[PATCH v2 13/18] rtla: Fix buffer size for strncpy in timerlat_aa
From: Wander Lairson Costa
Date: Tue Jan 06 2026 - 08:45:57 EST
The run_thread_comm and current_comm character arrays in struct
timerlat_aa_data are defined with size MAX_COMM (24 bytes), but
strncpy() is called with MAX_COMM as the size parameter. If the
source string is exactly MAX_COMM bytes or longer, strncpy() will
copy exactly MAX_COMM bytes without null termination, potentially
causing buffer overruns when these strings are later used.
Increase the buffer sizes to MAX_COMM+1 to ensure there is always
room for the null terminator. This guarantees that even when strncpy()
copies the maximum number of characters, the buffer remains properly
null-terminated and safe to use in subsequent string operations.
Signed-off-by: Wander Lairson Costa <wander@xxxxxxxxxx>
---
tools/tracing/rtla/src/timerlat_aa.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/tracing/rtla/src/timerlat_aa.c b/tools/tracing/rtla/src/timerlat_aa.c
index 31e66ea2b144c..d310fe65abace 100644
--- a/tools/tracing/rtla/src/timerlat_aa.c
+++ b/tools/tracing/rtla/src/timerlat_aa.c
@@ -47,7 +47,7 @@ struct timerlat_aa_data {
* note: "unsigned long long" because they are fetch using tep_get_field_val();
*/
unsigned long long run_thread_pid;
- char run_thread_comm[MAX_COMM];
+ char run_thread_comm[MAX_COMM+1];
unsigned long long thread_blocking_duration;
unsigned long long max_exit_idle_latency;
@@ -88,7 +88,7 @@ struct timerlat_aa_data {
/*
* Current thread.
*/
- char current_comm[MAX_COMM];
+ char current_comm[MAX_COMM+1];
unsigned long long current_pid;
/*
--
2.52.0