CVE-2026-46316
CriticalCVSS 9.3Exploitation Probability (EPSS)
Low risk8th percentile — higher than 8% of all known CVEs
Summary
A vulnerability was found in the Linux kernel's KVM for ARM64, specifically in the VGIC-ITS translation cache. The cache invalidation function can drop the same reference multiple times when called concurrently from different contexts, leading to a premature object release.
Risk Assessment
The risk involves a potential use-after-free condition that could compromise kernel memory integrity, potentially leading to system crashes or privilege escalation in virtualized environments.
Recommendation
Immediately update the Linux kernel to a version containing the fix that ensures references are dropped only for entries actually removed from the translation cache.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: vgic-its: Drop the translation cache reference only for the erased entry vgic_its_invalidate_cache() walks the per-ITS translation cache with xa_for_each() and drops the cache's reference on each entry with vgic_put_irq(). It puts the iterated pointer, though, rather than the value returned by xa_erase(). The function is called from contexts that do not exclude one another: the ITS command handlers hold its_lock, the GITS_CTLR write path holds cmd_lock, and the path that clears EnableLPIs in a redistributor's GICR_CTLR holds neither. Two or more of them can drain the same cache concurrently, and if each one observes the same entry, erases it and then puts it, the single reference the cache holds on that entry is dropped more than once. The entry can then be freed while an ITE still maps it. xa_erase() is atomic and returns the previous entry, so put only the entry that this context actually removed. The cache reference is then dropped exactly once per entry even when the invalidations run concurrently, and the behavior is unchanged when only one context runs.