Add write() check

1 files changed, 13 insertions, 0 deletions

diff --git a/include/unistd.h b/include/unistd.h
index b13b507..c2f5feb 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -60,6 +60,17 @@ __fortify_read(int fd, void *buf, size_t n)
         return read(fd, buf, n);
 }
 
+static inline __attribute__ ((always_inline))
+ssize_t
+__fortify_write(int fd, const void *buf, size_t n)
+{
+        size_t bos = __builtin_object_size(buf, 0);
+
+        if (n > bos)
+                __builtin_trap();
+        return write(fd, buf, n);
+}
+
 #undef confstr
 #define confstr(name, buf, len) __fortify_confstr(name, buf, len)
 #undef getcwd
@@ -70,6 +81,8 @@ __fortify_read(int fd, void *buf, size_t n)
 #define pread(fd, buf, n, offset) __fortify_pread(fd, buf, n, offset)
 #undef read
 #define read(fd, buf, n) __fortify_read(fd, buf, n)
+#undef write
+#define write(fd, buf, n) __fortify_write(fd, buf, n)
 
 #endif