CVE-2025-38284
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: wifi: rtw89: pci: configure manual DAC mode via PCI config API only To support 36-bit DMA, configure chip proprietary bit via PCI config API or chip DBI interface. However, the PCI device mmap isn't set yet and the DBI is also inaccessible via mmap, so only if the bit can be accessible via PCI config API, chip can support 36-bit DMA. Otherwise, fallback to 32-bit DMA. With NULL mmap address, kernel throws trace: BUG: unable to handle page fault for address: 0000000000001090 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: Oops: 0002 [#1] PREEMPT SMP PTI CPU: 1 UID: 0 PID: 71 Comm: irq/26-pciehp Tainted: G OE 6.14.2-061402-generic #202504101348 Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE RIP: 0010:rtw89_pci_ops_write16+0x12/0x30 [rtw89_pci] RSP: 0018:ffffb0ffc0acf9d8 EFLAGS: 00010206 RAX: ffffffffc158f9c0 RBX: ffff94865e702020 RCX: 0000000000000000 RDX: 0000000000000718 RSI: 0000000000001090 RDI: ffff94865e702020 RBP: ffffb0ffc0acf9d8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000015 R13: 0000000000000719 R14: ffffb0ffc0acfa1f R15: ffffffffc1813060 FS: 0000000000000000(0000) GS:ffff9486f3480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000001090 CR3: 0000000090440001 CR4: 00000000000626f0 Call Trace: <TASK> rtw89_pci_read_config_byte+0x6d/0x120 [rtw89_pci] rtw89_pci_cfg_dac+0x5b/0xb0 [rtw89_pci] rtw89_pci_probe+0xa96/0xbd0 [rtw89_pci] ? __pfx___device_attach_driver+0x10/0x10 ? __pfx___device_attach_driver+0x10/0x10 local_pci_probe+0x47/0xa0 pci_call_probe+0x5d/0x190 pci_device_probe+0xa7/0x160 really_probe+0xf9/0x370 ? pm_runtime_barrier+0x55/0xa0 __driver_probe_device+0x8c/0x140 driver_probe_device+0x24/0xd0 __device_attach_driver+0xcd/0x170 bus_for_each_drv+0x99/0x100 __device_attach+0xb4/0x1d0 device_attach+0x10/0x20 pci_bus_add_device+0x59/0x90 pci_bus_add_devices+0x31/0x80 pciehp_configure_device+0xaa/0x170 pciehp_enable_slot+0xd6/0x240 pciehp_handle_presence_or_link_change+0xf1/0x180 pciehp_ist+0x162/0x1c0 irq_thread_fn+0x24/0x70 irq_thread+0xef/0x1c0 ? __pfx_irq_thread_fn+0x10/0x10 ? __pfx_irq_thread_dtor+0x10/0x10 ? __pfx_irq_thread+0x10/0x10 kthread+0xfc/0x230 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x47/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 </TASK>
Statement
A kernel crash was fixed in the rtw89_pci driver where an attempt to access a NULL mmap address caused a page fault. The bug occurred during the early PCI initialization phase, where driver code incorrectly assumed that memory-mapped I/O had already been established. The fix ensures DAC configuration is performed exclusively via the PCI config API before mapping is valid. This issue can lead to a kernel panic, especially when the driver is autoloaded for specific Realtek wireless chipsets. This vulnerability leads to a kernel crash during driver initialization or hotplug scenarios, affecting only the system's availability. There is no evidence of data disclosure or modification, hence the impact on confidentiality and integrity is considered None.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.1 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | None | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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