CVE-2024-58069
📋 TL;DR
This vulnerability in the Linux kernel's PCF85063 RTC driver allows out-of-bounds memory writes when reading NVMEM data with small buffers. It affects systems using this specific RTC hardware driver, potentially leading to kernel memory corruption. The risk primarily impacts embedded systems and devices with this particular RTC chip.
💻 Affected Systems
- Linux kernel with PCF85063 RTC driver
📦 What is this software?
Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →Linux Kernel by Linux
The Linux Kernel is the core component of the Linux operating system, serving as the critical interface between computer hardware and software processes. As the heart of millions of servers, cloud infrastructure, embedded systems, Android devices, and IoT deployments worldwide, the Linux Kernel mana...
Learn more about Linux Kernel →⚠️ Risk & Real-World Impact
Worst Case
Kernel memory corruption leading to system crash, privilege escalation, or arbitrary code execution in kernel context.
Likely Case
System instability, kernel panics, or denial of service when accessing RTC NVMEM with malformed requests.
If Mitigated
No impact if the vulnerable driver is not loaded or if NVMEM access is properly restricted.
🎯 Exploit Status
Requires local access and ability to trigger specific NVMEM read operations with small buffers. No known public exploits.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Kernel versions containing the fix commits: 21cd59fcb9952eb7505da2bdfc1eb9c619df3ff4, 3ab8c5ed4f84fa20cd16794fe8dc31f633fbc70c, 517aedb365f2c94e2d7e0b908ac7127df76203a1, 6f2a8ca9a0a38589f52a7f0fb9425b9ba987ae7c, 9adefa7b9559d0f21034a5d5ec1b55840c9348b9
Vendor Advisory: https://git.kernel.org/stable/c/21cd59fcb9952eb7505da2bdfc1eb9c619df3ff4
Restart Required: No
Instructions:
1. Update Linux kernel to version containing the fix commits. 2. For embedded systems: Rebuild kernel with patched driver. 3. For distributions: Apply security updates from your vendor.
🔧 Temporary Workarounds
Disable PCF85063 driver
allPrevent loading of the vulnerable driver if RTC functionality is not required
echo 'blacklist rtc-pcf85063' >> /etc/modprobe.d/blacklist.conf
rmmod rtc-pcf85063
Restrict NVMEM access
allLimit access to RTC NVMEM interface to trusted processes only
chmod 600 /sys/class/rtc/rtc*/nvmem
setfacl -m u:root:rw /sys/class/rtc/rtc*/nvmem
🧯 If You Can't Patch
- Isolate systems with vulnerable driver from untrusted users
- Implement strict access controls on /sys/class/rtc interfaces
🔍 How to Verify
Check if Vulnerable:
Check if PCF85063 driver is loaded: lsmod | grep pcf85063 && check kernel version against patched commitsCheck Version:
uname -r && grep -r 'pcf85063' /sys/class/rtc/Verify Fix Applied:
Verify kernel version includes fix commits and driver loads without errors in dmesg📡 Detection & Monitoring
Log Indicators:
- Kernel oops messages mentioning pcf85063
- Segmentation faults in processes accessing RTC
- Unexpected system reboots
Network Indicators:
- None - local vulnerability only
SIEM Query:
source="kernel" AND ("pcf85063" OR "rtc" AND "oops" OR "segfault")🔗 References
- https://git.kernel.org/stable/c/21cd59fcb9952eb7505da2bdfc1eb9c619df3ff4
- https://git.kernel.org/stable/c/3ab8c5ed4f84fa20cd16794fe8dc31f633fbc70c
- https://git.kernel.org/stable/c/517aedb365f2c94e2d7e0b908ac7127df76203a1
- https://git.kernel.org/stable/c/6f2a8ca9a0a38589f52a7f0fb9425b9ba987ae7c
- https://git.kernel.org/stable/c/9adefa7b9559d0f21034a5d5ec1b55840c9348b9
- https://git.kernel.org/stable/c/c72b7a474d3f445bf0c5bcf8ffed332c78eb28a1
- https://git.kernel.org/stable/c/e5536677da803ed54a29a446515c28dce7d3d574
- https://git.kernel.org/stable/c/e5e06455760f2995b16a176033909347929d1128
- https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
