CyberRota Analysis
AI-GeneratedA vulnerability in the Linux kernel affects the TCP implementation, where the assumption that the maximum segment size (MSS) will not be smaller than one can be violated, potentially leading to a divide-by-zero error. This flaw can arise from improperly configured route-derived MSS values, which may result in a denial-of-service condition. Organizations using Linux systems, particularly those relying on TCP for network communications, should prioritize addressing this vulnerability to maintain system stability and prevent service interruptions.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: tcp: clamp route advmss to TCP_MIN_MSS tcp_select_initial_window() assumes that callers never pass an MSS smaller than 1, but route-derived advmss values can violate that assumption. A too-small explicit RTAX_ADVMSS is one way to get there, but it is not the only one. The same divide-by-zero can also be reached through the "default advmss" path when RTAX_ADVMSS is left at 0 and the effective advmss is later driven down by route MTU and min_adv_mss. Introduce a tcp_dst_advmss() helper that clamps route advmss to TCP_MIN_MSS before TCP consumes it, and use it in the TCP paths that derive advmss from dst metrics. This keeps the effective MSS from dropping to zero before tcp_select_initial_window() rounds the receive window.