Messages in this thread | | | Date | Tue, 11 Oct 2022 17:25:01 -0400 | From | Steven Rostedt <> | Subject | [PATCH 0/2] tracing: Fix synthetic event bug |
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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
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