From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> commit 450fec13d9170127678f991698ac1a5b05c02e2f upstream. When comparing two strings for the "onmatch" histogram trigger, fields that are strings use string comparisons, which do not care about being signed or not. Do not fail to match two string fields if one is unsigned char array and the other is a signed char array. Link: https://lore.kernel.org/all/20211129123043.5cfd687a@xxxxxxxxxxxxxxxxxx/ Cc: stable@xxxxxxxxxxxxxxxx Cc: Tom Zanussi <zanussi@xxxxxxxxxx> Cc: Yafang Shao <laoar.shao@xxxxxxxxx> Fixes: b05e89ae7cf3b ("tracing: Accept different type for synthetic event fields") Reviewed-by: Masami Hiramatsu <mhiramatsu@xxxxxxxxxx> Reported-by: Sven Schnelle <svens@xxxxxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/trace_events_hist.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -3419,7 +3419,7 @@ static int check_synth_field(struct synt if (strcmp(field->type, hist_field->type) != 0) { if (field->size != hist_field->size || - field->is_signed != hist_field->is_signed) + (!field->is_string && field->is_signed != hist_field->is_signed)) return -EINVAL; }