Executive brief
A vulnerability in the Linux kernel's txgbe network driver could cause a system warning or instability when the driver module is removed. This affects systems using specific copper network interface cards with external physical layer (PHY) components. While primarily a stability issue, it could impact system availability during maintenance or driver updates.
Technical details
A vulnerability in the Linux kernel txgbe network driver arises from a missing RTNL (Routing Netlink) lock during the module removal process. Specifically, for copper NICs with an external PHY, the driver calls phylink_disconnect_phy() without holding the required rtnl_lock, triggering an assertion failure in the phylink core. An attacker with high privileges (capable of unloading kernel modules) could trigger this condition, leading to kernel warnings and potential instability. The fix involves wrapping the phylink_disconnect_phy() call with rtnl_lock() and rtnl_unlock() in the txgbe_remove_phy function.
Affected products
- Linux Linux kernel 7.0.0-rc4+
Timeline
- 2026-05-06: other: Patch authored
- 2026-06-08: disclosed: CVE published
References
- https://git.kernel.org/stable/c/0305e7118451c7c363c18f8113b0d8e0077ffa4c
- https://git.kernel.org/stable/c/3e223a7fd41ce6fffdb10577df9350385262bf33
- https://git.kernel.org/stable/c/6c5ec52c68a6a442c8a159615ae092512562318a
- https://git.kernel.org/stable/c/d29cafc7e4ee9e28a150ba17e9a565ec5d881fbc
- https://git.kernel.org/stable/c/e159f05e12cc1111a3103b99375ddf0dfd0e7d63