In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v4: Don't allow a VMOVP on a dying VPE Kunkun Jiang reported that there is a small window of opportunity for userspace to force a change of affinity for a VPE while the VPE has already been unmapped, but the corresponding doorbell interrupt still visible in /proc/irq/. Plug the race by checking the value of vmapp_count, which tracks whether the VPE is mapped ot not, and returning an error in this case. This involves making vmapp_count common to both GICv4.1 and its v4.0 ancestor.
https://git.kernel.org/stable/c/d960505a869e66184fff97fb334980a5b797c7c6
https://git.kernel.org/stable/c/b7d7b7fc876f836f40bf48a87e07ea18756ba196
https://git.kernel.org/stable/c/755b9532c885b8761fb135fedcd705e21e61cccb
https://git.kernel.org/stable/c/64b12b061c5488e2d69e67c4eaae5da64fd30bfe
https://git.kernel.org/stable/c/1442ee0011983f0c5c4b92380e6853afb513841a
https://git.kernel.org/stable/c/01282ab5182f85e42234df2ff42f0ce790f465ff