From: Masami Hiramatsu <mhiramat@xxxxxxxxxx> 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@devnote2 Cc: stable@xxxxxxxxxxxxxxx Fixes: 100719dcef447 ("tracing: Add simple expression support to hist triggers") Signed-off-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/trace/trace_events_hist.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2790,6 +2790,12 @@ static struct hist_field *parse_unary(st 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); @@ -2890,6 +2896,10 @@ static struct hist_field *parse_expr(str 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; @@ -2899,6 +2909,10 @@ static struct hist_field *parse_expr(str operand2 = NULL; goto free; } + if (operand2->flags & HIST_FIELD_FL_STRING) { + ret = -EINVAL; + goto free; + } ret = check_expr_operands(operand1, operand2); if (ret)
