| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49932: KVM: VMX: Do _all_ initialization before exposing /dev/kvm to userspace |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| KVM: VMX: Do _all_ initialization before exposing /dev/kvm to userspace |
| |
| Call kvm_init() only after _all_ setup is complete, as kvm_init() exposes |
| /dev/kvm to userspace and thus allows userspace to create VMs (and call |
| other ioctls). E.g. KVM will encounter a NULL pointer when attempting to |
| add a vCPU to the per-CPU loaded_vmcss_on_cpu list if userspace is able to |
| create a VM before vmx_init() configures said list. |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000008 |
| #PF: supervisor write access in kernel mode |
| #PF: error_code(0x0002) - not-present page |
| PGD 0 P4D 0 |
| Oops: 0002 [#1] SMP |
| CPU: 6 PID: 1143 Comm: stable Not tainted 6.0.0-rc7+ #988 |
| Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 |
| RIP: 0010:vmx_vcpu_load_vmcs+0x68/0x230 [kvm_intel] |
| <TASK> |
| vmx_vcpu_load+0x16/0x60 [kvm_intel] |
| kvm_arch_vcpu_load+0x32/0x1f0 [kvm] |
| vcpu_load+0x2f/0x40 [kvm] |
| kvm_arch_vcpu_create+0x231/0x310 [kvm] |
| kvm_vm_ioctl+0x79f/0xe10 [kvm] |
| ? handle_mm_fault+0xb1/0x220 |
| __x64_sys_ioctl+0x80/0xb0 |
| do_syscall_64+0x2b/0x50 |
| entry_SYSCALL_64_after_hwframe+0x46/0xb0 |
| RIP: 0033:0x7f5a6b05743b |
| </TASK> |
| Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel(+) kvm irqbypass |
| |
| The Linux kernel CVE team has assigned CVE-2022-49932 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 6.1.20 with commit e136e969d268b9b89329c816c002e53f60e82985 |
| Fixed in 6.2.7 with commit e28533c08023c4b319b7f2cd77f3f7c9204eb517 |
| Fixed in 6.3 with commit e32b120071ea114efc0b4ddd439547750b85f618 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2022-49932 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| arch/x86/kvm/vmx/vmx.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/e136e969d268b9b89329c816c002e53f60e82985 |
| https://git.kernel.org/stable/c/e28533c08023c4b319b7f2cd77f3f7c9204eb517 |
| https://git.kernel.org/stable/c/e32b120071ea114efc0b4ddd439547750b85f618 |
