Buffer Overflow in Linux Kernel's mac80211_hwsim Module

CVE-2026-98887

What is CVE-2026-98887?

The mac80211_hwsim module within the Linux kernel is susceptible to a buffer overflow due to improper validation of HWSIM_ATTR_TX_INFO attributes. Specifically, the function hwsim_tx_info_frame_received_nl() allows for the unconditional reading of a set number of bytes from the payload. If a short or zero-length attribute is processed, it leads to reading beyond the allocated memory, which can potentially compromise the system's integrity. To address this issue, it is crucial to enforce an exact length check in the policy, thereby rejecting malformed attributes before they reach the handler phase.

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