CVE-2023-53319

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

KVM: arm64: Handle kvmarminit failure correctly in finalize_pkvm

Currently there is no synchronisation between finalizepkvm() and kvmarminit() initcalls. The finalizepkvm() proceeds happily even if kvmarminit() fails resulting in the following warning on all the CPUs and eventually a HYP panic:

| kvm [1]: IPA Size Limit: 48 bits | kvm [1]: Failed to init hyp memory protection | kvm [1]: error initializing Hyp mode: -22 | | <snip> | | WARNING: CPU: 0 PID: 0 at arch/arm64/kvm/pkvm.c:226 kvmhostprotfinalize+0x30/0x50 | Modules linked in: | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0 #237 | Hardware name: FVP Base RevC (DT) | pstate: 634020c5 (nZCv daIF +PAN -UAO +TCO +DIT -SSBS BTYPE=--) | pc : kvmhostprotfinalize+0x30/0x50 | lr : flushsmpcallfunctionqueue+0xd8/0x230 | | Call trace: | kvmhostprotfinalize+0x3c/0x50 | oneachcpucondmask+0x3c/0x6c | pkvmdrophostprivileges+0x4c/0x78 | finalizepkvm+0x3c/0x5c | dooneinitcall+0xcc/0x240 | doinitcalllevel+0x8c/0xac | doinitcalls+0x54/0x94 | dobasicsetup+0x1c/0x28 | kernelinitfreeable+0x100/0x16c | kernelinit+0x20/0x1a0 | retfromfork+0x10/0x20 | Failed to finalize Hyp protection: -22 | dtb=fvp-base-revc.dtb | kvm [95]: nVHE hyp BUG at: arch/arm64/kvm/hyp/nvhe/memprotect.c:540! | kvm [95]: nVHE call trace: | kvm [95]: [<ffff800081052984>] _kvmnvhehyppanic+0xac/0xf8 | kvm [95]: [<ffff800081059644>] _kvmnvhehandlehostmemabort+0x1a0/0x2ac | kvm [95]: [<ffff80008105511c>] _kvmnvhehandletrap+0x4c/0x160 | kvm [95]: [<ffff8000810540fc>] _kvmnvheskippauthsave+0x4/0x4 | kvm [95]: ---[ end nVHE call trace ]--- | kvm [95]: Hyp Offset: 0xfffe8db00ffa0000 | Kernel panic - not syncing: HYP panic: | PS:a34023c9 PC:0000f250710b973c ESR:00000000f2000800 | FAR:ffff000800cb00d0 HPFAR:000000000880cb00 PAR:0000000000000000 | VCPU:0000000000000000 | CPU: 3 PID: 95 Comm: kworker/u16:2 Tainted: G W 6.4.0 #237 | Hardware name: FVP Base RevC (DT) | Workqueue: rpciod rpcasyncschedule | Call trace: | dumpbacktrace+0xec/0x108 | showstack+0x18/0x2c | dumpstacklvl+0x50/0x68 | dumpstack+0x18/0x24 | panic+0x138/0x33c | nvhehyppanichandler+0x100/0x184 | newslab+0x23c/0x54c | _slaballoc+0x3e4/0x770 | kmemcacheallocnode+0x1f0/0x278 | _allocskb+0xdc/0x294 | tcpstreamallocskb+0x2c/0xf0 | tcpsendmsglocked+0x3d0/0xda4 | tcpsendmsg+0x38/0x5c | inetsendmsg+0x44/0x60 | socksendmsg+0x1c/0x34 | xprtsocksendmsg+0xdc/0x274 | xstcpsendrequest+0x1ac/0x28c | xprttransmit+0xcc/0x300 | calltransmit+0x78/0x90 | _rpcexecute+0x114/0x3d8 | rpcasyncschedule+0x28/0x48 | processonework+0x1d8/0x314 | workerthread+0x248/0x474 | kthread+0xfc/0x184 | retfromfork+0x10/0x20 | SMP: stopping secondary CPUs | Kernel Offset: 0x57c5cb460000 from 0xffff800080000000 | PHYSOFFSET: 0x80000000 | CPU features: 0x00000000,1035b7a3,ccfe773f | Memory Limit: none | ---[ end Kernel panic - not syncing: HYP panic: | PS:a34023c9 PC:0000f250710b973c ESR:00000000f2000800 | FAR:ffff000800cb00d0 HPFAR:000000000880cb00 PAR:0000000000000000 | VCPU:0000000000000000 ]---

Fix it by checking for the successfull initialisation of kvmarminit() in finalize_pkvm() before proceeding any futher.