Linux Kernel RXRPC IRQ-Disabled Vulnerability in MTU Assessment

A vulnerability in the Linux kernel's RXRPC implementation has been addressed. The issue arose because the 'rxrpc_assess_MTU_size()' function, which determines the Maximum Transmission Unit (MTU) size for a route, was called while interrupts were disabled. This created a conflict with the IP layer, which uses 'local_bh_enable()'—a function that can issue a warning if interrupts are enabled. The vulnerability was resolved by repositioning the MTU assessment call to a point in the process where interrupts are not disabled.

Impact

The vulnerability could lead to improper handling of network interrupts, potentially causing issues in packet processing or network communication.