Re: [BUGFIX PATCH] tracing/kprobes: Fix strpbrk() argument order

From: Steven Rostedt
Date: Thu Nov 01 2018 - 15:10:20 EST


On Thu, 1 Nov 2018 23:29:28 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Fix strpbrk()'s argument order, it must pass acceptable string
> in 2nd argument. Note that this can cause a kernel panic where
> it recovers backup character to code->data.
>
> Fixes: a6682814f371 ("tracing/kprobes: Allow kprobe-events to record module symbol")
> Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>

Thanks Masami,

I'm pulling this and starting to test it.

-- Steve

> ---
> kernel/trace/trace_probe.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
> index 3ef15a6683c0..bd30e9398d2a 100644
> --- a/kernel/trace/trace_probe.c
> +++ b/kernel/trace/trace_probe.c
> @@ -535,7 +535,7 @@ int traceprobe_update_arg(struct probe_arg *arg)
> if (code[1].op != FETCH_OP_IMM)
> return -EINVAL;
>
> - tmp = strpbrk("+-", code->data);
> + tmp = strpbrk(code->data, "+-");
> if (tmp)
> c = *tmp;
> ret = traceprobe_split_symbol_offset(code->data,