From: Adalbert Lazăr alazar@bitdefender.com
commit 4c404ce23358d5d8fbdeb7a6021a9b33d3c3c167 upstream.
Previous to commit 22b5c0b63f32 ("vsock/virtio: fix kernel panic after device hot-unplug"), vsock_core_init() was called from virtio_vsock_probe(). Now, virtio_transport_reset_no_sock() can be called before vsock_core_init() has the chance to run.
[Wed Feb 27 14:17:09 2019] BUG: unable to handle kernel NULL pointer dereference at 0000000000000110 [Wed Feb 27 14:17:09 2019] #PF error: [normal kernel read fault] [Wed Feb 27 14:17:09 2019] PGD 0 P4D 0 [Wed Feb 27 14:17:09 2019] Oops: 0000 [#1] SMP PTI [Wed Feb 27 14:17:09 2019] CPU: 3 PID: 59 Comm: kworker/3:1 Not tainted 5.0.0-rc7-390-generic-hvi #390 [Wed Feb 27 14:17:09 2019] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 [Wed Feb 27 14:17:09 2019] Workqueue: virtio_vsock virtio_transport_rx_work [vmw_vsock_virtio_transport] [Wed Feb 27 14:17:09 2019] RIP: 0010:virtio_transport_reset_no_sock+0x8c/0xc0 [vmw_vsock_virtio_transport_common] [Wed Feb 27 14:17:09 2019] Code: 35 8b 4f 14 48 8b 57 08 31 f6 44 8b 4f 10 44 8b 07 48 8d 7d c8 e8 84 f8 ff ff 48 85 c0 48 89 c3 74 2a e8 f7 31 03 00 48 89 df <48> 8b 80 10 01 00 00 e8 68 fb 69 ed 48 8b 75 f0 65 48 33 34 25 28 [Wed Feb 27 14:17:09 2019] RSP: 0018:ffffb42701ab7d40 EFLAGS: 00010282 [Wed Feb 27 14:17:09 2019] RAX: 0000000000000000 RBX: ffff9d79637ee080 RCX: 0000000000000003 [Wed Feb 27 14:17:09 2019] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9d79637ee080 [Wed Feb 27 14:17:09 2019] RBP: ffffb42701ab7d78 R08: ffff9d796fae70e0 R09: ffff9d796f403500 [Wed Feb 27 14:17:09 2019] R10: ffffb42701ab7d90 R11: 0000000000000000 R12: ffff9d7969d09240 [Wed Feb 27 14:17:09 2019] R13: ffff9d79624e6840 R14: ffff9d7969d09318 R15: ffff9d796d48ff80 [Wed Feb 27 14:17:09 2019] FS: 0000000000000000(0000) GS:ffff9d796fac0000(0000) knlGS:0000000000000000 [Wed Feb 27 14:17:09 2019] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [Wed Feb 27 14:17:09 2019] CR2: 0000000000000110 CR3: 0000000427f22000 CR4: 00000000000006e0 [Wed Feb 27 14:17:09 2019] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [Wed Feb 27 14:17:09 2019] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [Wed Feb 27 14:17:09 2019] Call Trace: [Wed Feb 27 14:17:09 2019] virtio_transport_recv_pkt+0x63/0x820 [vmw_vsock_virtio_transport_common] [Wed Feb 27 14:17:09 2019] ? kfree+0x17e/0x190 [Wed Feb 27 14:17:09 2019] ? detach_buf_split+0x145/0x160 [Wed Feb 27 14:17:09 2019] ? __switch_to_asm+0x40/0x70 [Wed Feb 27 14:17:09 2019] virtio_transport_rx_work+0xa0/0x106 [vmw_vsock_virtio_transport] [Wed Feb 27 14:17:09 2019] NET: Registered protocol family 40 [Wed Feb 27 14:17:09 2019] process_one_work+0x167/0x410 [Wed Feb 27 14:17:09 2019] worker_thread+0x4d/0x460 [Wed Feb 27 14:17:09 2019] kthread+0x105/0x140 [Wed Feb 27 14:17:09 2019] ? rescuer_thread+0x360/0x360 [Wed Feb 27 14:17:09 2019] ? kthread_destroy_worker+0x50/0x50 [Wed Feb 27 14:17:09 2019] ret_from_fork+0x35/0x40 [Wed Feb 27 14:17:09 2019] Modules linked in: vmw_vsock_virtio_transport vmw_vsock_virtio_transport_common input_leds vsock serio_raw i2c_piix4 mac_hid qemu_fw_cfg autofs4 cirrus ttm drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops virtio_net psmouse drm net_failover pata_acpi virtio_blk failover floppy
Fixes: 22b5c0b63f32 ("vsock/virtio: fix kernel panic after device hot-unplug") Reported-by: Alexandru Herghelegiu aherghelegiu@bitdefender.com Signed-off-by: Adalbert Lazăr alazar@bitdefender.com Co-developed-by: Stefan Hajnoczi stefanha@redhat.com Reviewed-by: Stefan Hajnoczi stefanha@redhat.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/vmw_vsock/virtio_transport_common.c | 22 +++++++++++++++------- 1 file changed, 15 insertions(+), 7 deletions(-)
--- a/net/vmw_vsock/virtio_transport_common.c +++ b/net/vmw_vsock/virtio_transport_common.c @@ -601,6 +601,8 @@ static int virtio_transport_reset(struct */ static int virtio_transport_reset_no_sock(struct virtio_vsock_pkt *pkt) { + const struct virtio_transport *t; + struct virtio_vsock_pkt *reply; struct virtio_vsock_pkt_info info = { .op = VIRTIO_VSOCK_OP_RST, .type = le16_to_cpu(pkt->hdr.type), @@ -611,15 +613,21 @@ static int virtio_transport_reset_no_soc if (le16_to_cpu(pkt->hdr.op) == VIRTIO_VSOCK_OP_RST) return 0;
- pkt = virtio_transport_alloc_pkt(&info, 0, - le64_to_cpu(pkt->hdr.dst_cid), - le32_to_cpu(pkt->hdr.dst_port), - le64_to_cpu(pkt->hdr.src_cid), - le32_to_cpu(pkt->hdr.src_port)); - if (!pkt) + reply = virtio_transport_alloc_pkt(&info, 0, + le64_to_cpu(pkt->hdr.dst_cid), + le32_to_cpu(pkt->hdr.dst_port), + le64_to_cpu(pkt->hdr.src_cid), + le32_to_cpu(pkt->hdr.src_port)); + if (!reply) return -ENOMEM;
- return virtio_transport_get_ops()->send_pkt(pkt); + t = virtio_transport_get_ops(); + if (!t) { + virtio_transport_free_pkt(reply); + return -ENOTCONN; + } + + return t->send_pkt(reply); }
static void virtio_transport_wait_close(struct sock *sk, long timeout)