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  1. Mar 01, 2010
    • Michael S. Tsirkin's avatar
      virtio: fix out of range array access · 31198159
      Michael S. Tsirkin authored
      
      
      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: default avatarMichael S. Tsirkin <mst@redhat.com>
      Acked-by: default avatarAnthony Liguori <aliguori@us.ibm.com>
      Acked-by: default avatarShirley Ma <xma@us.ibm.com>
      Acked-by: default avatarAmit Shah <amit.shah@redhat.com>
      31198159
  2. Feb 28, 2010
  3. Feb 27, 2010