[Devel] [PATCH RHEL7 COMMIT] ploop: fix typo in ploop_pb_get_first_req_from_tree

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-514.26.1.vz7.33.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-514.26.1.vz7.33.5
------>
commit b6bd12ecf7c66c26883843d9dc58c0964dc1c0a8
Author: Maxim Patlasov <mpatlasov at virtuozzo.com>
Date:   Thu Jul 13 14:49:09 2017 +0400

    ploop: fix typo in ploop_pb_get_first_req_from_tree
    
    Due to a typo, local pointer was defined as static leading to a nasty race:
    
    1. Thread A (handling ploopN) initializes that pointer
    2. Thread B (handling ploopM) re-initialize the same pointer
    3. Thread A proceeds with using the pointer that currently points to
    some request belonging to ploopM.
    
    Hence data (ploop requests) leaked from one ploop device to another
    leading to list corruption.
    
    https://jira.sw.ru/browse/PSBM-67513
    
    Signed-off-by: Maxim Patlasov <mpatlasov at virtuozzo.com>
---
 drivers/block/ploop/push_backup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/ploop/push_backup.c b/drivers/block/ploop/push_backup.c
index ade5fa5..032706e 100644
--- a/drivers/block/ploop/push_backup.c
+++ b/drivers/block/ploop/push_backup.c
@@ -598,7 +598,7 @@ ploop_pb_get_first_req_from_tree(struct pb_set *pbs,
 				 unsigned old_owner)
 {
 	struct rb_root *tree = &pbs->tree;
-	static struct ploop_request *p;
+	struct ploop_request *p;
 	struct rb_node *n = rb_first(tree);
 
 	if (!n)