NULL pointer dereference in Linux

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().

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.5 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.002 (8.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 9th percentile — 8.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2024-56621: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

  • Linux — versions 06701a545e9a3c4e007cff6872a074bf97c40619, 6bf999e0eb41850d5c857102535d5c53b2ede224, 6.8
  • Linux Kernel — versions 6.13

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2024-56621?
CVE-2024-56621 is a medium-severity vulnerability in Linux, classified under NULL Pointer Dereference. CVSS score: 5.5/10. Published 2024-12-27.
How severe is CVE-2024-56621?
Medium severity. CVSS v3 base score is 5.5 out of 10.
Is CVE-2024-56621 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.