perf: Fix strncpy() use, always make sure it's NUL terminated

For NUL terminated string, always make sure that there's '\0' at the end.

In our case we need a return value, so still use strncpy() and
fix up the tail explicitly.

(strlcpy() returns the size, not the pointer)

Signed-off-by: Chen Gang <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Cc: [email protected] <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>

1 files changed, 2 insertions, 1 deletions

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 59412d037eed..7f0d67ea3f48 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -4737,7 +4737,8 @@ static void perf_event_mmap_event(struct perf_mmap_event *mmap_event)
 	} else {
 		if (arch_vma_name(mmap_event->vma)) {
 			name = strncpy(tmp, arch_vma_name(mmap_event->vma),
-				       sizeof(tmp));
+				       sizeof(tmp) - 1);
+			tmp[sizeof(tmp) - 1] = '\0';
 			goto got_name;
 		}