CVE-2024-50195 Information

Nov 09, 2024 cve

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..999999999] 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.

Reference

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