CVE-2025-38407

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

riscv: cpu_ops_sbi: Use static array for boot_data

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 percpu_alloc=page.

In that case, percpu data gets put in the vmalloc area. However, sbi_hsm_hart_start() needs the physical address of a sbi_hart_boot_data, and simply assumes that __pa() would work. This causes the just started hart to immediately access an invalid address and hang.

Fortunately, struct sbi_hart_boot_data is not too large, so we can simply allocate an array for boot_data statically, putting it in the kernel image.

This fixes NUMA=y SMP boot on Sophgo SG2042.

To reproduce on QEMU: Set CONFIG_NUMA=y and CONFIG_DEBUG_VIRTUAL=y, then run with:

qemu-system-riscv64 -M virt -smp 2 -nographic -kernel arch/riscv/boot/Image -append percpu_alloc=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] virt_to_phys used for non-linear address: (ptrval) (0xff2000000001d080) [ 0.088001] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:14 __virt_to_phys+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 : __virt_to_phys+0xae/0xe8 [ 0.089001] ra : __virt_to_phys+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] [] __virt_to_phys+0xae/0xe8 [ 0.090228] [] sbi_cpu_start+0x6e/0xe8 [ 0.090247] [] __cpu_up+0x1e/0x8c [ 0.090260] [] bringup_cpu+0x42/0x258 [ 0.090277] [] cpuhp_invoke_callback+0xe0/0x40c [ 0.090292] [] __cpuhp_invoke_callback_range+0x68/0xfc [ 0.090320] [] _cpu_up+0x11a/0x244 [ 0.090334] [] cpu_up+0x52/0x90 [ 0.090384] [] bringup_nonboot_cpus+0x78/0x118 [ 0.090411] [] smp_init+0x34/0xb8 [ 0.090425] [] kernel_init_freeable+0x148/0x2e4 [ 0.090442] [] kernel_init+0x1e/0x14c [ 0.090455] [] ret_from_fork_kernel+0xe/0xf0 [ 0.090471] [] ret_from_fork_kernel_asm+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

References

• https://git.kernel.org/stable/c/02c725cd55eb5052b88eeaa3f60a391ef4dcaec5
• https://git.kernel.org/stable/c/2b29be967ae456fc09c320d91d52278cf721be1e
• https://git.kernel.org/stable/c/f5fe094f35a37adea40b2fd52c99bb1333be9b07