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Commit ad452870 authored by Tom Zanussi's avatar Tom Zanussi Committed by Steven Rostedt (VMware)
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tracing: Make sure variable string fields are NULL-terminated 

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: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
parent 48f79473

kernel/trace/trace_events_hist.c

+2 −2
Original line number Diff line number Diff line
@@ -669,7 +669,7 @@ static notrace void trace_event_raw_event_synth(void *__data, 
			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];
@@ -3091,7 +3091,7 @@ static inline void __update_field_vars(struct tracing_map_elt *elt, 
			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);