CVE-2026-52968
HighCVSS 7.1Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
In the Linux kernel, a vulnerability in the KVM subsystem for s390 architecture involves double-scaling pointer arithmetic when indexing the GAIT table. Functions kvm_s390_pci_aif_enable(), kvm_s390_pci_aif_disable(), and aen_host_forward() manually multiply the index by sizeof(struct zpci_gaite), causing access to element aisb*16 instead of aisb. This leads to out-of-bounds memory access when aisb >= 32 (with ZPCI_NR_DEVICES=512).
Risk Assessment
The vulnerability could allow a local attacker with KVM administrator privileges to cause a kernel panic or potentially escalate privileges in the s390 virtualization environment.
Recommendation
Apply the Linux kernel patch that removes the erroneous sizeof(struct zpci_gaite) multiplication in kvm_s390_pci_aif_enable(), kvm_s390_pci_aif_disable(), and aen_host_forward(). Update to a kernel version containing the fix.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: KVM: s390: pci: fix GAIT table indexing due to double-scaling pointer arithmetic kvm_s390_pci_aif_enable(), kvm_s390_pci_aif_disable(), and aen_host_forward() index the GAIT by manually multiplying the index with sizeof(struct zpci_gaite). Since aift->gait is already a struct zpci_gaite pointer, this double-scales the offset, accessing element aisb*16 instead of aisb. This causes out-of-bounds accesses when aisb >= 32 (with ZPCI_NR_DEVICES=512) Fix by removing the erroneous sizeof multiplication.