Re: [PATCH] libtraceevent: Handle case of unknown operator

Hello Steve,

On 19/11/2024 21:18, Steven Rostedt wrote:
> From: "Steven Rostedt (Google)" <[email protected]>
> 
> The m68k architecture had a trace event with "m68k_memory[0].addr >> 13"
> in it. The parsing after the ']' and before the '.' checked the priority
> of the '.' but because it does not handle '.' as an operator it returned a
> negative number. But process_op() did not check for an error and continued
> processing. This caused a segfault.
> 
> Return immediately if the operator is not handled by get_op_prio().
> 
> Link: https://lore.kernel.org/all/[email protected]/
> 
> Reported-by: Jean-Michel Hautbois <[email protected]>
> Fixes: 6582b0aea1cc ("tools/events: Add files to create libtraceevent.a")
> Signed-off-by: Steven Rostedt (Google) <[email protected]>

Thank you for your patch !
Tested-by: Jean-Michel Hautbois <[email protected]>

> ---
>   src/event-parse.c | 4 ++++
>   1 file changed, 4 insertions(+)
> 
> diff --git a/src/event-parse.c b/src/event-parse.c
> index 0427061603db..a6da8f04cbf3 100644
> --- a/src/event-parse.c
> +++ b/src/event-parse.c
> @@ -2498,6 +2498,10 @@ process_op(struct tep_event *event, struct tep_print_arg *arg, char **tok)
>   
>   		/* higher prios need to be closer to the root */
>   		prio = get_op_prio(*tok);
> +		if (prio < 0) {
> +			token = *tok;
> +			goto out_free;
> +		}
>   
>   		if (prio > arg->op.prio)
>   			return process_op(event, arg, tok);