VulnerabilityPublished 12 Nov 2025Updated 31 Jul 2026

CVE-2025-40189: Linux kernel · net: usb: lan78xx: Fix lost EEPROM read timeout error(-ETIMEDOUT) in

Affects Linux kernelSource GCVE Database

Not known to be exploited · fixed in 6.17.0-1007.7~24.04.1 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 14:05 UTC

Severity

Medium

Rated by Threat Radar · No CVSS score from NVD or the CNA

EPSS: 0.1% chance of exploitation in 30 days – higher than 9% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 6.17.0-1007.7~24.04.1, 6.17.0-1008.8~24.04.1, 6.17.0-1008.8 +6

Exploitation evidence

Disclosed: evidence found.
CVE published 12 Nov 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade to a fixed release listed under Affected software.

Patches and advisories

Affected software

Product	Affected	Fixed in
Ubuntu 25.10linux`pkg:deb/ubuntu/linux?arch=source&distro=questing`Other threats	Affected <6.17.0-14.14	Fixed in 6.17.0-14.14
Ubuntu 25.10linux-aws`pkg:deb/ubuntu/linux-aws?arch=source&distro=questing`Other threats	Affected <6.17.0-1007.7	Fixed in 6.17.0-1007.7
Ubuntu 25.10linux-azure`pkg:deb/ubuntu/linux-azure?arch=source&distro=questing`Other threats	Affected <6.17.0-1008.8	Fixed in 6.17.0-1008.8
Ubuntu 25.10linux-azure-fde`pkg:deb/ubuntu/linux-azure-fde?arch=source&distro=questing`Other threats	Affected 6.17.0-1003.3 – 6.17.0-1017.17 10 affected builds	Fixed in–
Ubuntu 25.10linux-gcp`pkg:deb/ubuntu/linux-gcp?arch=source&distro=questing`Other threats	Affected <6.17.0-1007.7	Fixed in 6.17.0-1007.7
Ubuntu 25.10linux-oracle`pkg:deb/ubuntu/linux-oracle?arch=source&distro=questing`Other threats	Affected <6.17.0-1007.7	Fixed in 6.17.0-1007.7

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

Description

In the Linux kernel, the following vulnerability has been resolved: net: usb: lan78xx: Fix lost EEPROM read timeout error(-ETIMEDOUT) in lan78xx_read_raw_eeprom Syzbot reported read of uninitialized variable BUG with following call stack. lan78xx 8-1:1.0 (unnamed net_device) (uninitialized): EEPROM read operation timeout ===================================================== BUG: KMSAN: uninit-value in lan78xx_read_eeprom drivers/net/usb/lan78xx.c:1095 [inline] BUG: KMSAN: uninit-value in lan78xx_init_mac_address drivers/net/usb/lan78xx.c:1937 [inline] BUG: KMSAN: uninit-value in lan78xx_reset+0x999/0x2cd0 drivers/net/usb/lan78xx.c:3241 lan78xx_read_eeprom drivers/net/usb/lan78xx.c:1095 [inline] lan78xx_init_mac_address drivers/net/usb/lan78xx.c:1937 [inline] lan78xx_reset+0x999/0x2cd0 drivers/net/usb/lan78xx.c:3241 lan78xx_bind+0x711/0x1690 drivers/net/usb/lan78xx.c:3766 lan78xx_probe+0x225c/0x3310 drivers/net/usb/lan78xx.c:4707 Local variable sig.i.i created at: lan78xx_read_eeprom drivers/net/usb/lan78xx.c:1092 [inline] lan78xx_init_mac_address drivers/net/usb/lan78xx.c:1937 [inline] lan78xx_reset+0x77e/0x2cd0 drivers/net/usb/lan78xx.c:3241 lan78xx_bind+0x711/0x1690 drivers/net/usb/lan78xx.c:3766 The function lan78xx_read_raw_eeprom failed to properly propagate EEPROM read timeout errors (-ETIMEDOUT). In the fallthrough path, it first attempted to restore the pin configuration for LED outputs and then returned only the status of that restore operation, discarding the original timeout error. As a result, callers could mistakenly treat the data buffer as valid even though the EEPROM read had actually timed out with no data or partial data. To fix this, handle errors in restoring the LED pin configuration separately. If the restore succeeds, return any prior EEPROM timeout error correctly to the caller.

References

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