CVE-2026-31438

About vulnerability

In the Linux kernel, the following vulnerability has been resolved: netfs: Fix kernel BUG in netfs_limit_iter() for ITER_KVEC iterators When a process crashes and the kernel writes a core dump to a 9P filesystem, __kernel_write() creates an ITER_KVEC iterator. This iterator reaches netfs_limit_iter() via netfs_unbuffered_write(), which only handles ITER_FOLIOQ, ITER_BVEC and ITER_XARRAY iterator types, hitting the BUG() for any other type. Fix this by adding netfs_limit_kvec() following the same pattern as netfs_limit_bvec(), since both kvec and bvec are simple segment arrays with pointer and length fields. Dispatch it from netfs_limit_iter() when the iterator type is ITER_KVEC. A flaw was found in the Linux kernel’s netfs component. When a process crashes and the kernel attempts to write a core dump to a 9P filesystem, the netfs_limit_iter() function does not properly handle ITER_KVEC iterators. This oversight can lead to a kernel BUG, resulting in a system crash and a Denial of Service (DoS) for the affected system.

Live-patch status from KernelCare for each operating system.