cbcvebase.
CVE-2024-40953
published 2024-07-12

CVE-2024-40953: In the Linux kernel, the following vulnerability has been resolved: KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() Use {READ,WRITE}_ONCE() to…

PriorityP417medium4.7CVSS 3.1
AVLACHPRLUINSUCNINAH
EPSS
0.20%
9.7th percentile
In the Linux kernel, the following vulnerability has been resolved: KVM: Fix a data race on last_boosted_vcpu in kvm_vcpu_on_spin() Use {READ,WRITE}_ONCE() to access kvm->last_boosted_vcpu to ensure the loads and stores are atomic. In the extremely unlikely scenario the compiler tears the stores, it's theoretically possible for KVM to attempt to get a vCPU using an out-of-bounds index, e.g. if the write is split into multiple 8-bit stores, and is paired with a 32-bit load on a VM with 257 vCPUs: CPU0 CPU1 last_boosted_vcpu = 0xff; (last_boosted_vcpu = 0x100) last_boosted_vcpu[15:8] = 0x01; i = (last_boosted_vcpu = 0x1ff) last_boosted_vcpu[7:0] = 0x00; vcpu = kvm->vcpu_array[0x1ff]; As detected by KCSAN: BUG: KCSAN: data-race in kvm_vcpu_on_spin [kvm] / kvm_vcpu_on_spin [kvm] write to 0xffffc90025a92344 of 4 bytes by task 4340 on cpu 16: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4112) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64_sys_ioctl (fs/ioctl.c:890) x64_sys_call (arch/x86/entry/syscall_64.c:33) do_syscall_64 (arch/x86/entry/common.c:?) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) read to 0xffffc90025a92344 of 4 bytes by task 4342 on cpu 4: kvm_vcpu_on_spin (arch/x86/kvm/../../../virt/kvm/kvm_main.c:4069) kvm handle_pause (arch/x86/kvm/vmx/vmx.c:5929) kvm_intel vmx_handle_exit (arch/x86/kvm/vmx/vmx.c:? arch/x86/kvm/vmx/vmx.c:6606) kvm_intel vcpu_run (arch/x86/kvm/x86.c:11107 arch/x86/kvm/x86.c:11211) kvm kvm_arch_vcpu_ioctl_run (arch/x86/kvm/x86.c:?) kvm kvm_vcpu_ioctl (arch/x86/kvm/../../../virt/kvm/kvm_main.c:?) kvm __se_sys_ioctl (fs/ioctl.c:52 fs/ioctl.c:904 fs/ioctl.c:890) __x64

Affected

29 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.99-1 (bookworm)linux 6.1.99-1 (bookworm)
debianlinux-6.1< linux 6.1.99-1 (bookworm)linux 6.1.99-1 (bookworm)
linuxlinux
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < 11a772d5376aa6d3e2e69b5b5c585f79b60c0e1711a772d5376aa6d3e2e69b5b5c585f79b60c0e17
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < 4c141136a28421b78f34969b25a4fa32e06e21804c141136a28421b78f34969b25a4fa32e06e2180
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < 71fbc3af3dacb26c3aa2f30bb3ab05c44d082c8471fbc3af3dacb26c3aa2f30bb3ab05c44d082c84
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < 82bd728a06e55f5b5f93d10ce67f4fe7e689853a82bd728a06e55f5b5f93d10ce67f4fe7e689853a
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < 92c77807d938145c7c3350c944ef9f39d7f6017c92c77807d938145c7c3350c944ef9f39d7f6017c
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < a937ef951bba72f48d2402451419d725d70dba20a937ef951bba72f48d2402451419d725d70dba20
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < 95c8dd79f3a14df96b3820b35b8399bd91b2be6095c8dd79f3a14df96b3820b35b8399bd91b2be60
linuxlinux>= 217ece6129f2d3b4fdd18d9e79be9e43d8d14a42 < 49f683b41f28918df3e51ddc0d928cb2e934ccdb49f683b41f28918df3e51ddc0d928cb2e934ccdb
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel
linuxlinux_kernel>= 0 < 5.10.234-15.10.234-1
linuxlinux_kernel>= 0 < 6.1.99-16.1.99-1
linuxlinux_kernel>= 0 < 6.9.7-16.9.7-1
linuxlinux_kernel>= 0 < 6.9.7-16.9.7-1
linuxlinux_kernel>= 0 < 5.4.0-208.2285.4.0-208.228
linuxlinux_kernel>= 0 < 5.15.0-133.1445.15.0-133.144
linuxlinux_kernel>= 0 < 6.8.0-44.446.8.0-44.44
linuxlinux_kernel>= 2.6.39 < 4.19.3234.19.323
linuxlinux_kernel>= 4.20 < 5.4.2855.4.285
linuxlinux_kernel>= 5.11 < 5.15.1695.15.169

CVSS provenance

nvdv3.14.7MEDIUMCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_ubuntu7.8HIGH
vendor_debian4.7MEDIUM
vendor_redhat4.7MEDIUM
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