Use-after-free Vulnerability in Linux Kernel Affects FUSE

CVE-2026-80857

What is CVE-2026-80857?

A use-after-free vulnerability exists in the Linux kernel within the FUSE component. The issue arises when the abort_on_kill path in request_wait_answer calls fuse_abort_conn and returns prematurely without waiting for the FR_FINISHED state. This can result in a race condition where the fuse_dev_do_write function is processing the same request, potentially leading to memory corruption as the requester may free req->args while still being accessed by the concurrent thread. The vulnerability has been addressed by modifying the flow to ensure proper waiting for FR_FINISHED, preventing the free operation from occurring while the data is still in use.

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