pstree: stop truncating thread names

This also fixes a minor buffer overflow when displaying threads as
add_proc() only expects COMM_LEN bytes, but we give it one more than
that.

Reported-by: Dag Wieers <dag@wieers.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>

1 files changed, 10 insertions, 3 deletions

diff --git a/procps/pstree.c b/procps/pstree.c
index 8ba30795d..ea690a9c8 100644
--- a/procps/pstree.c
+++ b/procps/pstree.c
@@ -34,8 +34,15 @@
 
 struct child;
 
+#ifdef ENABLE_FEATURE_SHOW_THREADS
+/* For threads, we add {...} around the comm, so we need two extra bytes */
+# define COMM_DISP_LEN (COMM_LEN + 2)
+#else
+# define COMM_DISP_LEN COMM_LEN
+#endif
+
 typedef struct proc {
-        char comm[COMM_LEN + 1];
+        char comm[COMM_DISP_LEN + 1];
 //      char flags; - unused, delete?
         pid_t pid;
         uid_t uid;
@@ -341,8 +348,8 @@ static void dump_by_user(PROC *current, uid_t uid)
 #if ENABLE_FEATURE_SHOW_THREADS
 static void handle_thread(const char *comm, pid_t pid, pid_t ppid, uid_t uid)
 {
-        char threadname[COMM_LEN + 2];
-        sprintf(threadname, "{%.*s}", COMM_LEN - 2, comm);
+        char threadname[COMM_DISP_LEN + 1];
+        sprintf(threadname, "{%.*s}", (int)sizeof(threadname) - 1, comm);
         add_proc(threadname, pid, ppid, uid/*, 1*/);
 }
 #endif