UBUNTU-CVE-2026-31695: Use After Free

Published May 1, 2026

In the Linux kernel, the following vulnerability has been resolved: wifi: virtwifi: remove SETNETDEVDEV to avoid use-after-free Currently we execute SETNETDEVDEV(dev, &priv->lowerdev->dev) for the virtwifi net devices. However, unregistering a virtwifi device in netdevruntodo() can happen together with the device referenced by SETNETDEVDEV(). It can result in use-after-free during the ethtool operations performed on a virtwifi device that is currently being unregistered. Such a net device can have the dev.parent field pointing to the freed memory, but ethnlopsbegin() calls pmruntimegetsync(dev->dev.parent). Let's remove SETNETDEVDEV for virtwifi to avoid bugs like this: ================================================================== BUG: KASAN: slab-use-after-free in pmruntimeresume+0xe2/0xf0 Read of size 2 at addr ffff88810cfc46f8 by task pm/606 Call Trace: <TASK> dumpstacklvl+0x4d/0x70 printreport+0x170/0x4f3 ? pfxrawspinlockirqsave+0x10/0x10 kasanreport+0xda/0x110 ? pmruntimeresume+0xe2/0xf0 ? pmruntimeresume+0xe2/0xf0 pmruntimeresume+0xe2/0xf0 ethnlopsbegin+0x49/0x270 ethnlsetfeatures+0x23c/0xab0 ? pfxethnlsetfeatures+0x10/0x10 ? kvmschedclockread+0x11/0x20 ? localclocknoinstr+0xf/0xf0 ? localclock+0x10/0x30 ? kasansavetrack+0x25/0x60 ? kasankmalloc+0x7f/0x90 ? genlfamilyrcvmsgattrsparse.isra.0+0x150/0x2c0 genlfamilyrcvmsgdoit+0x1e7/0x2c0 ? pfxgenlfamilyrcvmsgdoit+0x10/0x10 ? pfxcredhascapability.isra.0+0x10/0x10 ? stacktracesave+0x8e/0xc0 genlrcvmsg+0x411/0x660 ? pfxgenlrcvmsg+0x10/0x10 ? pfxethnlsetfeatures+0x10/0x10 netlinkrcvskb+0x121/0x380 ? pfxgenlrcvmsg+0x10/0x10 ? pfxnetlinkrcvskb+0x10/0x10 ? pfxdownread+0x10/0x10 genlrcv+0x23/0x30 netlinkunicast+0x60f/0x830 ? pfxnetlinkunicast+0x10/0x10 ? pfxallocskb+0x10/0x10 netlinksendmsg+0x6ea/0xbc0 ? pfxnetlinksendmsg+0x10/0x10 ? futexqueue+0x10b/0x1f0 syssendmsg+0x7a2/0x950 ? copymsghdrfromuser+0x26b/0x430 ? pfxsyssendmsg+0x10/0x10 ? pfxcopymsghdrfromuser+0x10/0x10 syssendmsg+0xf8/0x180 ? pfxsyssendmsg+0x10/0x10 ? pfxfutexwait+0x10/0x10 ? fdget+0x2e4/0x4a0 syssendmsg+0x11f/0x1c0 ? pfxsyssendmsg+0x10/0x10 dosyscall64+0xe2/0x570 ? excpagefault+0x66/0xb0 entrySYSCALL64afterhwframe+0x77/0x7f </TASK> This fix may be combined with another one in the ethtool subsystem: https://lore.kernel.org/all/20260322075917.254874-1-alex.popov@linux.com/T/#u

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.119~20.04.1
  2. Upgrade

    Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.126~20.04.1
  3. Upgrade

    Upgrade ubuntu/linux-azure-fde-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.126~20.04.2
  4. Upgrade

    Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.122~20.04.1
  5. Upgrade

    Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-186.196~20.04.1
  6. Upgrade

    Upgrade ubuntu/linux-ibm-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1106.110~20.04.1
  7. Upgrade

    Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1107.113~20.04.1
  8. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-184.194~20.04.1
  9. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1064.66~20.04.1
  10. Upgrade

    Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1109.115~20.04.1
  11. Upgrade

    Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.

    Fixed in 5.15.0-1106.110~20.04.1
  12. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 5.15.0-186.196
  13. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.119
  14. Upgrade

    Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1061.64~22.04.1
  15. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.126
  16. Upgrade

    Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1063.71~22.04.1
  17. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.126
  18. Upgrade

    Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1062.69~22.04.1
  19. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.122
  20. Upgrade

    Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.72~22.04.1
  21. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 5.15.0-1108.114
  22. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 5.15.0-1095.103
  23. Upgrade

    Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-136.136~22.04.1
  24. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1106.110
  25. Upgrade

    Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1061.62~22.04.1
  26. Upgrade

    Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.

    Fixed in 5.15.0-1107.113
  27. Upgrade

    Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.

    Fixed in 5.15.0-1104.109
  28. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 5.15.0-184.194
  29. Upgrade

    Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-136.136.2~22.04.1
  30. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 5.15.0-1107.108
  31. Upgrade

    Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1059.62~22.04.1
  32. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 5.15.0-1064.66
  33. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra-igx to a version that resolves this vulnerability.

    Fixed in 5.15.0-1053.53
  34. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 5.15.0-1109.115
  35. Upgrade

    Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-1058.61~22.04.1
  36. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 5.15.0-1106.109
  37. Upgrade

    Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.0-136.136~22.04.3
  38. Upgrade

    Upgrade ubuntu/linux-xilinx-zynqmp to a version that resolves this vulnerability.

    Fixed in 5.15.0-1075.79
  39. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 5.15.0-1096.98
  40. Upgrade

    Upgrade ubuntu/linux-intel-iot-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1104.106
  41. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 5.15.0-1111.120
  42. Upgrade

    Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.

    Fixed in 6.8.1-1056.57~22.04.2
  43. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.119+fips1
  44. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1117.126+fips1
  45. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-186.196+fips1
  46. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 5.15.0-1112.122+fips1
  47. Upgrade

    Upgrade ubuntu/linux to a version that resolves this vulnerability.

    Fixed in 6.8.0-136.136
  48. Upgrade

    Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.

    Fixed in 6.8.0-1061.64
  49. Upgrade

    Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.

    Fixed in 6.8.0-1063.71
  50. Upgrade

    Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.

    Fixed in 6.8.0-1062.69
  51. Upgrade

    Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.72
  52. Upgrade

    Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.

    Fixed in 6.8.0-1059.67
  53. Upgrade

    Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.

    Fixed in 6.8.0-1046.50
  54. Upgrade

    Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.

    Fixed in 6.8.0-1061.62
  55. Upgrade

    Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-136.136.2
  56. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 6.8.0-1059.62
  57. Upgrade

    Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.

    Fixed in 6.8.0-1059.62.1
  58. Upgrade

    Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.

    Fixed in 6.8.0-1030.31
  59. Upgrade

    Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.

    Fixed in 6.8.0-1058.61
  60. Upgrade

    Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.

    Fixed in 6.8.0-1061.65
  61. Upgrade

    Upgrade ubuntu/linux-vmware to a version that resolves this vulnerability.

    Fixed in 6.8.0-1008.8
  62. Upgrade

    Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.

    Fixed in 6.8.0-1033.34
  63. Upgrade

    Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.

    Fixed in 6.8.0-1028.33
  64. Upgrade

    Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.0-2050.52
  65. Upgrade

    Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.

    Fixed in 6.8.1-1056.57
  66. Upgrade

    Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1061.64+fips1
  67. Upgrade

    Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1063.71+fips2
  68. Upgrade

    Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-136.136+fips2
  69. Upgrade

    Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.

    Fixed in 6.8.0-1064.72+fips1
  70. Upgrade

    Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.

    Fixed in 7.0.0-1006.6
  71. Configuration

    Remove the SET_NETDEV_DEV(dev, &priv->lowerdev->dev) call for virt_wifi net devices to prevent dev.parent from referencing freed memory during unregistration.

    Linux kernel virt_wifi SET_NETDEV_DEV = removed

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