diff mbox series

[47/54] tracing: Make sure variable string fields are NULL-terminated

Message ID TY1PR01MB1692AF3E473F161BED31914696090@TY1PR01MB1692.jpnprd01.prod.outlook.com (mailing list archive)
State New, archived
Headers show
Series [01/54] tracing: Remove redundant unread variable ret | expand

Commit Message

Motai.Hirotaka@aj.MitsubishiElectric.co.jp Aug. 29, 2018, 12:17 p.m. UTC 
The strncpy() currently being used for variable string fields can
result in a lack of termination if the string length is equal to the
field size.  Use the safer strscpy() instead, which will guarantee
termination.

Link: http://lkml.kernel.org/r/fb97c1e518fb358c12a4057d7445ba2c46956cd7.1522256721.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
(cherry picked from commit ad452870c66e05819a99b491b500a13989a1c502)
Signed-off-by: Hirotaka MOTAI <Motai.Hirotaka@aj.MitsubishiElectric.co.jp>
---
 kernel/trace/trace_events_hist.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 6114939f..15ea11c2 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -664,17 +664,17 @@  static notrace void trace_event_raw_event_synth(void *__data,
 	if (!entry)
 		goto out;
 
 	for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
 		if (event->fields[i]->is_string) {
 			char *str_val = (char *)(long)var_ref_vals[var_ref_idx + i];
 			char *str_field = (char *)&entry->fields[n_u64];
 
-			strncpy(str_field, str_val, STR_VAR_LEN_MAX);
+			strscpy(str_field, str_val, STR_VAR_LEN_MAX);
 			n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
 		} else {
 			entry->fields[n_u64] = var_ref_vals[var_ref_idx + i];
 			n_u64++;
 		}
 	}
 
 	trace_event_buffer_commit(&fbuffer);
@@ -3086,17 +3086,17 @@  static inline void __update_field_vars(struct tracing_map_elt *elt,
 
 		var_val = val->fn(val, elt, rbe, rec);
 		var_idx = var->var.idx;
 
 		if (val->flags & HIST_FIELD_FL_STRING) {
 			char *str = elt_data->field_var_str[j++];
 			char *val_str = (char *)(uintptr_t)var_val;
 
-			strncpy(str, val_str, STR_VAR_LEN_MAX);
+			strscpy(str, val_str, STR_VAR_LEN_MAX);
 			var_val = (u64)(uintptr_t)str;
 		}
 		tracing_map_set_var(elt, var_idx, var_val);
 	}
 }
 
 static void update_field_vars(struct hist_trigger_data *hist_data,
 			      struct tracing_map_elt *elt,