Messages in this thread Patch in this message | | | Date | Thu, 25 Feb 2010 19:13:41 +0200 | From | "Michael S. Tsirkin" <> | Subject | [PATCH] virtio: fix out of range array access |
| |
I have observed the following error on virtio-net module unload:
------------[ cut here ]------------ WARNING: at kernel/irq/manage.c:858 __free_irq+0xa0/0x14c() Hardware name: Bochs Trying to free already-free IRQ 0 Modules linked in: virtio_net(-) virtio_blk virtio_pci virtio_ring virtio af_packet e1000 shpchp aacraid uhci_hcd ohci_hcd ehci_hcd [last unloaded: scsi_wait_scan] Pid: 1957, comm: rmmod Not tainted 2.6.33-rc8-vhost #24 Call Trace: [<ffffffff8103e195>] warn_slowpath_common+0x7c/0x94 [<ffffffff8103e204>] warn_slowpath_fmt+0x41/0x43 [<ffffffff810a7a36>] ? __free_pages+0x5a/0x70 [<ffffffff8107cc00>] __free_irq+0xa0/0x14c [<ffffffff8107cceb>] free_irq+0x3f/0x65 [<ffffffffa0081424>] vp_del_vqs+0x81/0xb1 [virtio_pci] [<ffffffffa0091d29>] virtnet_remove+0xda/0x10b [virtio_net] [<ffffffffa0075200>] virtio_dev_remove+0x22/0x4a [virtio] [<ffffffff812709ee>] __device_release_driver+0x66/0xac [<ffffffff81270ab7>] driver_detach+0x83/0xa9 [<ffffffff8126fc66>] bus_remove_driver+0x91/0xb4 [<ffffffff81270fcf>] driver_unregister+0x6c/0x74 [<ffffffffa0075418>] unregister_virtio_driver+0xe/0x10 [virtio] [<ffffffffa0091c4d>] fini+0x15/0x17 [virtio_net] [<ffffffff8106997b>] sys_delete_module+0x1c3/0x230 [<ffffffff81007465>] ? old_ich_force_enable_hpet+0x117/0x164 [<ffffffff813bb720>] ? do_page_fault+0x29c/0x2cc [<ffffffff81028e58>] sysenter_dispatch+0x7/0x27 ---[ end trace 15e88e4c576cc62b ]---
The bug is in virtio-pci: we use msix_vector as array index to get irq entry, but some vqs do not have a dedicated vector so this causes an out of bounds access. By chance, we seem to often get 0 value, which results in this error.
Fix by verifying that vector is legal before using it as index.
Signed-off-by: Michael S. Tsirkin <mst@redhat.com> --- Shirley, Amit, with Rusty on vacation, need other reviewers. Could you please review the following patch and ack on list if appropriate?
drivers/virtio/virtio_pci.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index 28d9cf7..7127bfe 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -473,7 +473,8 @@ static void vp_del_vqs(struct virtio_device *vdev) list_for_each_entry_safe(vq, n, &vdev->vqs, list) { info = vq->priv; - if (vp_dev->per_vq_vectors) + if (vp_dev->per_vq_vectors && + info->msix_vector != VIRTIO_MSI_NO_VECTOR) free_irq(vp_dev->msix_entries[info->msix_vector].vector, vq); vp_del_vq(vq); -- 1.7.0.18.g0d53a5
| |