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 | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -65,7 +65,8 @@ C(INVALID_SORT_MODIFIER,"Invalid sort modifier"), \ C(EMPTY_SORT_FIELD, "Empty sort field"), \ C(TOO_MANY_SORT_FIELDS, "Too many sort fields (Max = 2)"), \ - C(INVALID_SORT_FIELD, "Sort field must be a key or a val"), + C(INVALID_SORT_FIELD, "Sort field must be a key or a val"), \ + C(INVALID_STR_OPERAND, "String type can not be an operand in expression"), #undef C #define C(a, b) HIST_ERR_##a @@ -2140,6 +2141,13 @@ 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. */ + hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str)); + destroy_hist_field(operand1, 0); + ret = -EINVAL; + goto free; + } expr->flags |= operand1->flags & (HIST_FIELD_FL_TIMESTAMP | HIST_FIELD_FL_TIMESTAMP_USECS); @@ -2241,6 +2249,11 @@ static struct hist_field *parse_expr(str operand1 = NULL; goto free; } + if (operand1->flags & HIST_FIELD_FL_STRING) { + hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(operand1_str)); + ret = -EINVAL; + goto free; + } /* rest of string could be another expression e.g. b+c in a+b+c */ operand_flags = 0; @@ -2250,6 +2263,11 @@ static struct hist_field *parse_expr(str operand2 = NULL; goto free; } + if (operand2->flags & HIST_FIELD_FL_STRING) { + hist_err(file->tr, HIST_ERR_INVALID_STR_OPERAND, errpos(str)); + ret = -EINVAL; + goto free; + } ret = check_expr_operands(file->tr, operand1, operand2); if (ret)