commit a9d10ca4986571bffc19778742d508cc8dd13e02 upstream
Since the string type can not be the target of the addition / subtraction operation, it must be rejected. Without this fix, the string type silently converted to digits.
Link: https://lkml.kernel.org/r/162742654278.290973.1523000673366456634.stgit@devn...
Cc: stable@vger.kernel.org Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers") Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- - Since there is no hist_err() APIs in 4.19, this just check the flag and return an error without any error messages. --- kernel/trace/trace_events_hist.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+)
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 28e4ff45cb4c..e9106c976a48 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2781,6 +2781,12 @@ static struct hist_field *parse_unary(struct hist_trigger_data *hist_data, ret = PTR_ERR(operand1); goto free; } + if (operand1->flags & HIST_FIELD_FL_STRING) { + /* String type can not be the operand of unary operator. */ + destroy_hist_field(operand1, 0); + ret = -EINVAL; + goto free; + }
expr->flags |= operand1->flags & (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); @@ -2881,6 +2887,10 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, operand1 = NULL; goto free; } + if (operand1->flags & HIST_FIELD_FL_STRING) { + ret = -EINVAL; + goto free; + }
/* rest of string could be another expression e.g. b+c in a+b+c */ operand_flags = 0; @@ -2890,6 +2900,10 @@ static struct hist_field *parse_expr(struct hist_trigger_data *hist_data, operand2 = NULL; goto free; } + if (operand2->flags & HIST_FIELD_FL_STRING) { + ret = -EINVAL; + goto free; + }
ret = check_expr_operands(operand1, operand2); if (ret)