CVE-2024-56621: In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Cancel RTC work during ufshcd_remove() Currently, RTC work is o...

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Cancel RTC work during ufshcd_remove() Currently, RTC work is only cancelled during __ufshcd_wl_suspend(). When ufshcd is removed in ufshcd_remove(), RTC work is not cancelled. Due to this, any further trigger of the RTC work after ufshcd_remove() would result in a NULL pointer dereference as below: Unable to handle kernel NULL pointer dereference at virtual address 00000000000002a4 Workqueue: events ufshcd_rtc_work Call trace: _raw_spin_lock_irqsave+0x34/0x8c pm_runtime_get_if_active+0x24/0xb4 ufshcd_rtc_work+0x124/0x19c process_scheduled_works+0x18c/0x2d8 worker_thread+0x144/0x280 kthread+0x11c/0x128 ret_from_fork+0x10/0x20 Since RTC work accesses the ufshcd internal structures, it should be cancelled when ufshcd is removed. So do that in ufshcd_remove(), as per the order in ufshcd_init().

Metrics

CVSS 3.1

5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.19%

9.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-476

Affected Software

Vendor	Product	Versions	Update
Linux	Linux Kernel	>= 6.8, < 6.12.5	—
Linux	Linux Kernel	6.13	Rc1

References

Timeline

Published: Dec 27, 2024
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2024-56621?

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Cancel RTC work during ufshcd_remove() Currently, RTC work is only cancelled during __ufshcd_wl_suspend(). When ufshcd is removed in ufshcd_remove(), RTC work is not cancelled. Due to this, any further trigger of the RTC work after ufshcd_remove() would result in a NULL pointer dereference as below: Unable to handle kernel NULL pointer dereference at virtual address 00000000000002a4 Workqueue: events ufshcd_rtc_work Call trace: _raw_spin_lock_irqsave+0x34/0x8c pm_runtime_get_if_active+0x24/0xb4 ufshcd_rtc_work+0x124/0x19c process_scheduled_works+0x18c/0x2d8 worker_thread+0x144/0x280 kthread+0x11c/0x128 ret_from_fork+0x10/0x20 Since RTC work accesses the ufshcd internal structures, it should be cancelled when ufshcd is removed. So do that in ufshcd_remove(), as per the order in ufshcd_init().

How severe is CVE-2024-56621?

CVE-2024-56621 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.19% probability of exploitation in the next 30 days.

How do I fix CVE-2024-56621?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.