From 27242c62b141240079d1ac8d35adcdc70cae8895 Mon Sep 17 00:00:00 2001 From: Tom Zanussi <tom.zanussi@linux.intel.com> Date: Tue, 5 Mar 2019 10:11:59 -0600 Subject: [PATCH] tracing: Use strncpy instead of memcpy when copying comm for hist triggers Because there may be random garbage beyond a string's null terminator, code that might use the entire comm array e.g. histogram keys, can give unexpected results if that garbage is copied in too, so avoid that possibility by using strncpy instead of memcpy. Link: http://lkml.kernel.org/r/1eb9f096a8086c3c82c7fc087c900005143cec54.1551802084.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> --- kernel/trace/trace_events_hist.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index c7774fa119a7c..ca46339f30090 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -2141,7 +2141,7 @@ static inline void save_comm(char *comm, struct task_struct *task) return; } - memcpy(comm, task->comm, TASK_COMM_LEN); + strncpy(comm, task->comm, TASK_COMM_LEN); } static void hist_elt_data_free(struct hist_elt_data *elt_data) @@ -3557,7 +3557,7 @@ static bool cond_snapshot_update(struct trace_array *tr, void *cond_data) elt_data = context->elt->private_data; track_elt_data = track_data->elt.private_data; if (elt_data->comm) - memcpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN); + strncpy(track_elt_data->comm, elt_data->comm, TASK_COMM_LEN); track_data->updated = true; -- GitLab