CVE-2024-56739: linux kernel — Fix

Description

In the Linux kernel, the following vulnerability has been resolved: rtc: check if __rtc_read_time was successful in rtc_timer_do_work() If the __rtc_read_time call fails,, the struct rtc_time tm; may contain uninitialized data, or an illegal date/time read from the RTC hardware. When calling rtc_tm_to_ktime later, the result may be a very large value (possibly KTIME_MAX). If there are periodic timers in rtc->timerqueue, they will continually expire, may causing kernel softlockup.

Is your site exposed to CVE-2024-56739?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

5.5

MEDIUM

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

Weakness Type (CWE)

CWE-908 CWE-908

Affected Products

Vendor	Product	Versions
linux	linux_kernel	2.6.38 — 4.19.325
linux	linux_kernel	4.20 — 5.4.287
linux	linux_kernel	5.5 — 5.10.231
linux	linux_kernel	5.11 — 5.15.174
linux	linux_kernel	5.16 — 6.1.120
linux	linux_kernel	6.2 — 6.6.64
linux	linux_kernel	6.7 — 6.11.11
linux	linux_kernel	6.12 — 6.12.2

References

Advisories & Patches

Other References

https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html

Frequently Asked Questions

What is CVE-2024-56739? +

In the Linux kernel, the following vulnerability has been resolved: rtc: check if __rtc_read_time was successful in rtc_timer_do_work() If the __rtc_read_time call fails,, the struct rtc_time tm; may contain uninitialized data, or an illegal date/time read from the RTC hardware. When calling rtc_tm_to_ktime later, the result may be a very large value (possibly KTIME_MAX). If there are periodic timers in rtc->timerqueue, they will continually expire, may causing kernel softlockup. It has a CVSS v3.1 base score of 5.5 (MEDIUM).

How severe is CVE-2024-56739? +

CVE-2024-56739 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.

What products are affected by CVE-2024-56739? +

CVE-2024-56739 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2024-56739? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-2329

In high traffic environments, a Silicon Labs OpenThread RCP (see impacted versions) fails to clear the SPI transmit buffer and …

CVE-2025-48513

Use of uninitialized resource within the AMD Platform Management Framework (PMF) could allow an attacker to read a uninitialized kernel …

CVE-2026-49425

The compat32 kevent() handler translates a 64-bit kevent struct into a stack- declared 32-bit struct. It did not first zero …

CVE-2026-49424

The Linux waitid() implementation translates a FreeBSD siginfo_t struct into a stack-declared Linux siginfo_t. It did not first zero the …

CVE-2026-58084

To retrieve the previous timer value, the kernel calls realtimer_gettime(), which obtains the current time for the timer's clock. For …

CVE-2026-49423

When building the iovec array for a received TLS 1.2 CBC record, ktls_ocf_tls_cbc_decrypt() incremented the iovec index for every mbuf …

CVE-2024-56739