Subject: Re: [PATCH net-next v2 2/3] openvswitch: fix memory leak at failed datapath creation

From: Aaron Conole <[email-masked]>
Date: Mon, 22 Aug 2022 08:53:44 -0400

Andrey Zhadchenko <[email-masked]> writes:

> 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")
> Signed-off-by: Andrey Zhadchenko <[email-masked]>
> ---

Thanks for this patch.  I guess independent of this series, this patch
should be applied to the net tree as well - it fixes an existing issue.

Acked-by: Aaron Conole <[email-masked]>

I will try as well the other patches in the series.