{"id":"DEBIAN-CVE-2026-98467","details":"In the Linux kernel, the following vulnerability has been resolved:  KVM: arm64: nv: Fix null ptr deref on nested wp/unmap, teardown race  Commit 7270cc9157f4 (\"KVM: arm64: nv: Handle VNCR_EL2 invalidation from MMU notifiers\") introduced VNCR_EL2 invalidation in both kvm_nested_s2_unmap() and kvm_nested_s2_wp().  However at the point of this being performed concurrent stage 2 teardown of a nested guest can cause kvm-\u003earch.mmu.pgt to be set to NULL.  This happens in kvm_flush_shadow_all() -\u003e kvm_arch_flush_shadow_all() -\u003e kvm_free_stage2_pgd() and is performed under the kvm-\u003emmu_lock.  Commit ec14c272408a (\"KVM: arm64: nv: Unmap/flush shadow stage 2 page tables\") introduced the teardown of the entire nested MMU range, which then invokes stage2_apply_range() with resched=true:  mmu_notifier_invalidate_range_start()   -\u003e ... -\u003e kvm_mmu_notifier_invalidate_range_start()     -\u003e kvm_mmu_unmap_gfn_range()       -\u003e kvm_unmap_gfn_range()         -\u003e kvm_nested_s2_unmap()           -\u003e kvm_stage2_unmap_range()             -\u003e __unmap_stage2_range()                 -\u003e stage2_apply_range()  This means that stage2_apply_range() can drop the kvm-\u003emmu_lock and thus concurrent progress can be made in lockstep with kvm_arch_flush_shadow_all().  If kvm_arch_flush_shadow_all() advances ahead of stage2_apply_range() and completes its operation it guarantees a NULL pointer deref.  Since kvm_free_stage2_pgd() is performed under the kvm-\u003emmu_lock this will either be observed NULL or not and serialised against kvm_free_stage2_pgd().  Resolve the issue by abstracting the invalidation to a new function, kvm_invalidate_vncr_ipa_all(), and check that the pgt is non-NULL before dereferencing it.","modified":"2026-10-19T05:00:09.018909849Z","published":"2026-10-18T17:47:41.123714081Z","upstream":["CVE-2026-98467"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-98467"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"7.2.9-1"}]}],"versions":["6.12.100-1","6.12.101-1","6.12.105-1","6.12.107-1","6.12.111-1","6.12.113-1","6.12.38-1","6.12.41-1","6.12.43-1","6.12.43-1~bpo12+1","6.12.48-1","6.12.57-1","6.12.57-1~bpo12+1","6.12.63-1","6.12.63-1~bpo12+1","6.12.69-1","6.12.69-1~bpo12+1","6.12.73-1","6.12.73-1~bpo12+1","6.12.74-1","6.12.74-2","6.12.74-2~bpo12+1","6.12.85-1","6.12.85-1~bpo12+1","6.12.86-1","6.12.86-1~bpo12+1","6.12.88-1","6.12.88-1~bpo12+1","6.12.90-1","6.12.90-1~bpo12+1","6.12.90-2","6.12.90-2~bpo12+1","6.12.94-1","6.12.94-1~bpo12+1","6.12.95-1","6.12.95-1~bpo12+1","6.12.96-1","6.13.10-1~exp1","6.13.11-1~exp1","6.13.2-1~exp1","6.13.3-1~exp1","6.13.4-1~exp1","6.13.5-1~exp1","6.13.6-1~exp1","6.13.7-1~exp1","6.13.8-1~exp1","6.13.9-1~exp1","6.13~rc6-1~exp1","6.13~rc7-1~exp1","6.14.3-1~exp1","6.14.5-1~exp1","6.14.6-1~exp1","6.15-1~exp1","6.15.1-1~exp1","6.15.2-1~exp1","6.15.3-1~exp1","6.15.4-1~exp1","6.15.5-1~exp1","6.15.6-1~exp1","6.15~rc7-1~exp1","6.16-1~exp1","6.16.1-1~exp1","6.16.10-1","6.16.11-1","6.16.12-1","6.16.12-1~bpo13+1","6.16.12-2","6.16.3-1","6.16.3-1~bpo13+1","6.16.5-1","6.16.6-1","6.16.7-1","6.16.8-1","6.16.9-1","6.16~rc7-1~exp1","6.17.10-1","6.17.11-1","6.17.12-1","6.17.13-1","6.17.13-1~bpo13+1","6.17.2-1~exp1","6.17.5-1~exp1","6.17.6-1","6.17.7-1","6.17.7-2","6.17.8-1","6.17.8-1~bpo13+1","6.17.9-1","6.18.1-1~exp1","6.18.10-1","6.18.12-1","6.18.12-1~bpo13+1","6.18.13-1","6.18.14-1","6.18.15-1","6.18.15-1~bpo13+1","6.18.2-1~exp1","6.18.3-1","6.18.5-1","6.18.5-1~bpo13+1","6.18.8-1","6.18.9-1","6.18.9-1~bpo13+1","6.18~rc4-1~exp1","6.18~rc4-1~exp2","6.18~rc5-1~exp1","6.18~rc6-1~exp1","6.18~rc7-1~exp1","6.19-1~exp1","6.19.10-1","6.19.10-1~bpo13+1","6.19.11-1","6.19.11-1~bpo13+1","6.19.12-1","6.19.13-1","6.19.13-1~bpo13+1","6.19.14-1","6.19.14-1~bpo13+1","6.19.2-1~exp1","6.19.3-1~exp1","6.19.4-1~exp1","6.19.5-1~exp1","6.19.6-1","6.19.6-2","6.19.6-2~bpo13+1","6.19.8-1","6.19.8-1~bpo13+1","6.19~rc4-1~exp1","6.19~rc5-1~exp1","6.19~rc6-1~exp1","6.19~rc7-1~exp1","6.19~rc8-1~exp1","7.0-1~exp1","7.0.1-1~exp1","7.0.10-1","7.0.10-1~bpo13+1","7.0.12-1","7.0.12-2","7.0.12-2~bpo13+1","7.0.13-1","7.0.13-1~bpo13+1","7.0.14-1","7.0.3-1","7.0.4-1","7.0.4-1~bpo13+1","7.0.7-1","7.0.7-1~bpo13+1","7.0.9-1","7.0.9-1~bpo13+1","7.1.1-1~exp1","7.1.10-1","7.1.12-1","7.1.13-1","7.1.13-1~bpo13+1","7.1.2-1~exp1","7.1.3-1","7.1.3-1+sunvdc","7.1.3-1~bpo13+1","7.1.4-1","7.1.5-1","7.1.6-1","7.1.7-1","7.1.7-1~bpo13+1","7.1.8-1","7.1.8-1~bpo13+1","7.1.8-2","7.1.9-1","7.1.9-1+sparc64","7.1~rc2-1~exp1","7.1~rc3-1~exp1","7.1~rc4-1~exp1","7.1~rc4-1~exp2","7.1~rc5-1~exp1","7.1~rc7-1~exp1","7.2.2-1~exp1","7.2.3-1~exp1","7.2.6-1","7.2.6-1~bpo13+1","7.2.7-1","7.2.8-1","7.2.9-1~bpo13+1","7.2~rc3-1~exp1","7.2~rc5-1~exp1","7.2~rc7-1~exp1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-98467.json"}}],"schema_version":"1.9.0"}