Preventing Userspace from Exploiting a VMOVP on a Dying VPE
CVE-2024-50192
What is CVE-2024-50192?
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.
Affected Version(s)
Linux 64edfaa9a2342a3ce34f8cb982c2c2df84db4de3
Linux 64edfaa9a2342a3ce34f8cb982c2c2df84db4de3 < 755b9532c885b8761fb135fedcd705e21e61cccb
Linux 64edfaa9a2342a3ce34f8cb982c2c2df84db4de3 < 64b12b061c5488e2d69e67c4eaae5da64fd30bfe