diff --git a/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c b/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c
index c69fdcf4ecd1..ccbbce949c92 100644
--- a/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c
+++ b/external/cddl/osnet/dist/uts/common/fs/zfs/zfs_vnops.c
@@ -6046,7 +6046,13 @@ zfs_putapage(vnode_t *vp, page_t **pp, int count, int flags)
 
 	off = pp[0]->offset;
 	len = count * PAGESIZE;
-	KASSERT(off + len <= round_page(zp->z_size));
+	KASSERT(off <= zp->z_size);
+	KASSERT(len <= round_page(zp->z_size));
+	KASSERT(off <= round_page(zp->z_size) - len);
+	if (off + len > zp->z_size)
+		len = zp->z_size - off;
+	KASSERT(len <= zp->z_size);
+	KASSERT(off <= zp->z_size - len);
 
 	if (zfs_owner_overquota(zfsvfs, zp, B_FALSE) ||
 	    zfs_owner_overquota(zfsvfs, zp, B_TRUE)) {