel/trace/trace_probe_kernel.h