CVE-2026-100080 PUBLISHED

xen-netback: Fix UAF when reading statistics data

Assigner: Linux
Reserved: 25.09.2026 Published: 06.11.2026 Updated: 06.11.2026

In the Linux kernel, the following vulnerability has been resolved:

xen-netback: Fix UAF when reading statistics data

The network statistic data in the driver is protected by RCU. Unfortunately when tearing down the queues after an error during connecting to the frontend (e.g. due to illegal Xenstore data filled in by the guest), the statistic data is being freed without synchronizing the RCU state. In case the data is being read via sysfs in this phase, access to already freed memory or memory being in new use is possible.

Fix that by calling synchronize_net() before freeing the queue data.

This is XSA-526 / CVE-2026-100080

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 4223b33be49ee09acb6f1d26beb4a36dd3b8d63a (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to ab9cdf1291be551da999510b30216a2886074d7a (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 36f858f228e3f955b9336af7f94634747c221518 (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 89e534265b62c94749639350200b10370564bb3a (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 6cd611d2abdd8623a554e14145f82c1cb4e4467a (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 37d5a73170579b30e67cc8b19ec69715eea3a6b6 (excl.)
  • affected from 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to 4867687b6ad28ab84bc0811d8f8f9972e769da02 (excl.)
  • affected from 0 to 5.10.274 (excl.)
  • affected from 0 to 5.15.225 (excl.)
  • affected from 0 to 6.1.192 (excl.)
  • affected from 0 to 6.6.162 (excl.)
  • affected from 0 to 6.12.116 (excl.)
  • affected from 0 to 6.18.62 (excl.)
  • affected from 0 to 7.3.3 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • unaffected from 5.10.274 to 5.10.* (incl.)
  • unaffected from 5.15.225 to 5.15.* (incl.)
  • unaffected from 6.1.192 to 6.1.* (incl.)
  • unaffected from 6.6.162 to 6.6.* (incl.)
  • unaffected from 6.12.116 to 6.12.* (incl.)
  • unaffected from 6.18.62 to 6.18.* (incl.)
  • unaffected from 7.3.3 to 7.3.* (incl.)

References