CVE-2025-38183: net: lan743x: fix potential out-of-bounds write in lan743x_ptp_io_event_clock_get()

Severity: high (CVSS 7.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-04 · updated 2026-06-17
Weakness: CWE-787

Description

In the Linux kernel, the following vulnerability has been resolved: net: lan743x: fix potential out-of-bounds write in lan743x_ptp_io_event_clock_get() Before calling lan743x_ptp_io_event_clock_get(), the 'channel' value is checked against the maximum value of PCI11X1X_PTP_IO_MAX_CHANNELS(8). This seems correct and aligns with the PTP interrupt status register (PTP_INT_STS) specifications. However, lan743x_ptp_io_event_clock_get() writes to ptp->extts[] with only LAN743X_PTP_N_EXTTS(4) elements, using channel as an index: lan743x_ptp_io_event_clock_get(..., u8 channel,...) { ... /* Update Local timestamp */ extts = &ptp->extts[channel]; extts->ts.tv_sec = sec; ... } To avoid an out-of-bounds write and utilize all the supported GPIO inputs, set LAN743X_PTP_N_EXTTS to 8. Detected using the static analysis tool - Svace.

Affected products

Debian Linux: 11.0
Linux kernel: from 5.18 before 6.1.142; from 6.2 before 6.6.95; from 6.7 before 6.12.35; from 6.13 before 6.15.4; 6.16-rc1, 6.16-rc2 — fixed in 6.1.142, 6.12.35, 6.15.4, 6.6.95

How to fix

Upgrade to a fixed version: Linux kernel 6.1.142, 6.12.35, 6.15.4, 6.6.95. Check the vendor advisory for mitigations.

References

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