UBUNTU-CVE-2025-38407: Medium severity ubuntu/linux-hwe-edge vulnerability

Q: Which systems are most likely to be affected?

The issue affects RISC-V SMP boot configurations where NUMA is enabled and per-CPU data is placed in the vmalloc area. The provided reproduction uses a RISC-V QEMU virtual machine with two CPUs, CONFIG_NUMA=y, CONFIG_DEBUG_VIRTUAL=y, and percpu_alloc=page.

Q: What conditions trigger the boot failure?

The failure occurs when the SBI hart-start path needs a physical address for boot data but that data was allocated in vmalloc-backed per-CPU storage. This can occur on very sparse configurations when the page per-CPU allocator is selected, including when booting with percpu_alloc=page.

Q: What is the operational impact?

A newly started RISC-V hart can access an invalid address and immediately hang, preventing SMP boot from completing. The CVSS vector indicates local access and low privileges are required, with availability impact but no confidentiality or integrity impact.

Q: How can administrators identify a potentially affected boot configuration?

Check whether the system is booting a RISC-V SMP kernel with NUMA enabled and the page per-CPU allocator in use, particularly if percpu_alloc=page is present in the kernel command line. Affected boots may hang as an additional hart is started.

Published Jul 25, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved: riscv: cpuopssbi: Use static array for bootdata Since commit 6b9f29b81b15 ("riscv: Enable pcpu page first chunk allocator"), if NUMA is enabled, the page percpu allocator may be used on very sparse configurations, or when requested on boot with percpualloc=page. In that case, percpu data gets put in the vmalloc area. However, sbihsmhartstart() needs the physical address of a sbihartbootdata, and simply assumes that pa() would work. This causes the just started hart to immediately access an invalid address and hang. Fortunately, struct sbihartbootdata is not too large, so we can simply allocate an array for bootdata statically, putting it in the kernel image. This fixes NUMA=y SMP boot on Sophgo SG2042. To reproduce on QEMU: Set CONFIGNUMA=y and CONFIGDEBUGVIRTUAL=y, then run with: qemu-system-riscv64 -M virt -smp 2 -nographic \ -kernel arch/riscv/boot/Image \ -append "percpualloc=page" Kernel output: [ 0.000000] Booting Linux on hartid 0 [ 0.000000] Linux version 6.16.0-rc1 (dram@sakuya) (riscv64-unknown-linux-gnu-gcc (GCC) 14.2.1 20250322, GNU ld (GNU Binutils) 2.44) #11 SMP Tue Jun 24 14:56:22 CST 2025 ... [ 0.000000] percpu: 28 4K pages/cpu s85784 r8192 d20712 ... [ 0.083192] smp: Bringing up secondary CPUs ... [ 0.086722] ------------[ cut here ]------------ [ 0.086849] virttophys used for non-linear address: (ptrval) (0xff2000000001d080) [ 0.088001] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:14 virttophys+0xae/0xe8 [ 0.088376] Modules linked in: [ 0.088656] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.16.0-rc1 #11 NONE [ 0.088833] Hardware name: riscv-virtio,qemu (DT) [ 0.088948] epc : virttophys+0xae/0xe8 [ 0.089001] ra : virttophys+0xae/0xe8 [ 0.089037] epc : ffffffff80021eaa ra : ffffffff80021eaa sp : ff2000000004bbc0 [ 0.089057] gp : ffffffff817f49c0 tp : ff60000001d60000 t0 : 5f6f745f74726976 [ 0.089076] t1 : 0000000000000076 t2 : 705f6f745f747269 s0 : ff2000000004bbe0 [ 0.089095] s1 : ff2000000001d080 a0 : 0000000000000000 a1 : 0000000000000000 [ 0.089113] a2 : 0000000000000000 a3 : 0000000000000000 a4 : 0000000000000000 [ 0.089131] a5 : 0000000000000000 a6 : 0000000000000000 a7 : 0000000000000000 [ 0.089155] s2 : ffffffff8130dc00 s3 : 0000000000000001 s4 : 0000000000000001 [ 0.089174] s5 : ffffffff8185eff8 s6 : ff2000007f1eb000 s7 : ffffffff8002a2ec [ 0.089193] s8 : 0000000000000001 s9 : 0000000000000001 s10: 0000000000000000 [ 0.089211] s11: 0000000000000000 t3 : ffffffff8180a9f7 t4 : ffffffff8180a9f7 [ 0.089960] t5 : ffffffff8180a9f8 t6 : ff2000000004b9d8 [ 0.089984] status: 0000000200000120 badaddr: ffffffff80021eaa cause: 0000000000000003 [ 0.090101] [<ffffffff80021eaa>] virttophys+0xae/0xe8 [ 0.090228] [<ffffffff8001d796>] sbicpustart+0x6e/0xe8 [ 0.090247] [<ffffffff8001a5da>] cpuup+0x1e/0x8c [ 0.090260] [<ffffffff8002a32e>] bringupcpu+0x42/0x258 [ 0.090277] [<ffffffff8002914c>] cpuhpinvokecallback+0xe0/0x40c [ 0.090292] [<ffffffff800294e0>] cpuhpinvokecallbackrange+0x68/0xfc [ 0.090320] [<ffffffff8002a96a>] cpuup+0x11a/0x244 [ 0.090334] [<ffffffff8002aae6>] cpuup+0x52/0x90 [ 0.090384] [<ffffffff80c09350>] bringupnonbootcpus+0x78/0x118 [ 0.090411] [<ffffffff80c11060>] smpinit+0x34/0xb8 [ 0.090425] [<ffffffff80c01220>] kernelinitfreeable+0x148/0x2e4 [ 0.090442] [<ffffffff80b83802>] kernelinit+0x1e/0x14c [ 0.090455] [<ffffffff800124ca>] retfromforkkernel+0xe/0xf0 [ 0.090471] [<ffffffff80b8d9c2>] retfromforkkernelasm+0x16/0x18 [ 0.090560] ---[ end trace 0000000000000000 ]--- [ 1.179875] CPU1: failed to come online [ 1.190324] smp: Brought up 1 node, 1 CPU

Affected Software

132 affected componentsFixes available

ubuntu/linux-hwe-edge*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.8*

ubuntu/linux-intel-5.13*

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.8*

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-aws-6.8<6.8.0-1046.49~22.04.1

6.8.0-1046.49~22.04.1

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-6.8<6.8.0-1051.57~22.04.1

6.8.0-1051.57~22.04.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-azure-fde-6.8<6.8.0-1046.53~22.04.1

6.8.0-1046.53~22.04.1

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gcp-6.8<6.8.0-1047.50~22.04.2

6.8.0-1047.50~22.04.2

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-hwe-6.8<6.8.0-100.100~22.04.1

6.8.0-100.100~22.04.1

ubuntu/linux-ibm-6.8<6.8.0-1044.44~22.04.1

6.8.0-1044.44~22.04.1

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-lowlatency-hwe-6.8<6.8.0-100.100.1~22.04.1

6.8.0-100.100.1~22.04.1

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-nvidia-6.8<6.8.0-1046.49~22.04.1

6.8.0-1046.49~22.04.1

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle-6.5*

ubuntu/linux-oracle-6.8<6.8.0-1043.44~22.04.1

6.8.0-1043.44~22.04.1

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-riscv-6.8<6.8.0-100.100~22.04.1

6.8.0-100.100~22.04.1

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-realtime-6.8<6.8.1-1041.42~22.04.1

6.8.1-1041.42~22.04.1

ubuntu/linux<6.8.0-100.100

6.8.0-100.100

ubuntu/linux-aws<6.8.0-1046.49

6.8.0-1046.49

ubuntu/linux-aws-6.14<6.14.0-1015.15~24.04.1

6.14.0-1015.15~24.04.1

ubuntu/linux-azure<6.8.0-1046.52

6.8.0-1046.52

ubuntu/linux-azure-6.11*

ubuntu/linux-azure-6.14<6.14.0-1014.14~24.04.1

6.14.0-1014.14~24.04.1

ubuntu/linux-azure-fde<6.8.0-1046.53

6.8.0-1046.53

ubuntu/linux-azure-nvidia<6.8.0-1039.42

6.8.0-1039.42

ubuntu/linux-azure-nvidia-6.14<6.14.0-1007.7

6.14.0-1007.7

ubuntu/linux-gcp<6.8.0-1047.50

6.8.0-1047.50

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14<6.14.0-1018.19~24.04.1

6.14.0-1018.19~24.04.1

ubuntu/linux-gke<6.8.0-1043.48

6.8.0-1043.48

ubuntu/linux-gkeop<6.8.0-1030.33

6.8.0-1030.33

ubuntu/linux-hwe-6.11*

ubuntu/linux-ibm<6.8.0-1044.44

6.8.0-1044.44

ubuntu/linux-intel*

ubuntu/linux-lowlatency<6.8.0-100.100.1

6.8.0-100.100.1

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia<6.8.0-1046.49

6.8.0-1046.49

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-lowlatency<6.8.0-1046.49.1

6.8.0-1046.49.1

ubuntu/linux-nvidia-tegra<6.8.0-1020.20

6.8.0-1020.20

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14<6.14.0-1014.14

6.14.0-1014.14

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle<6.8.0-1043.44

6.8.0-1043.44

ubuntu/linux-oracle-6.14<6.14.0-1015.15~24.04.1

6.14.0-1015.15~24.04.1

ubuntu/linux-raspi<6.8.0-1047.51

6.8.0-1047.51

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-6.14<6.14.0-34.34.1~24.04.1

6.14.0-34.34.1~24.04.1

ubuntu/linux-xilinx<6.8.0-1023.24

6.8.0-1023.24

ubuntu/linux-bluefield<6.8.0-1016.20

6.8.0-1016.20

ubuntu/linux-raspi-realtime<6.8.0-2037.38

6.8.0-2037.38

ubuntu/linux-realtime<6.8.1-1041.42

6.8.1-1041.42

ubuntu/linux-realtime-6.14<6.14.0-1014.14~24.04.1

6.14.0-1014.14~24.04.1

ubuntu/linux-aws-fips<6.8.0-1046.49+fips1

6.8.0-1046.49+fips1

ubuntu/linux-azure-fips<6.8.0-1046.52+fips1

6.8.0-1046.52+fips1

ubuntu/linux-fips<6.8.0-100.100+fips1

6.8.0-100.100+fips1

ubuntu/linux-gcp-fips<6.8.0-1047.50+fips1

6.8.0-1047.50+fips1

ubuntu/linux-azure-fde*

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1051.57~22.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.53~22.04.1
Upgrade
Upgrade ubuntu/linux-gcp-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1047.50~22.04.2
Upgrade
Upgrade ubuntu/linux-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100~22.04.1
Upgrade
Upgrade ubuntu/linux-ibm-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1044.44~22.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100.1~22.04.1
Upgrade
Upgrade ubuntu/linux-nvidia-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49~22.04.1
Upgrade
Upgrade ubuntu/linux-oracle-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-1043.44~22.04.1
Upgrade
Upgrade ubuntu/linux-riscv-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100~22.04.1
Upgrade
Upgrade ubuntu/linux-realtime-6.8 to a version that resolves this vulnerability.
Fixed in 6.8.1-1041.42~22.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49
Upgrade
Upgrade ubuntu/linux-aws-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-1015.15~24.04.1
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.52
Upgrade
Upgrade ubuntu/linux-azure-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-1014.14~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.53
Upgrade
Upgrade ubuntu/linux-azure-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1039.42
Upgrade
Upgrade ubuntu/linux-azure-nvidia-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-1007.7
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 6.8.0-1047.50
Upgrade
Upgrade ubuntu/linux-gcp-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-1018.19~24.04.1
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 6.8.0-1043.48
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 6.8.0-1030.33
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 6.8.0-1044.44
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100.1
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49
Upgrade
Upgrade ubuntu/linux-nvidia-lowlatency to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49.1
Upgrade
Upgrade ubuntu/linux-nvidia-tegra to a version that resolves this vulnerability.
Fixed in 6.8.0-1020.20
Upgrade
Upgrade ubuntu/linux-oem-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-1014.14
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 6.8.0-1043.44
Upgrade
Upgrade ubuntu/linux-oracle-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-1015.15~24.04.1
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 6.8.0-1047.51
Upgrade
Upgrade ubuntu/linux-riscv-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-34.34.1~24.04.1
Upgrade
Upgrade ubuntu/linux-xilinx to a version that resolves this vulnerability.
Fixed in 6.8.0-1023.24
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 6.8.0-1016.20
Upgrade
Upgrade ubuntu/linux-raspi-realtime to a version that resolves this vulnerability.
Fixed in 6.8.0-2037.38
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 6.8.1-1041.42
Upgrade
Upgrade ubuntu/linux-realtime-6.14 to a version that resolves this vulnerability.
Fixed in 6.14.0-1014.14~24.04.1
Upgrade
Upgrade ubuntu/linux-aws-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.49+fips1
Upgrade
Upgrade ubuntu/linux-azure-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-1046.52+fips1
Upgrade
Upgrade ubuntu/linux-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-100.100+fips1
Upgrade
Upgrade ubuntu/linux-gcp-fips to a version that resolves this vulnerability.
Fixed in 6.8.0-1047.50+fips1
Compensating control
In the RISC-V SBI CPU operations code, use a statically allocated array for sbi_hart_boot_data in the kernel image instead of percpu data, ensuring sbi_hsm_hart_start receives a valid physical address when NUMA=y or percpu_alloc=page is used.

Event History

Jul 25, 2025

CVE Published

via OSV·02:15 PM

Data Sourced

via OSV·02:15 PM

DescriptionSeverityAffected Software

Frequently Asked Questions

Which systems are most likely to be affected?

The issue affects RISC-V SMP boot configurations where NUMA is enabled and per-CPU data is placed in the vmalloc area. The provided reproduction uses a RISC-V QEMU virtual machine with two CPUs, CONFIG_NUMA=y, CONFIG_DEBUG_VIRTUAL=y, and percpu_alloc=page.

What conditions trigger the boot failure?

The failure occurs when the SBI hart-start path needs a physical address for boot data but that data was allocated in vmalloc-backed per-CPU storage. This can occur on very sparse configurations when the page per-CPU allocator is selected, including when booting with percpu_alloc=page.

What is the operational impact?

A newly started RISC-V hart can access an invalid address and immediately hang, preventing SMP boot from completing. The CVSS vector indicates local access and low privileges are required, with availability impact but no confidentiality or integrity impact.

How can administrators identify a potentially affected boot configuration?

Check whether the system is booting a RISC-V SMP kernel with NUMA enabled and the page per-CPU allocator in use, particularly if percpu_alloc=page is present in the kernel command line. Affected boots may hang as an additional hart is started.

UBUNTU-CVE-2025-38407: Medium severity ubuntu/linux-hwe-edge vulnerability

Affected Software

Remediation

Event History

Frequently Asked Questions

Which systems are most likely to be affected?

What conditions trigger the boot failure?

What is the operational impact?

How can administrators identify a potentially affected boot configuration?

Company

Resources

Contact

Frequently Asked Questions

Which systems are most likely to be affected?

What conditions trigger the boot failure?

What is the operational impact?

How can administrators identify a potentially affected boot configuration?