getservbyport_r: fix out-of-bounds buffer read

[musl] / src / stdio / ftrylockfile.c

diff --git a/src/stdio/ftrylockfile.c b/src/stdio/ftrylockfile.c
index 3b1d5f2..5065058 100644 (file)
--- a/src/stdio/ftrylockfile.c
+++ b/src/stdio/ftrylockfile.c
@@ -2,8 +2,6 @@
 #include "pthread_impl.h"
 #include <limits.h>
 
-#define MAYBE_WAITERS 0x40000000
-
 void __do_orphaned_stdio_locks()
 {
        FILE *f;
@@ -20,6 +18,15 @@ void __unlist_locked_file(FILE *f)
        }
 }
 
+void __register_locked_file(FILE *f, pthread_t self)
+{
+       f->lockcount = 1;
+       f->prev_locked = 0;
+       f->next_locked = self->stdio_locks;
+       if (f->next_locked) f->next_locked->prev_locked = f;
+       self->stdio_locks = f;
+}
+
 int ftrylockfile(FILE *f)
 {
        pthread_t self = __pthread_self();
@@ -34,10 +41,6 @@ int ftrylockfile(FILE *f)
        if (owner < 0) f->lock = owner = 0;
        if (owner || a_cas(&f->lock, 0, tid))
                return -1;
-       f->lockcount = 1;
-       f->prev_locked = 0;
-       f->next_locked = self->stdio_locks;
-       if (f->next_locked) f->next_locked->prev_locked = f;
-       self->stdio_locks = f;
+       __register_locked_file(f, self);
        return 0;
 }