CVE-2022-49687

Summary

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.

Impact & exploitability

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products we track (1)

Recommendation

Apply the vendor fix promptly. Open any affected product above for its exact safe version.

Official patch: https://git.kernel.org/stable/c/340fbdc8011f2dc678f622c5ce1cbb5ab8305de7 ↗

Additional information

• NVD record
• https://git.kernel.org/stable/c/340fbdc8011f2dc678f622c5ce1cbb5ab8305de7Patch
• https://git.kernel.org/stable/c/57ee40f1b198b59d43c216fbc4672f9300d3c8b0Patch
• https://git.kernel.org/stable/c/8af52fe9fd3bf5e7478da99193c0632276e1dfcePatch
• https://git.kernel.org/stable/c/8c7a32b7c15555beddc5810c3334d9cefff061bfPatch
• https://git.kernel.org/stable/c/8d7fe9ad6fddc2af8bde4b921b4f8fab231ed38cPatch
• https://git.kernel.org/stable/c/9222672fa6370f0ec3d899662cb8680e9282fc4cPatch