Answer in brief
CVE-2026-89923 records a Unknown severity vulnerability in KVM: s390: Free guest debug data on vcpu destroy. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=27291e2165b6de70c476b7b675308113edd69a60 <053f2068cf9b0654b651fed5ad7649d3deb982bf || >=27291e2165b6de70c476b7b675308113edd69a60 <6c996b12bbe4a6023076e8eee3cfaf2cc99db76c || >=27291e2165b6de70c476b7b675308113edd69a60 <d6280fc540d8f4653c9b54a78cb747e128070f5e || >=27291e2165b6de70c476b7b675308113edd69a60 <544a5a665019cef394ce8bda97fa7a2cab253781 || >=27291e2165b6de70c476b7b675308113edd69a60 <9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63 || >=27291e2165b6de70c476b7b675308113edd69a60 <b5acacfdb8966abff91836c1c5bd7da59d8a526e || >=27291e2165b6de70c476b7b675308113edd69a60 <e4d8b7f176b976474e0800ba71ee2dfa3ce263c9 || >=27291e2165b6de70c476b7b675308113edd69a60 <e7f698b09d4a7c36b299acf680fc50fe868e2bcd | 053f2068cf9b0654b651fed5ad7649d3deb982bf, 6c996b12bbe4a6023076e8eee3cfaf2cc99db76c, d6280fc540d8f4653c9b54a78cb747e128070f5e, 544a5a665019cef394ce8bda97fa7a2cab253781, 9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63, b5acacfdb8966abff91836c1c5bd7da59d8a526e, e4d8b7f176b976474e0800ba71ee2dfa3ce263c9, e7f698b09d4a7c36b299acf680fc50fe868e2bcd |
| Linux/Linuxgeneric | 3.16 | Not reported |
Published upstream
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 16, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 16, 2026
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.
Quoted source text, attributed separately from HOL analysis.