From mboxrd@z Thu Jan 1 00:00:00 1970 From: wangyunjian Subject: [PATCH] virtio_net: fix virtnet_open and virtnet_probe competing for try_fill_recv Date: Wed, 25 May 2016 20:33:52 +0800 Message-ID: <57459BB0.2000108@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit To: , , , , Return-path: Received: from szxga03-in.huawei.com ([119.145.14.66]:8312 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751127AbcEYMfW (ORCPT ); Wed, 25 May 2016 08:35:22 -0400 Sender: netdev-owner@vger.kernel.org List-ID: In function virtnet_open() and virtnet_probe(), func try_fill_recv() will be executed at the same time. VQ in virtqueue_add() is not protected well and BUG_ON will be triggered when virito_net.ko being removed. Test Script: for (( i=0; i<5000000; i=i+1 )); do rmmod virtio_net modprobe virtio_net ifconfig eth0 up done [ 302.336996] ------------[ cut here ]------------ [ 302.338794] kernel BUG at virtio_ring.c:750! [ 302.340013] invalid opcode: 0000 [#1] SMP [ 302.340013] last sysfs file: /sys/devices/pci0000:00/0000:00:03.0/virtio0/device [ 302.340013] CPU 0 [ 302.340013] Modules linked in: virtio_balloon virtio_net(-) virtio_pci virtio_ring virtio ipv6 af_packet microcode acpiphp pci_hotplug fuse loop dm_mod rtc_cmos tpm_tis rtc_core tpm i2c_piix4 rtc_lib container button floppy pcspkr tpm_bios i2c_core joydev sg usbhid hid uhci_hcd ehci_hcd usbcore edd ext3 mbcache jbd fan processor ide_pci_generic piix ide_core ata_generic at a_piix libata thermal thermal_sys hwmon sd_mod crc_t10dif kvm_ivshmem(N) scsi_mod pv_channel(N) [last unloaded: virtio] [ 302.340013] Supported: Yes [ 302.340013] Pid: 8410, comm: rmmod Tainted: GN 2.6.32.12-0.7-default #1 Standard PC (i440FX + PIIX, 1996) [ 302.340013] RIP: 0010:[] [] virtqueue_detach_unused_buf+0xb9/0xc0 [virtio_ring] [ 302.340013] RSP: 0018:ffff88000c7a9e08 EFLAGS: 00010283 [ 302.340013] RAX: 00000000000000f4 RBX: 0000000000000100 RCX: 0000000000004d8e [ 302.340013] RDX: ffff880001e00000 RSI: 0000000000000046 RDI: ffffffff81a71570 [ 302.340013] RBP: ffff88000c987000 R08: 0000000000000000 R09: 000000000000000a [ 302.340013] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000400 [ 302.340013] R13: 0000000000000000 R14: 00007fff92bc1758 R15: 0000000000000001 [ 302.340013] FS: 00007f8b3995d700(0000) GS:ffff880001e00000(0000) knlGS:0000000000000000 [ 302.340013] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 302.340013] CR2: 00007fff196433e0 CR3: 000000000d07e000 CR4: 00000000000006f0 [ 302.340013] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 302.340013] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 302.340013] Process rmmod (pid: 8410, threadinfo ffff88000c7a8000, task ffff88000c7aa200) [ 302.340013] Stack: [ 302.340013] ffff88000fbb3780 0000000000000000 ffff88000c987000 ffffffffa034b178 [ 302.340013] <0> ffff88000fbb3850 ffff88000fbb3780 ffffffffa034efc0 ffff88000fbb3850 [ 302.340013] <0> 0000000000000000 ffffffffa034b299 ffff88000fbb3780 ffffffffa034b406 [ 302.340013] Call Trace: [ 302.340013] [] free_unused_bufs+0x88/0x120 [virtio_net] [ 302.340013] [] remove_vq_common+0x19/0x30 [virtio_net] [ 302.340013] [] virtnet_remove+0x46/0x80 [virtio_net] [ 302.340013] [] virtio_dev_remove+0x15/0x60 [virtio] [ 302.340013] [] __device_release_driver+0x91/0x110 [ 302.340013] [] driver_detach+0xa8/0xb0 [ 302.340013] [] bus_remove_driver+0x82/0x110 [ 302.340013] [] sys_delete_module+0x1c4/0x290 [ 302.340013] [] system_call_fastpath+0x16/0x1b [ 302.340013] [<00007f8b394c7de7>] 0x7f8b394c7de7 [ 302.340013] Code: c3 01 49 83 c4 04 e8 30 10 07 e1 8b 55 38 39 da 77 d0 8b 75 2c 31 c0 48 c7 c7 ba 4b 32 a0 e8 18 10 07 e1 8b 45 2c 3b 45 38 74 82 <0f> 0b eb fe 0f 1f 00 48 83 ec 28 48 89 6c 24 08 48 89 1c 24 48 [ 302.340013] RIP [] virtqueue_detach_unused_buf+0xb9/0xc0 [virtio_ring] [ 302.340013] RSP [ 302.438579] ---[ end trace 1e583bdb5b2644f1 ]--- Signed-off-by: Yunjian Wang --- drivers/net/virtio_net.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 49d84e5..4528ef8 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -818,10 +818,6 @@ static int virtnet_open(struct net_device *dev) int i; for (i = 0; i < vi->max_queue_pairs; i++) { - if (i < vi->curr_queue_pairs) - /* Make sure we have some buffers: if oom use wq. */ - if (!try_fill_recv(vi, &vi->rq[i], GFP_KERNEL)) - schedule_delayed_work(&vi->refill, 0); virtnet_napi_enable(&vi->rq[i]); }