CVE-2026-72391

Summary

In the Linux kernel, the following vulnerability has been resolved:

net: phy: sfp: free mii_bus in sfp_i2c_mdiobus_destroy

sfp_i2c_mdiobus_create() allocates the I2C MDIO bus with mdio_i2c_alloc(), a plain (non-devm) allocation, and registers it. sfp_i2c_mdiobus_destroy() only unregisters the bus and clears sfp->i2c_mii without calling mdiobus_free(). As the only reference to the bus is then cleared, the struct mii_bus is leaked.

This is hit whenever a copper/RollBall SFP module that instantiated an MDIO bus is removed: sfp_sm_main() takes the global teardown path and calls sfp_i2c_mdiobus_destroy(). sfp_cleanup(), on driver unbind, frees sfp->i2c_mii directly, which is why the leak only triggered on module hot-removal and not on unbind.

Free the bus in sfp_i2c_mdiobus_destroy() to match the allocation done in sfp_i2c_mdiobus_create().

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxe85b1347ace677c3822c12d9332dfaaffe594da6 < 92dd9a522f01ef57f633a8c1953cf6d48ef2bcd5affected
LinuxLinuxe85b1347ace677c3822c12d9332dfaaffe594da6 < d2c37f26d1a37f8177be5f354537f8ee3ec31cc2affected
LinuxLinuxe85b1347ace677c3822c12d9332dfaaffe594da6 < 3183b6f5510c876a1c4b4a6bdc3d0ad8940fe742affected
LinuxLinuxe85b1347ace677c3822c12d9332dfaaffe594da6 < 86d379fcf1b79bdf4bc2ac891297f30f63d041d8affected
LinuxLinuxe85b1347ace677c3822c12d9332dfaaffe594da6 < 2381bf3f484e8e4fd89a225445872ec14e036ab5affected
LinuxLinuxe85b1347ace677c3822c12d9332dfaaffe594da6 < 8f31efff9206f9f0adb853cad6916086aac4d5efaffected
LinuxLinux6.1affected
LinuxLinux0 < 6.1unaffected
LinuxLinux6.1.178 <= 6.1.*unaffected
LinuxLinux6.6.145 <= 6.6.*unaffected
LinuxLinux6.12.97 <= 6.12.*unaffected
LinuxLinux6.18.40 <= 6.18.*unaffected
LinuxLinux7.1.5 <= 7.1.*unaffected
LinuxLinux7.2 <= *unaffected

Weaknesses

References