DEBIAN-CVE-2026-80726

In the Linux kernel, the following vulnerability has been resolved:  KVM: x86/mmu: WARN and clear role.invalid when creating a child shadow page  Explicitly clear role.invalid when deriving a child shadow page's role from its parent to harden against bugs elsewhere in KVM, as violating KVM's invariant that invalid pages are NOT on the list of active MMU pages leads to use-after-free due to kvmmmupreparezappage() using listadd() instead of listmove() when processing an invalid shadow page, i.e. makes a bad situation far worse.  Yell loudly if the parent is invalid, as it means KVM has missed a validity check, i.e. KVM is attempting to map memory using an invalid/obsolete root, but continue on as the child is otherwise still a valid shadow page.    ==================================================================   BUG: KASAN: slab-use-after-free in kvmmmugetshadowpage+0x1817/0x1860 [kvm]   Write of size 8 at addr ff11000153dd1368 by task repro/853    CPU: 1 UID: 1000 PID: 853 Comm: repro Not tainted 7.2.0-rc2-3aec122bdcaf-next-vm #5 PREEMPT   Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015   Call Trace:    <TASK>    dumpstacklvl+0x4b/0x70    printreport+0x153/0x49c    kasanreport+0xbc/0xf0    kvmmmugetshadowpage+0x1817/0x1860 [kvm]    mmuallocroot+0x141/0x320 [kvm]    kvmmmuload+0x612/0x20f0 [kvm]    kvmarchvcpuioctlrun+0x3dd5/0x6150 [kvm]    kvmvcpuioctl+0x5e4/0x10d0 [kvm]    x64sysioctl+0x131/0x1b0    dosyscall64+0x67/0x5f0    entrySYSCALL64afterhwframe+0x4b/0x53    </TASK>    Allocated by task 853:    kasansavestack+0x20/0x40    kasansavetrack+0x14/0x30    kasanslaballoc+0x5f/0x70    kmemcacheallocnoprof+0xfe/0x2e0    kvmmmutopupmemorycache+0x135/0x530 [kvm]    paging64pagefault+0x318/0x1e30 [kvm]    kvmmmudopagefault+0x21d/0x630 [kvm]    kvmmmupagefault+0x18c/0x17b0 [kvm]    kvmarchvcpuioctlrun+0x1f35/0x6150 [kvm]    kvmvcpuioctl+0x5e4/0x10d0 [kvm]    x64sysioctl+0x131/0x1b0    dosyscall64+0x67/0x5f0    entrySYSCALL64afterhwframe+0x4b/0x53    Freed by task 853:    kasansavestack+0x20/0x40    kasansavetrack+0x14/0x30    kasansavefreeinfo+0x3b/0x60    kasanslabfree+0x43/0x70    kmemcachefree+0xe2/0x400    kvmmmucommitzappage.part.0+0x1e2/0x310 [kvm]    kvmmmufreeroots+0x283/0x560 [kvm]    kvmarchvcpuioctlrun+0x33c8/0x6150 [kvm]    kvmvcpuioctl+0x5e4/0x10d0 [kvm]    _x64sysioctl+0x131/0x1b0    dosyscall64+0x67/0x5f0    entrySYSCALL64after_hwframe+0x4b/0x53