CVE-2025-38284

What the bug is

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>

Where it lives

The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.

drivers/net/wireless/realtek/rtw89/pci.c

What this is

REALTEK WIRELESS DRIVER (rtw89)MAINTAINERS section matched on drivers/net/wireless/realtek/rtw89/ · linux-wireless@vger.kernel.org · Maintained

Kernel module

rtw89_pci

Check it on the machine

grep -wE 'CONFIG_RTW89|CONFIG_RTW89_PCI|CONFIG_WLAN|CONFIG_WLAN_VENDOR_REALTEK' /boot/config-$(uname -r)

Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.

lsmod | grep -w rtw89_pci

Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.

Show whether Debian builds this, per release

Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.

• bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
• trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, s390x/s390x
• forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x

M

a module where it is built at all; some flavours do not build it

Build switches

CONFIG_RTW89, CONFIG_RTW89_PCI, CONFIG_WLAN, CONFIG_WLAN_VENDOR_REALTEK

Reads as

all on means the file is compiled; any one off means it is not.

From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages

Signals

Published

2025-07-10 (15 months ago)source

CVSS

no vector published, unrated

Attack vector

not published

EPSS

0.16%, higher than 4.6% of all CVEssource

CISA KEV

not listedthe KEV catalogue

Debian urgency

unimportantsource

Subsystem

drivers/net

Upstream fixes

The versions the CNA records as introducing and fixing this, and the commit for each. source

Introduced	Fixed in	Commit
6.11	6.15.3	e1e0f0460414
6.11	6.16	a70cf04b08f4