CVE-2026-89923

CVE CVE-2026-89923EUVD EUVD-2026-80523Published 2026-09-16T10:32:16.000Z

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Free guest debug data on vcpu destroy kvm_s390_clear_bp_data() is only called from kvm_arch_vcpu_ioctl_set_guest_debug(), i.e. when user space changes or disables debugging. A vCPU that is destroyed while hardware breakpoints are still armed - the normal case when the VMM just exits or crashes - leaks hw_bp_info, hw_wp_info and all old_data buffers, since generic KVM frees the vCPU right after kvm_arch_vcpu_destroy(). That is bounded by MAX_BP_COUNT entries, so roughly 8 KiB per vCPU, but it is unbounded over VM lifetimes. The allocations are GFP_KERNEL_ACCOUNT, so the charge also outlives the exiting process and pins dying memcgs. Fix by clearing the debug data on vCPU destruction. Calling it unconditionally is fine: struct kvm_vcpu is zero allocated, so for a vCPU that never enabled debugging the counters are 0 and the pointers NULL.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Linux — Linux patch: 7.2.5; 27291e2165b6de70c476b7b675308113edd69a60 <e7f698b09d4a7c36b299acf680fc50fe868e2bcd; patch: 5.15.221; patch: 6.1.188; 27291e2165b6de70c476b7b675308113edd69a60 <b5acacfdb8966abff91836c1c5bd7da59d8a526e; 27291e2165b6de70c476b7b675308113edd69a60 <053f2068cf9b0654b651fed5ad7649d3deb982bf; patch: 5.10.270; 27291e2165b6de70c476b7b675308113edd69a60 <d6280fc540d8f4653c9b54a78cb747e128070f5e; 27291e2165b6de70c476b7b675308113edd69a60 <e4d8b7f176b976474e0800ba71ee2dfa3ce263c9; patch: 6.6.157; 27291e2165b6de70c476b7b675308113edd69a60 <9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63; patch: 7.3-rc1; patch: 0; 3.16; 27291e2165b6de70c476b7b675308113edd69a60 <6c996b12bbe4a6023076e8eee3cfaf2cc99db76c; patch: 6.18.51; 27291e2165b6de70c476b7b675308113edd69a60 <544a5a665019cef394ce8bda97fa7a2cab253781; patch: 6.12.110

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

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Linux — Linux

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