os/bluestore: null terminate readlink() result

readlink() does not guarantee null termination of result. Signed-off-by: Yehuda Sadeh <[email protected]>
att · Nov 7, 2016 · bfdf2c6 · bfdf2c6
1 parent 20c3fd8
commit bfdf2c6
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/src/os/bluestore/BlockDevice.cc b/src/os/bluestore/BlockDevice.cc
@@ -46,9 +46,10 @@ void IOContext::aio_wait()
 BlockDevice *BlockDevice::create(const string& path, aio_callback_t cb, void *cbpriv)
 {
   string type = "kernel";
-  char buf[PATH_MAX];
-  int r = ::readlink(path.c_str(), buf, sizeof(buf));
+  char buf[PATH_MAX + 1];
+  int r = ::readlink(path.c_str(), buf, sizeof(buf) - 1);
   if (r >= 0) {
+    buf[r] = '\0';
     char *bname = ::basename(buf);
     if (strncmp(bname, SPDK_PREFIX, sizeof(SPDK_PREFIX)-1) == 0)
       type = "ust-nvme";