Bug 2348177 (CVE-2022-49687) - CVE-2022-49687 kernel: virtio_net: fix xdp_rxq_info bug after suspend/resume
Summary: CVE-2022-49687 kernel: virtio_net: fix xdp_rxq_info bug after suspend/resume
Keywords:
Status: NEW
Alias: CVE-2022-49687
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-02-26 03:20 UTC by OSIDB Bzimport
Modified: 2025-02-27 08:07 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2025-02-26 03:20:17 UTC
In the Linux kernel, the following vulnerability has been resolved:

virtio_net: fix xdp_rxq_info bug after suspend/resume

The following sequence currently causes a driver bug warning
when using virtio_net:

  # ip link set eth0 up
  # echo mem > /sys/power/state (or e.g. # rtcwake -s 10 -m mem)
  <resume>
  # ip link set eth0 down

  Missing register, driver bug
  WARNING: CPU: 0 PID: 375 at net/core/xdp.c:138 xdp_rxq_info_unreg+0x58/0x60
  Call trace:
   xdp_rxq_info_unreg+0x58/0x60
   virtnet_close+0x58/0xac
   __dev_close_many+0xac/0x140
   __dev_change_flags+0xd8/0x210
   dev_change_flags+0x24/0x64
   do_setlink+0x230/0xdd0
   ...

This happens because virtnet_freeze() frees the receive_queue
completely (including struct xdp_rxq_info) but does not call
xdp_rxq_info_unreg(). Similarly, virtnet_restore() sets up the
receive_queue again but does not call xdp_rxq_info_reg().

Actually, parts of virtnet_freeze_down() and virtnet_restore_up()
are almost identical to virtnet_close() and virtnet_open(): only
the calls to xdp_rxq_info_(un)reg() are missing. This means that
we can fix this easily and avoid such problems in the future by
just calling virtnet_close()/open() from the freeze/restore handlers.

Aside from adding the missing xdp_rxq_info calls the only difference
is that the refill work is only cancelled if netif_running(). However,
this should not make any functional difference since the refill work
should only be active if the network interface is actually up.

Comment 1 Avinash Hanwate 2025-02-27 07:56:27 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022626-CVE-2022-49687-bcfa@gregkh/T


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