[xen staging-4.12] tools/oxenstored: Fix quota calculation for mkdir EEXIST

[patchbot@xxxxxxx]

commit 1df73ab47bde4a83676f74ed28b48cda9ff881db
Author:     Edwin Török <edvin.torok@xxxxxxxxxx>
AuthorDate: Fri Jan 15 19:11:32 2021 +0000
Commit:     Ian Jackson <iwj@xxxxxxxxxxxxxx>
CommitDate: Fri Mar 19 13:46:44 2021 +0000

    tools/oxenstored: Fix quota calculation for mkdir EEXIST
    
    We increment the domain's quota on mkdir even when the node already exists.
    This results in a quota inconsistency after live update, where 
reconstructing
    the tree from scratch results in a different quota.
    
    Not a security issue because the domain uses up quota faster, so it will 
only
    get a Quota error sooner than it should.
    
    Found by the structured fuzzer.
    
    Signed-off-by: Edwin Török <edvin.torok@xxxxxxxxxx>
    Acked-by: Christian Lindig <christian.lindig@xxxxxxxxxx>
    Release-Acked-by: Ian Jackson <iwj@xxxxxxxxxxxxxx>
    (cherry picked from commit c8b96708252a436da44005307f7c195d699bd7c5)
---
 tools/ocaml/xenstored/store.ml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/ocaml/xenstored/store.ml b/tools/ocaml/xenstored/store.ml
index e20767372f..328d3a5198 100644
--- a/tools/ocaml/xenstored/store.ml
+++ b/tools/ocaml/xenstored/store.ml
@@ -421,6 +421,7 @@ let mkdir store perm path =
        (* It's upt to the mkdir logic to decide what to do with existing path 
*)
        if not (existing || (Perms.Connection.is_dom0 perm)) then Quota.check 
store.quota owner 0;
        store.root <- path_mkdir store perm path;
+       if not existing then
        Quota.add_entry store.quota owner
 
 let rm store perm path =
--
generated by git-patchbot for /home/xen/git/xen.git#staging-4.12