projects/linux·commit 8ab77458

Merge tag 'trace-v5.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

8ab77458 · Linus Torvalds <[email protected]> · 2021-11-14 19:07:19 -08:00

Pull tracing fix from Steven Rostedt:
 "Update to tracing histogram variable string copy

  A fix to only copy the size of the field to the histogram string did
  not take into account that the size can be larger than the storage"

* tag 'trace-v5.16-5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Add length protection to histogram string copies
Commit
8ab774587903771821b59471cc723bba6d893942
Parents
158ea2d2 · 938aa33f

Merge commit. Changes below are compared with the first parent: 158ea2d2.

Changes

2 files changed · +8 −3

FileStatusAddDelContent
include/linux/trace_events.hmodified+1−1View file
kernel/trace/trace_events_hist.cmodified+7−2View file

include/linux/trace_events.h

View file
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 50453b2..2d167ac 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -673,7 +673,7 @@ struct trace_event_file {
#define PERF_MAX_TRACE_SIZE 8192
-#define MAX_FILTER_STR_VAL 256 /* Should handle KSYM_SYMBOL_LEN */
+#define MAX_FILTER_STR_VAL 256U /* Should handle KSYM_SYMBOL_LEN */
enum event_trigger_type {
ETT_NONE = (0),

kernel/trace/trace_events_hist.c

View file
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 8a10046..5ea2c9e 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -3026,8 +3026,10 @@ static inline void __update_field_vars(struct tracing_map_elt *elt,
if (val->flags & HIST_FIELD_FL_STRING) {
char *str = elt_data->field_var_str[j++];
char *val_str = (char *)(uintptr_t)var_val;
+ unsigned int size;
- strscpy(str, val_str, val->size);
+ size = min(val->size, STR_VAR_LEN_MAX);
+ strscpy(str, val_str, size);
var_val = (u64)(uintptr_t)str;
}
tracing_map_set_var(elt, var_idx, var_val);
@@ -4914,6 +4916,7 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
if (hist_field->flags & HIST_FIELD_FL_STRING) {
unsigned int str_start, var_str_idx, idx;
char *str, *val_str;
+ unsigned int size;
str_start = hist_data->n_field_var_str +
hist_data->n_save_var_str;
@@ -4922,7 +4925,9 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data,
str = elt_data->field_var_str[idx];
val_str = (char *)(uintptr_t)hist_val;
- strscpy(str, val_str, hist_field->size);
+
+ size = min(hist_field->size, STR_VAR_LEN_MAX);
+ strscpy(str, val_str, size);
hist_val = (u64)(uintptr_t)str;
}