CVE-2026-72288

Summary

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: vgic: Handle race between interrupt affinity change and LPI disabling

Hyunwoo Kim reports some really bad races should the following situation occur:

  • LPI-I is pending in vcpu-B's AP list
  • vcpu-A writes to vcpu-B's RD to disable its LPIs
  • vcpu-C moves I from B to C

If the last two race nicely enough, vgic_prune_ap_list() can drop the irq and AP list locks, reacquire them, and in the interval the irq has been freed. UAF follows.

The fix is two-fold:

  • Before dropping the irq and ap_list locks, take a reference on the irq

  • Do not try to handle migration of the pending bit: there is no expectation that this state is retained, as per the architecture

With that, we're sure that the interrupt is still around, and we safely remove it from the AP list as it has no target at this stage (unless another interrupt fires, but that's another story).

Affected Software

VendorProductVersion RangeStatus
LinuxLinux5dd4b924e390af426e424d5e52c1b4d1566af817 < d19dca8194ebed371e624331c6be2cb73b562cafaffected
LinuxLinux5dd4b924e390af426e424d5e52c1b4d1566af817 < b1a89d12d35a8256d2b170ced0b1c86851f3def2affected
LinuxLinux5dd4b924e390af426e424d5e52c1b4d1566af817 < 7258770e5814f15e8308ebda82ac9acf6964ba8eaffected
LinuxLinux4.8affected
LinuxLinux0 < 4.8unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References