CVE-2024-50195

/// Technical 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_s

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References