CVE-2025-38136

usb: renesas_usbhs: Reorder clock handling and power management in probe

published July 3, 2025

CVSS
—
EPSS
0%
Percentile
10.3
In the wild
Unconfirmed
What it is

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

usb: renesas_usbhs: Reorder clock handling and power management in probe

Reorder the initialization sequence in `usbhs_probe()` to enable runtime

PM before accessing registers, preventing potential crashes due to

uninitialized clocks.

Currently, in the probe path, registers are accessed before enabling the

clocks, leading to a synchronous external abort on the RZ/V2H SoC.

The problematic call flow is as follows:

usbhs_probe()

usbhs_sys_clock_ctrl()

usbhs_bset()

usbhs_write()

iowrite16() <-- Register access before enabling clocks

Since `iowrite16()` is performed without ensuring the required clocks are

enabled, this can lead to access errors. To fix this, enable PM runtime

early in the probe function and ensure clocks are acquired before register

access, preventing crashes like the following on RZ/V2H:

[13.272640] Internal error: synchronous external abort: 0000000096000010 [#1] PREEMPT SMP

[13.280814] Modules linked in: cec renesas_usbhs(+) drm_kms_helper fuse drm backlight ipv6

[13.289088] CPU: 1 UID: 0 PID: 195 Comm: (udev-worker) Not tainted 6.14.0-rc7+ #98

[13.296640] Hardware name: Renesas RZ/V2H EVK Board based on r9a09g057h44 (DT)

[13.303834] pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)

[13.310770] pc : usbhs_bset+0x14/0x4c [renesas_usbhs]

[13.315831] lr : usbhs_probe+0x2e4/0x5ac [renesas_usbhs]

[13.321138] sp : ffff8000827e3850

[13.324438] x29: ffff8000827e3860 x28: 0000000000000000 x27: ffff8000827e3ca0

[13.331554] x26: ffff8000827e3ba0 x25: ffff800081729668 x24: 0000000000000025

[13.338670] x23: ffff0000c0f08000 x22: 0000000000000000 x21: ffff0000c0f08010

[13.345783] x20: 0000000000000000 x19: ffff0000c3b52080 x18: 00000000ffffffff

[13.352895] x17: 0000000000000000 x16: 0000000000000000 x15: ffff8000827e36ce

[13.360009] x14: 00000000000003d7 x13: 00000000000003d7 x12: 0000000000000000

[13.367122] x11: 0000000000000000 x10: 0000000000000aa0 x9 : ffff8000827e3750

[13.374235] x8 : ffff0000c1850b00 x7 : 0000000003826060 x6 : 000000000000001c

[13.381347] x5 : 000000030d5fcc00 x4 : ffff8000825c0000 x3 : 0000000000000000

[13.388459] x2 : 0000000000000400 x1 : 0000000000000000 x0 : ffff0000c3b52080

[13.395574] Call trace:

[13.398013] usbhs_bset+0x14/0x4c [renesas_usbhs] (P)

[13.403076] platform_probe+0x68/0xdc

[13.406738] really_probe+0xbc/0x2c0

[13.410306] __driver_probe_device+0x78/0x120

[13.414653] driver_probe_device+0x3c/0x154

[13.418825] __driver_attach+0x90/0x1a0

[13.422647] bus_for_each_dev+0x7c/0xe0

[13.426470] driver_attach+0x24/0x30

[13.430032] bus_add_driver+0xe4/0x208

[13.433766] driver_register+0x68/0x130

[13.437587] __platform_driver_register+0x24/0x30

[13.442273] renesas_usbhs_driver_init+0x20/0x1000 [renesas_usbhs]

[13.448450] do_one_initcall+0x60/0x1d4

[13.452276] do_init_module+0x54/0x1f8

[13.456014] load_module+0x1754/0x1c98

[13.459750] init_module_from_file+0x88/0xcc

[13.464004] __arm64_sys_finit_module+0x1c4/0x328

[13.468689] invoke_syscall+0x48/0x104

[13.472426] el0_svc_common.constprop.0+0xc0/0xe0

[13.477113] do_el0_svc+0x1c/0x28

[13.480415] el0_svc+0x30/0xcc

[13.483460] el0t_64_sync_handler+0x10c/0x138

[13.487800] el0t_64_sync+0x198/0x19c

[13.491453] Code: 2a0103e1 12003c42 12003c63 8b010084 (79400084)

[13.497522] ---[ end trace 0000000000000000 ]---

The record
Technical detail
CVSS
Not scored
CVSS v4.0
Not supplied
EPSS
0.00208 · 10.3th percentile
Published
2025-07-03T08:35Z
EPSS history
Timeline
  • 03 JUL 08:35Z
    usb: renesas_usbhs: Reorder clock handling and power management in probe
    cvelistv5