CVE-2025-38136

CVE-2025-38136 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-908.

Key facts

Description

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 ]---

Frequently asked questions

What is CVE-2025-38136?
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 ]---
How severe is CVE-2025-38136?
CVE-2025-38136 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2025-38136 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (7th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-38136?
CVE-2025-38136 primarily affects Linux Linux Kernel. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2025-38136?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-38136 have an EU (EUVD) identifier?
Yes. CVE-2025-38136 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-19807.
When was CVE-2025-38136 published?
CVE-2025-38136 was published on 2025-07-03 and last updated on 2026-06-17.

References

Affected products (2)

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