Merge tag 'ceph-for-5.1-rc3' of git://github.com/ceph/ceph-client

Pull ceph fixes from Ilya Dryomov:
 "A patch to avoid choking on multipage bvecs in the messenger and a
  small use-after-free fix"

* tag 'ceph-for-5.1-rc3' of git://github.com/ceph/ceph-client:
  ceph: fix use-after-free on symlink traversal
  libceph: fix breakage caused by multipage bvecs

fs/ceph/inode.c

@@ -524,6 +524,7 @@ static void ceph_i_callback(struct rcu_head *head)
 	struct inode *inode = container_of(head, struct inode, i_rcu);
 	struct ceph_inode_info *ci = ceph_inode(inode);
 
+	kfree(ci->i_symlink);
 	kmem_cache_free(ceph_inode_cachep, ci);
 }
 
@@ -566,7 +567,6 @@ void ceph_destroy_inode(struct inode *inode)
 		}
 	}
 
-	kfree(ci->i_symlink);
 	while ((n = rb_first(&ci->i_fragtree)) != NULL) {
 		frag = rb_entry(n, struct ceph_inode_frag, node);
 		rb_erase(n, &ci->i_fragtree);

net/ceph/messenger.c

@@ -840,6 +840,7 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
 					size_t bytes)
 {
 	struct ceph_bio_iter *it = &cursor->bio_iter;
+	struct page *page = bio_iter_page(it->bio, it->iter);
 
 	BUG_ON(bytes > cursor->resid);
 	BUG_ON(bytes > bio_iter_len(it->bio, it->iter));
@@ -851,7 +852,8 @@ static bool ceph_msg_data_bio_advance(struct ceph_msg_data_cursor *cursor,
 		return false;   /* no more data */
 	}
 
-	if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done))
+	if (!bytes || (it->iter.bi_size && it->iter.bi_bvec_done &&
+		       page == bio_iter_page(it->bio, it->iter)))
 		return false;	/* more bytes to process in this segment */
 
 	if (!it->iter.bi_size) {
@@ -899,6 +901,7 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
 					size_t bytes)
 {
 	struct bio_vec *bvecs = cursor->data->bvec_pos.bvecs;
+	struct page *page = bvec_iter_page(bvecs, cursor->bvec_iter);
 
 	BUG_ON(bytes > cursor->resid);
 	BUG_ON(bytes > bvec_iter_len(bvecs, cursor->bvec_iter));
@@ -910,7 +913,8 @@ static bool ceph_msg_data_bvecs_advance(struct ceph_msg_data_cursor *cursor,
 		return false;   /* no more data */
 	}
 
-	if (!bytes || cursor->bvec_iter.bi_bvec_done)
+	if (!bytes || (cursor->bvec_iter.bi_bvec_done &&
+		       page == bvec_iter_page(bvecs, cursor->bvec_iter)))
 		return false;	/* more bytes to process in this segment */
 
 	BUG_ON(cursor->last_piece);