rtc: check if __rtc_read_time was successful in rtc_timer_do_work()
Priority LOW 24CWE-908Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 fixed, 2 without a fix
Attack profile from CVSS 3.1 · CISA ADP. Fix status from CNA and Red Hat. Impact type from CWE-908 and the CVSS impact.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00232 14th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.19.325, 5.4.287, 5.10.231 +6Red Hat: 1 advisoryRed Hat: 5 fixed, 2 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 2.6.38 and later | 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13 | Patch available | CNA |
- Linux VendorLinux Affected 2.6.38 and later Fixed in 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 2.6.38 to before 4.19.325; 4.20 to before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.64; 6.7 to before 6.11.11; 6.12 to before 6.12.2 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 2.6.38 to before 4.19.325; 4.20 to before 5.4.287; 5.5 to before 5.10.231; 5.11 to before 5.15.174; 5.16 to before 6.1.120; 6.2 to before 6.6.64; 6.7 to before 6.11.11; 6.12 to before 6.12.2 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.19.325, 5.4.287, 5.10.231, 5.15.174, 6.1.120, 6.6.64, 6.11.11, 6.12.2, 6.13
Red Hat 1 advisory
- RHSA-2025:20518 Released 2025-11-11 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-611.5.1.el9_7, kernel-64k-debug-devel-matched-5.14.0-611.5.1.el9_7, kernel-64k-devel-5.14.0-611.5.1.el9_7 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-611.5.1.el9_7, kernel-64k-5.14.0-611.5.1.el9_7, kernel-64k-core-5.14.0-611.5.1.el9_7 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-611.5.1.el9_7, libperf-5.14.0-611.5.1.el9_7
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-611.5.1.el9_7, kernel-rt-64k-5.14.0-611.5.1.el9_7, kernel-rt-64k-core-5.14.0-611.5.1.el9_7 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-611.5.1.el9_7, kernel-rt-core-5.14.0-611.5.1.el9_7, kernel-rt-debug-5.14.0-611.5.1.el9_7 +9
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2025:20518 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2025:20518 |
Not affected: 2 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
Timeline
- 2026-10-02 Threatist record created from CVE-2024-56739
- 2026-10-03 Alias added: GHSA-42wq-32p9-mf48
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 9
- https://git.kernel.org/stable/c/39ad0a1ae17b54509cd9e93dcd8cec16e7c12d3f
- https://git.kernel.org/stable/c/44b3257ff705d63d5f00ef8ed314a0eeb7ec37f2
- https://git.kernel.org/stable/c/0d68e8514d9040108ff7d1b37ca71096674b6efe
- https://git.kernel.org/stable/c/246f621d363988e7040f4546d20203dc713fa3e1
- https://git.kernel.org/stable/c/fde56535505dde3336df438e949ef4742b6d6d6e
- https://git.kernel.org/stable/c/dd4b1cbcc916fad5d10c2662b62def9f05e453d4
- https://git.kernel.org/stable/c/a1f0b4af90cc18b10261ecde56c6a56b22c75bd1
- https://git.kernel.org/stable/c/e77bce0a8c3989b4173c36f4195122bca8f4a3e1
- https://git.kernel.org/stable/c/e8ba8a2bc4f60a1065f23d6a0e7cbea945a0f40d
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-56739 · CVE Program
- CVE-2024-56739 · NVD
- FIRST EPSS
- GHSA-42wq-32p9-mf48 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-56739 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences