librbd: prevent overflow of discard API result code

Prevent discard/writesame lengths larger than 2GB.

Fixes: http://tracker.ceph.com/issues/21966
Signed-off-by: Jason Dillaman <dillaman@redhat.com>

diff --git a/PendingReleaseNotes b/PendingReleaseNotes
index f88857dad600ca4b691e96a08c537be334980ad3..22ac3955c9965e31cd2a01d085ad1fa15f958feb 100644 (file)
--- a/PendingReleaseNotes
+++ b/PendingReleaseNotes
@@ -50,3 +50,10 @@
   pg-upmap-items` command), we recommend that all mappings be removed (via
   the `ceph osd rm-pg-upmap-items` command) before upgrading to this
   point release.
+
+13.0.0
+------
+
+* The RBD C API's rbd_discard method now enforces a maximum length of
+  2GB to match the C++ API's Image::discard method. This restriction
+  prevents overflow of the result code.

diff --git a/src/librbd/librbd.cc b/src/librbd/librbd.cc
index 86b690815da18bb60bc08e28a49d3b7ea1e7695a..ddcf11be4e7f31bfc6b60d45da287eaf8c04d6ba 100644 (file)
--- a/src/librbd/librbd.cc
+++ b/src/librbd/librbd.cc
@@ -1669,7 +1669,8 @@ namespace librbd {
     tracepoint(librbd, writesame_enter, ictx, ictx->name.c_str(), ictx->snap_name.c_str(),
                ictx->read_only, ofs, len, bl.length() <= 0 ? NULL : bl.c_str(), bl.length(),
                op_flags);
-    if (bl.length() <= 0 || len % bl.length()) {
+    if (bl.length() <= 0 || len % bl.length() ||
+        len > std::numeric_limits<int>::max()) {
       tracepoint(librbd, writesame_exit, -EINVAL);
       return -EINVAL;
     }
@@ -3724,7 +3725,13 @@ extern "C" ssize_t rbd_write2(rbd_image_t image, uint64_t ofs, size_t len,
 extern "C" int rbd_discard(rbd_image_t image, uint64_t ofs, uint64_t len)
 {
   librbd::ImageCtx *ictx = (librbd::ImageCtx *)image;
-  tracepoint(librbd, discard_enter, ictx, ictx->name.c_str(), ictx->snap_name.c_str(), ictx->read_only, ofs, len);
+  tracepoint(librbd, discard_enter, ictx, ictx->name.c_str(),
+             ictx->snap_name.c_str(), ictx->read_only, ofs, len);
+  if (len > std::numeric_limits<int>::max()) {
+    tracepoint(librbd, discard_exit, -EINVAL);
+    return -EINVAL;
+  }
+
   int r = ictx->io_work_queue->discard(ofs, len, ictx->skip_partial_discard);
   tracepoint(librbd, discard_exit, r);
   return r;
@@ -3737,7 +3744,8 @@ extern "C" ssize_t rbd_writesame(rbd_image_t image, uint64_t ofs, size_t len,
   tracepoint(librbd, writesame_enter, ictx, ictx->name.c_str(), ictx->snap_name.c_str(),
              ictx->read_only, ofs, len, data_len == 0 ? NULL : buf, data_len, op_flags);
 
-  if (data_len == 0 || len % data_len) {
+  if (data_len == 0 || len % data_len ||
+      len > std::numeric_limits<int>::max()) {
     tracepoint(librbd, writesame_exit, -EINVAL);
     return -EINVAL;
   }