work around wrong kernel type for sem_nsems member of struct semid_ds

[musl] / src / ipc / semget.c

diff --git a/src/ipc/semget.c b/src/ipc/semget.c
index 5f110e3..c4a559d 100644 (file)
--- a/src/ipc/semget.c
+++ b/src/ipc/semget.c
@@ -1,9 +1,16 @@
 #include <sys/sem.h>
+#include <limits.h>
+#include <errno.h>
 #include "syscall.h"
 #include "ipc.h"
 
 int semget(key_t key, int n, int fl)
 {
+       /* The kernel uses the wrong type for the sem_nsems member
+        * of struct semid_ds, and thus might not check that the
+        * n fits in the correct (per POSIX) userspace type, so
+        * we have to check here. */
+       if (n > USHRT_MAX) return __syscall_ret(-EINVAL);
 #ifdef SYS_semget
        return syscall(SYS_semget, key, n, fl);
 #else