KVM: s390: Fix old_data leak in guest debug error path

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix old_data leak in guest debug error path __import_wp_info() allocates a per-watchpoint old_data buffer to back up the original guest memory contents. If a later watchpoint of the same KVM_SET_GUEST_DEBUG request fails to import, kvm_s390_import_bp_data() jumps to the error label, which frees the wp_info array but not the old_data buffers of the entries that were imported successfully. Up to MAX_BP_COUNT - 1 buffers of up to MAX_WP_SIZE bytes are leaked per failed request, and the request can be repeated. Create error handling for cleaning up all created old_data memory areas.

Timeline

1. Sep 16, 2026, 10:32 AM UTCCVE published
2. Oct 19, 2026, 8:54 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in 124c81ee610e1fbdd93d4399f88d9e28ba97a941; From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in e5ae7816e5ad145618f7fd568a0e8a94dd9f81f4; From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in c85d402553987777cc4742751437ea5dcbf98a7b; From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in 5fbf319137735252eefa507193c9a619af5b7457; From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in 4048d0a252163084794be3e37995b872c5178913; From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in f55e4d415d95342d5753e528e05a1e8623992c3f; From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in 46cb8a273e2f853f89a78b59dbdff8787b6e1c86; From 27291e2165b6de70c476b7b675308113edd69a60 · fixed in aa9c8e8baf1e765fa65b93212522c636f25d846f

• Linux Linux

  3.16

• KernelLinux

  From 3.16.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.51; From 6.19.0 · fixed in 7.2.5

References 8