[Devel] [PATCH RHEL9 COMMIT] ms/openvswitch: fix memory leak at failed datapath creation

[Konstantin Khorenko]

The commit is pushed to "branch-rh9-5.14.0-162.18.1.vz9.19.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh9-5.14.0-162.18.1.vz9.19.8
------>
commit aa0db76d2d04cc9e64183dd0b4ae1673c1fd5f34
Author: Andrey Zhadchenko <andrey.zhadchenko at virtuozzo.com>
Date:   Tue Apr 25 13:11:40 2023 +0300

    ms/openvswitch: fix memory leak at failed datapath creation
    
    ovs_dp_cmd_new()->ovs_dp_change()->ovs_dp_set_upcall_portids()
    allocates array via kmalloc.
    If for some reason new_vport() fails during ovs_dp_cmd_new()
    dp->upcall_portids must be freed.
    Add missing kfree.
    
    Kmemleak example:
    unreferenced object 0xffff88800c382500 (size 64):
      comm "dump_state", pid 323, jiffies 4294955418 (age 104.347s)
      hex dump (first 32 bytes):
        5e c2 79 e4 1f 7a 38 c7 09 21 38 0c 80 88 ff ff  ^.y..z8..!8.....
        03 00 00 00 0a 00 00 00 14 00 00 00 28 00 00 00  ............(...
      backtrace:
        [<0000000071bebc9f>] ovs_dp_set_upcall_portids+0x38/0xa0
        [<000000000187d8bd>] ovs_dp_change+0x63/0xe0
        [<000000002397e446>] ovs_dp_cmd_new+0x1f0/0x380
        [<00000000aa06f36e>] genl_family_rcv_msg_doit+0xea/0x150
        [<000000008f583bc4>] genl_rcv_msg+0xdc/0x1e0
        [<00000000fa10e377>] netlink_rcv_skb+0x50/0x100
        [<000000004959cece>] genl_rcv+0x24/0x40
        [<000000004699ac7f>] netlink_unicast+0x23e/0x360
        [<00000000c153573e>] netlink_sendmsg+0x24e/0x4b0
        [<000000006f4aa380>] sock_sendmsg+0x62/0x70
        [<00000000d0068654>] ____sys_sendmsg+0x230/0x270
        [<0000000012dacf7d>] ___sys_sendmsg+0x88/0xd0
        [<0000000011776020>] __sys_sendmsg+0x59/0xa0
        [<000000002e8f2dc1>] do_syscall_64+0x3b/0x90
        [<000000003243e7cb>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
    
    Fixes: b83d23a2a38b ("openvswitch: Introduce per-cpu upcall dispatch")
    Acked-by: Aaron Conole <aconole at redhat.com>
    Signed-off-by: Andrey Zhadchenko <andrey.zhadchenko at virtuozzo.com>
    
    Link: https://lore.kernel.org/r/20220825020326.664073-1-andrey.zhadchenko@virtuozzo.com
    Signed-off-by: Jakub Kicinski <kuba at kernel.org>
    
    (cherry picked from ms commit a87406f4adee9c53b311d8a1ba2849c69e29a6d0)
    Signed-off-by: Andrey Zhadchenko <andrey.zhadchenko at virtuozzo.com>
    
    ======
    Patchset description:
    net/openvswitch: pull ms API
    
    Revert our patch for openvswitch, apply the ones that got accepted
    into mainstream:
    https://lore.kernel.org/all/20220825020450.664147-1-andrey.zhadchenko@virtuozzo.com/
    
    Andrey Zhadchenko (4):
      Revert "net: openvswitch: add capability to specify ifindex of new
        links"
      openvswitch: fix memory leak at failed datapath creation
      openvswitch: allow specifying ifindex of new interfaces
      openvswitch: add OVS_DP_ATTR_PER_CPU_PIDS to get requests
    
    https://jira.vzint.dev/browse/PSBM-147353
    
    Feature: ve: CRIU support
---
 net/openvswitch/datapath.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 7e8a39a35627..6c9d153afbee 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -1802,7 +1802,7 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
 				ovs_dp_reset_user_features(skb, info);
 		}
 
-		goto err_unlock_and_destroy_meters;
+		goto err_destroy_portids;
 	}
 
 	err = ovs_dp_cmd_fill_info(dp, reply, info->snd_portid,
@@ -1817,6 +1817,8 @@ static int ovs_dp_cmd_new(struct sk_buff *skb, struct genl_info *info)
 	ovs_notify(&dp_datapath_genl_family, reply, info);
 	return 0;
 
+err_destroy_portids:
+	kfree(rcu_dereference_raw(dp->upcall_portids));
 err_unlock_and_destroy_meters:
 	ovs_unlock();
 	ovs_meters_exit(dp);