Re: [PATCH] net: openvswitch: free vport unless register_netdevice() succeeds
From: Pravin Shelar
Date: Sat Aug 10 2019 - 03:33:48 EST
On Thu, Aug 8, 2019 at 8:55 PM Hillf Danton <hdanton@xxxxxxxx> wrote:
>
>
> syzbot found the following crash on:
>
> HEAD commit: 1e78030e Merge tag 'mmc-v5.3-rc1' of git://git.kernel.org/..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=148d3d1a600000
> kernel config: https://syzkaller.appspot.com/x/.config?x=30cef20daf3e9977
> dashboard link: https://syzkaller.appspot.com/bug?extid=13210896153522fe1ee5
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=136aa8c4600000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=109ba792600000
>
> =====================================================================
> BUG: memory leak
> unreferenced object 0xffff8881207e4100 (size 128):
> comm "syz-executor032", pid 7014, jiffies 4294944027 (age 13.830s)
> hex dump (first 32 bytes):
> 00 70 16 18 81 88 ff ff 80 af 8c 22 81 88 ff ff .p........."....
> 00 b6 23 17 81 88 ff ff 00 00 00 00 00 00 00 00 ..#.............
> backtrace:
> [<000000000eb78212>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
> [<000000000eb78212>] slab_post_alloc_hook mm/slab.h:522 [inline]
> [<000000000eb78212>] slab_alloc mm/slab.c:3319 [inline]
> [<000000000eb78212>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3548
> [<00000000006ea6c6>] kmalloc include/linux/slab.h:552 [inline]
> [<00000000006ea6c6>] kzalloc include/linux/slab.h:748 [inline]
> [<00000000006ea6c6>] ovs_vport_alloc+0x37/0xf0 net/openvswitch/vport.c:130
> [<00000000f9a04a7d>] internal_dev_create+0x24/0x1d0 net/openvswitch/vport-internal_dev.c:164
> [<0000000056ee7c13>] ovs_vport_add+0x81/0x190 net/openvswitch/vport.c:199
> [<000000005434efc7>] new_vport+0x19/0x80 net/openvswitch/datapath.c:194
> [<00000000b7b253f1>] ovs_dp_cmd_new+0x22f/0x410 net/openvswitch/datapath.c:1614
> [<00000000e0988518>] genl_family_rcv_msg+0x2ab/0x5b0 net/netlink/genetlink.c:629
> [<00000000d0cc9347>] genl_rcv_msg+0x54/0x9c net/netlink/genetlink.c:654
> [<000000006694b647>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477
> [<0000000088381f37>] genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
> [<00000000dad42a47>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
> [<00000000dad42a47>] netlink_unicast+0x1ec/0x2d0 net/netlink/af_netlink.c:1328
> [<0000000067e6b079>] netlink_sendmsg+0x270/0x480 net/netlink/af_netlink.c:1917
> [<00000000aab08a47>] sock_sendmsg_nosec net/socket.c:637 [inline]
> [<00000000aab08a47>] sock_sendmsg+0x54/0x70 net/socket.c:657
> [<000000004cb7c11d>] ___sys_sendmsg+0x393/0x3c0 net/socket.c:2311
> [<00000000c4901c63>] __sys_sendmsg+0x80/0xf0 net/socket.c:2356
> [<00000000c10abb2d>] __do_sys_sendmsg net/socket.c:2365 [inline]
> [<00000000c10abb2d>] __se_sys_sendmsg net/socket.c:2363 [inline]
> [<00000000c10abb2d>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2363
>
> BUG: memory leak
> unreferenced object 0xffff88811723b600 (size 64):
> comm "syz-executor032", pid 7014, jiffies 4294944027 (age 13.830s)
> hex dump (first 32 bytes):
> 01 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................
> 00 00 00 00 00 00 00 00 02 00 00 00 05 35 82 c1 .............5..
> backtrace:
> [<00000000352f46d8>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
> [<00000000352f46d8>] slab_post_alloc_hook mm/slab.h:522 [inline]
> [<00000000352f46d8>] slab_alloc mm/slab.c:3319 [inline]
> [<00000000352f46d8>] __do_kmalloc mm/slab.c:3653 [inline]
> [<00000000352f46d8>] __kmalloc+0x169/0x300 mm/slab.c:3664
> [<000000008e48f3d1>] kmalloc include/linux/slab.h:557 [inline]
> [<000000008e48f3d1>] ovs_vport_set_upcall_portids+0x54/0xd0 net/openvswitch/vport.c:343
> [<00000000541e4f4a>] ovs_vport_alloc+0x7f/0xf0 net/openvswitch/vport.c:139
> [<00000000f9a04a7d>] internal_dev_create+0x24/0x1d0 net/openvswitch/vport-internal_dev.c:164
> [<0000000056ee7c13>] ovs_vport_add+0x81/0x190 net/openvswitch/vport.c:199
> [<000000005434efc7>] new_vport+0x19/0x80 net/openvswitch/datapath.c:194
> [<00000000b7b253f1>] ovs_dp_cmd_new+0x22f/0x410 net/openvswitch/datapath.c:1614
> [<00000000e0988518>] genl_family_rcv_msg+0x2ab/0x5b0 net/netlink/genetlink.c:629
> [<00000000d0cc9347>] genl_rcv_msg+0x54/0x9c net/netlink/genetlink.c:654
> [<000000006694b647>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477
> [<0000000088381f37>] genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
> [<00000000dad42a47>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
> [<00000000dad42a47>] netlink_unicast+0x1ec/0x2d0 net/netlink/af_netlink.c:1328
> [<0000000067e6b079>] netlink_sendmsg+0x270/0x480 net/netlink/af_netlink.c:1917
> [<00000000aab08a47>] sock_sendmsg_nosec net/socket.c:637 [inline]
> [<00000000aab08a47>] sock_sendmsg+0x54/0x70 net/socket.c:657
> [<000000004cb7c11d>] ___sys_sendmsg+0x393/0x3c0 net/socket.c:2311
> [<00000000c4901c63>] __sys_sendmsg+0x80/0xf0 net/socket.c:2356
>
> BUG: memory leak
> unreferenced object 0xffff8881228ca500 (size 128):
> comm "syz-executor032", pid 7015, jiffies 4294944622 (age 7.880s)
> hex dump (first 32 bytes):
> 00 f0 27 18 81 88 ff ff 80 ac 8c 22 81 88 ff ff ..'........"....
> 40 b7 23 17 81 88 ff ff 00 00 00 00 00 00 00 00 @.#.............
> backtrace:
> [<000000000eb78212>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline]
> [<000000000eb78212>] slab_post_alloc_hook mm/slab.h:522 [inline]
> [<000000000eb78212>] slab_alloc mm/slab.c:3319 [inline]
> [<000000000eb78212>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3548
> [<00000000006ea6c6>] kmalloc include/linux/slab.h:552 [inline]
> [<00000000006ea6c6>] kzalloc include/linux/slab.h:748 [inline]
> [<00000000006ea6c6>] ovs_vport_alloc+0x37/0xf0 net/openvswitch/vport.c:130
> [<00000000f9a04a7d>] internal_dev_create+0x24/0x1d0 net/openvswitch/vport-internal_dev.c:164
> [<0000000056ee7c13>] ovs_vport_add+0x81/0x190 net/openvswitch/vport.c:199
> [<000000005434efc7>] new_vport+0x19/0x80 net/openvswitch/datapath.c:194
> [<00000000b7b253f1>] ovs_dp_cmd_new+0x22f/0x410 net/openvswitch/datapath.c:1614
> [<00000000e0988518>] genl_family_rcv_msg+0x2ab/0x5b0 net/netlink/genetlink.c:629
> [<00000000d0cc9347>] genl_rcv_msg+0x54/0x9c net/netlink/genetlink.c:654
> [<000000006694b647>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477
> [<0000000088381f37>] genl_rcv+0x29/0x40 net/netlink/genetlink.c:665
> [<00000000dad42a47>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
> [<00000000dad42a47>] netlink_unicast+0x1ec/0x2d0 net/netlink/af_netlink.c:1328
> [<0000000067e6b079>] netlink_sendmsg+0x270/0x480 net/netlink/af_netlink.c:1917
> [<00000000aab08a47>] sock_sendmsg_nosec net/socket.c:637 [inline]
> [<00000000aab08a47>] sock_sendmsg+0x54/0x70 net/socket.c:657
> [<000000004cb7c11d>] ___sys_sendmsg+0x393/0x3c0 net/socket.c:2311
> [<00000000c4901c63>] __sys_sendmsg+0x80/0xf0 net/socket.c:2356
> [<00000000c10abb2d>] __do_sys_sendmsg net/socket.c:2365 [inline]
> [<00000000c10abb2d>] __se_sys_sendmsg net/socket.c:2363 [inline]
> [<00000000c10abb2d>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2363
> =====================================================================
>
> The function in net core, register_netdevice(), may fail with vport's
> destruction callback either invoked or not. After commit 309b66970ee2,
> the duty to destroy vport is offloaded from the driver OTOH, which ends
> up in the memory leak reported.
>
> It is fixed by releasing vport unless device is registered successfully.
> To do that, the callback assignment is defered until device is registered.
>
> Reported-by: syzbot+13210896153522fe1ee5@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: 309b66970ee2 ("net: openvswitch: do not free vport if register_netdevice() is failed.")
> Cc: Taehee Yoo <ap420073@xxxxxxxxx>
> Cc: Greg Rose <gvrose8192@xxxxxxxxx>
> Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
> Cc: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
> Cc: Ying Xue <ying.xue@xxxxxxxxxxxxx>
> Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
> Signed-off-by: Hillf Danton <hdanton@xxxxxxxx>
> ---
>
> --- a/net/openvswitch/vport-internal_dev.c
> +++ b/net/openvswitch/vport-internal_dev.c
> @@ -137,7 +137,7 @@ static void do_setup(struct net_device *
> netdev->priv_flags |= IFF_LIVE_ADDR_CHANGE | IFF_OPENVSWITCH |
> IFF_NO_QUEUE;
> netdev->needs_free_netdev = true;
> - netdev->priv_destructor = internal_dev_destructor;
> + netdev->priv_destructor = NULL;
> netdev->ethtool_ops = &internal_dev_ethtool_ops;
> netdev->rtnl_link_ops = &internal_dev_link_ops;
>
> @@ -159,7 +159,6 @@ static struct vport *internal_dev_create
> struct internal_dev *internal_dev;
> struct net_device *dev;
> int err;
> - bool free_vport = true;
>
> vport = ovs_vport_alloc(0, &ovs_internal_vport_ops, parms);
> if (IS_ERR(vport)) {
> @@ -190,10 +189,9 @@ static struct vport *internal_dev_create
>
> rtnl_lock();
> err = register_netdevice(vport->dev);
> - if (err) {
> - free_vport = false;
> + if (err)
> goto error_unlock;
> - }
> + vport->dev->priv_destructor = internal_dev_destructor;
>
Looks good.
Acked-by: Pravin B Shelar <pshelar@xxxxxxx>
Thanks,
Pravin.