Linux Kernel up to 6.12.45/6.16.5 of_numa free_area_init null pointer dereference

Summaryinfo

A vulnerability, which was classified as critical, has been found in Linux Kernel up to 6.12.45/6.16.5. This impacts the function free_area_init of the component of_numa. This manipulation causes null pointer dereference. This vulnerability is tracked as CVE-2025-39903. No exploit exists. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.12.45/6.16.5. Affected by this vulnerability is the function free_area_init of the component of_numa. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: of_numa: fix uninitialized memory nodes causing kernel panic When there are memory-only nodes (nodes without CPUs), these nodes are not properly initialized, causing kernel panic during boot. of_numa_init of_numa_parse_cpu_nodes node_set(nid, numa_nodes_parsed); of_numa_parse_memory_nodes In of_numa_parse_cpu_nodes, numa_nodes_parsed gets updated only for nodes containing CPUs. Memory-only nodes should have been updated in of_numa_parse_memory_nodes, but they weren't. Subsequently, when free_area_init() attempts to access NODE_DATA() for these uninitialized memory nodes, the kernel panics due to NULL pointer dereference. This can be reproduced on ARM64 QEMU with 1 CPU and 2 memory nodes: qemu-system-aarch64 \ -cpu host -nographic \ -m 4G -smp 1 \ -machine virt,accel=kvm,gic-version=3,iommu=smmuv3 \ -object memory-backend-ram,size=2G,id=mem0 \ -object memory-backend-ram,size=2G,id=mem1 \ -numa node,nodeid=0,memdev=mem0 \ -numa node,nodeid=1,memdev=mem1 \ -kernel $IMAGE \ -hda $DISK \ -append "console=ttyAMA0 root=/dev/vda rw earlycon" [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x481fd010] [ 0.000000] Linux version 6.17.0-rc1-00001-gabb4b3daf18c-dirty (yintirui@local) (gcc (GCC) 12.3.1, GNU ld (GNU Binutils) 2.41) #52 SMP PREEMPT Mon Aug 18 09:49:40 CST 2025 [ 0.000000] KASLR enabled [ 0.000000] random: crng init done [ 0.000000] Machine model: linux,dummy-virt [ 0.000000] efi: UEFI not found. [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '') [ 0.000000] printk: legacy bootconsole [pl11] enabled [ 0.000000] OF: reserved mem: Reserved memory: No reserved-memory node in the DT [ 0.000000] NODE_DATA(0) allocated [mem 0xbfffd9c0-0xbfffffff] [ 0.000000] node 1 must be removed before remove section 23 [ 0.000000] Zone ranges: [ 0.000000] DMA [mem 0x0000000040000000-0x00000000ffffffff] [ 0.000000] DMA32 empty [ 0.000000] Normal [mem 0x0000000100000000-0x000000013fffffff] [ 0.000000] Movable zone start for each node [ 0.000000] Early memory node ranges [ 0.000000] node 0: [mem 0x0000000040000000-0x00000000bfffffff] [ 0.000000] node 1: [mem 0x00000000c0000000-0x000000013fffffff] [ 0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x00000000bfffffff] [ 0.000000] Unable to handle kernel NULL pointer dereference at virtual address 00000000000000a0 [ 0.000000] Mem abort info: [ 0.000000] ESR = 0x0000000096000004 [ 0.000000] EC = 0x25: DABT (current EL), IL = 32 bits [ 0.000000] SET = 0, FnV = 0 [ 0.000000] EA = 0, S1PTW = 0 [ 0.000000] FSC = 0x04: level 0 translation fault [ 0.000000] Data abort info: [ 0.000000] ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 [ 0.000000] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 0.000000] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 0.000000] [00000000000000a0] user address but active_mm is swapper [ 0.000000] Internal error: Oops: 0000000096000004 [#1] SMP [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.17.0-rc1-00001-g760c6dabf762-dirty #54 PREEMPT [ 0.000000] Hardware name: linux,dummy-virt (DT) [ 0.000000] pstate: 800000c5 (Nzcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 0.000000] pc : free_area_init+0x50c/0xf9c [ 0.000000] lr : free_area_init+0x5c0/0xf9c [ 0.000000] sp : ffffa02ca0f33c00 [ 0.000000] x29: ffffa02ca0f33cb0 x28: 0000000000000000 x27: 0000000000000000 [ 0.000000] x26: 4ec4ec4ec4ec4ec5 x25: 00000000000c0000 x24: 00000000000c0000 [ 0.000000] x23: 0000000000040000 x22: 0000000000000000 x21: ffffa02ca0f3b368 [ 0.000000] x20: ffffa02ca14c7b98 x19: 0000000000000000 x18: 0000000000000002 [ 0.000000] x17: 000000000000cacc x16: 0000000000000001 x15: 0000000000000001 [ 0.000000] x14: 0000000080000000 x13: 0000000000000018 x12: 0000000000000002 [ 0.0 ---truncated---

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2025-39903 since 04/16/2025. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 269686 (Linux Distros Unpatched Vulnerability : CVE-2025-39903), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.46 or 6.16.6 eliminates this vulnerability. Applying the patch c2daa6eb4740720b5bd0e06267d7c93a3eed844e/f3286ad8eeae15fd4bd5c12f9adfe888b26baf62/ee4d098cbc9160f573b5c1b5a51d6158efdb2896 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (269686) and CERT Bund (WID-SEC-2025-2170). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.16.0
• 6.16.1
• 6.16.2
• 6.16.3
• 6.16.4
• 6.16.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Threat Intelligenceinfo

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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