CVE-2024-50195 posix-clock: Fix missing timespec64 check in pc_clock_settime()
Missing input validation in Linux kernel PTP clock setting allows invalid time values to reach drivers, potentially causing system instability or crashes.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-50195?
CVE-2024-50195 is a high-severity vulnerability in Linux kernel, published on 8 Nov 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
posix-clock: Fix missing timespec64 check in pc_clock_settime()
As Andrew pointed out, it will make sense that the PTP core checked timespec64 struct's tv_sec and tv_nsec range before calling ptp->info->settime64().
As the man manual of clock_settime() said, if tp.tv_sec is negative or tp.tv_nsec is outside the range [0..999,999,999], it should return EINVAL, which include dynamic clocks which handles PTP clock, and the condition is consistent with timespec64_valid(). As Thomas suggested, timespec64_valid() only check the timespec is valid, but not ensure that the time is in a valid range, so check it ahead using timespec64_valid_strict() in pc_clock_settime() and return -EINVAL if not valid.
There are some drivers that use tp->tv_sec and tp->tv_nsec directly to write registers without validity checks and assume that the higher layer has checked it, which is dangerous and will benefit from this, such as hclge_ptp_settime(), igb_ptp_settime_i210(), _rcar_gen4_ptp_settime(), and some drivers can remove the checks of itself.
Weakness: CWE-754
Which versions are affected by CVE-2024-50195?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-50195?
Apply the vendor's patch.
Is CVE-2024-50195 being exploited?
There is no known exploitation of CVE-2024-50195 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-53420, AZL-53739, BELL-CVE-2024-50195, DEBIAN-CVE-2024-50195, GHSA-v787-c3f2-p88r, UBUNTU-CVE-2024-50195.