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

rtc: ac100: Fix clock provider use-after-free on probe failure

ac100_rtc_register_clks() registers the RTC-32k clock with
clk_hw_register_fixed_rate() and the clock provider with
of_clk_add_hw_provider(). Neither is device managed, and both are
released only from ac100_rtc_remove(). The driver core does not call
remove() when probe() fails: really_probe() reaches probe_failed below
the device_remove() call and goes straight to releasing the device's
managed resources.

ac100_rtc_probe() ends with

return devm_rtc_register_device(chip->rtc);

so if that fails after the clocks have been registered, the provider is
left on the global of_clk_providers list holding chip->clk_data, which
was allocated with devm_kzalloc() and is freed while probe() unwinds. A
later lookup on this device tree node then reads freed memory in
of_clk_hw_onecell_get(). Consumers that do exactly that exist in tree:
the wifi power sequence nodes on sun8i-a83t-bananapi-m3 and
sun8i-a83t-cubietruck-plus take <&ac100_rtc 1>, and the sun9i-a80 boards
route osc32k through <&ac100_rtc 0>. The window is narrow, as
devm_rtc_register_device() can only fail with -ENOMEM here, but the
provider is left dangling whenever it does.

The RTC-32k clock is leaked on the same path. Since clk_core_lookup()
searches a global list that is not scoped per device, __clk_register()
rejects the duplicate name with -EEXIST, so the leak also makes a later
probe of the same device fail.

The error path that returns -EINVAL when the ADDA 4M parent clock cannot
be found leaks the RTC-32k clock in the same way. No provider has been
registered at that point, so that one is a leak rather than a
use-after-free.

Register both with devm_clk_hw_register_fixed_rate() and
devm_of_clk_add_hw_provider() so that they are released whenever the
device goes away, on a failed probe as well as on unbind. Devres
releases in reverse order of acquisition, so the provider is removed
before chip->clk_data is freed, and the clkout children are now
unregistered before their parent rather than after it.
ac100_rtc_unregister_clks() and the remove callback then have nothing
left to do and are removed.

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Sun, 18 Oct 2026 20:45:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Sun, 18 Oct 2026 16:00:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: rtc: ac100: Fix clock provider use-after-free on probe failure ac100_rtc_register_clks() registers the RTC-32k clock with clk_hw_register_fixed_rate() and the clock provider with of_clk_add_hw_provider(). Neither is device managed, and both are released only from ac100_rtc_remove(). The driver core does not call remove() when probe() fails: really_probe() reaches probe_failed below the device_remove() call and goes straight to releasing the device's managed resources. ac100_rtc_probe() ends with return devm_rtc_register_device(chip->rtc); so if that fails after the clocks have been registered, the provider is left on the global of_clk_providers list holding chip->clk_data, which was allocated with devm_kzalloc() and is freed while probe() unwinds. A later lookup on this device tree node then reads freed memory in of_clk_hw_onecell_get(). Consumers that do exactly that exist in tree: the wifi power sequence nodes on sun8i-a83t-bananapi-m3 and sun8i-a83t-cubietruck-plus take <&ac100_rtc 1>, and the sun9i-a80 boards route osc32k through <&ac100_rtc 0>. The window is narrow, as devm_rtc_register_device() can only fail with -ENOMEM here, but the provider is left dangling whenever it does. The RTC-32k clock is leaked on the same path. Since clk_core_lookup() searches a global list that is not scoped per device, __clk_register() rejects the duplicate name with -EEXIST, so the leak also makes a later probe of the same device fail. The error path that returns -EINVAL when the ADDA 4M parent clock cannot be found leaks the RTC-32k clock in the same way. No provider has been registered at that point, so that one is a leak rather than a use-after-free. Register both with devm_clk_hw_register_fixed_rate() and devm_of_clk_add_hw_provider() so that they are released whenever the device goes away, on a failed probe as well as on unbind. Devres releases in reverse order of acquisition, so the provider is removed before chip->clk_data is freed, and the clkout children are now unregistered before their parent rather than after it. ac100_rtc_unregister_clks() and the remove callback then have nothing left to do and are removed.
Title rtc: ac100: Fix clock provider use-after-free on probe failure
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-18T15:49:19.709Z

Reserved: 2026-09-25T10:25:14.372Z

Link: CVE-2026-98826

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:36.823

Modified: 2026-10-18T16:17:36.823

Link: CVE-2026-98826

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-18T20:30:17Z

Weaknesses