CVE-2025-38407
RISC-V Linux: CPU Ops SBI Use-After-Free
Description
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] [<ffffffff80021eaa>] __virt_to_phys+0xae/0xe8 [ 0.090228] [<ffffffff8001d796>] sbi_cpu_start+0x6e/0xe8 [ 0.090247] [<ffffffff8001a5da>] __cpu_up+0x1e/0x8c [ 0.090260] [<ffffffff8002a32e>] bringup_cpu+0x42/0x258 [ 0.090277] [<ffffffff8002914c>] cpuhp_invoke_callback+0xe0/0x40c [ 0.090292] [<ffffffff800294e0>] __cpuhp_invoke_callback_range+0x68/0xfc [ 0.090320] [<ffffffff8002a96a>] _cpu_up+0x11a/0x244 [ 0.090334] [<ffffffff8002aae6>] cpu_up+0x52/0x90 [ 0.090384] [<ffffffff80c09350>] bringup_nonboot_cpus+0x78/0x118 [ 0.090411] [<ffffffff80c11060>] smp_init+0x34/0xb8 [ 0.090425] [<ffffffff80c01220>] kernel_init_freeable+0x148/0x2e4 [ 0.090442] [<ffffffff80b83802>] kernel_init+0x1e/0x14c [ 0.090455] [<ffffffff800124ca>] ret_from_fork_kernel+0xe/0xf0 [ 0.090471] [<ffffffff80b8d9c2>] 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
INFO
Published Date :
July 25, 2025, 2:15 p.m.
Last Modified :
July 25, 2025, 3:29 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- There is no known solution at this time.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-38407.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-38407 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-38407
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-38407 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-38407 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2025
Action Type Old Value New Value Added Description 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] [<ffffffff80021eaa>] __virt_to_phys+0xae/0xe8 [ 0.090228] [<ffffffff8001d796>] sbi_cpu_start+0x6e/0xe8 [ 0.090247] [<ffffffff8001a5da>] __cpu_up+0x1e/0x8c [ 0.090260] [<ffffffff8002a32e>] bringup_cpu+0x42/0x258 [ 0.090277] [<ffffffff8002914c>] cpuhp_invoke_callback+0xe0/0x40c [ 0.090292] [<ffffffff800294e0>] __cpuhp_invoke_callback_range+0x68/0xfc [ 0.090320] [<ffffffff8002a96a>] _cpu_up+0x11a/0x244 [ 0.090334] [<ffffffff8002aae6>] cpu_up+0x52/0x90 [ 0.090384] [<ffffffff80c09350>] bringup_nonboot_cpus+0x78/0x118 [ 0.090411] [<ffffffff80c11060>] smp_init+0x34/0xb8 [ 0.090425] [<ffffffff80c01220>] kernel_init_freeable+0x148/0x2e4 [ 0.090442] [<ffffffff80b83802>] kernel_init+0x1e/0x14c [ 0.090455] [<ffffffff800124ca>] ret_from_fork_kernel+0xe/0xf0 [ 0.090471] [<ffffffff80b8d9c2>] 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 Added Reference https://git.kernel.org/stable/c/02c725cd55eb5052b88eeaa3f60a391ef4dcaec5 Added Reference https://git.kernel.org/stable/c/2b29be967ae456fc09c320d91d52278cf721be1e Added Reference https://git.kernel.org/stable/c/f5fe094f35a37adea40b2fd52c99bb1333be9b07