In the Linux kernel, the following vulnerability has been resolved: netfs: Fix missing alloc tagging of direct mempool allocations Commit… (CVE-2026-98920)

The Linux kernel netfs subsystem had a vulnerability where direct mempool allocations bypassed the alloc_hooks() wrapper, leading to missing current->alloc_tag settings when CONFIG_MEM_ALLOC_PROFILING_DEBUG=y. This caused warnings during allocation and free operations and omissions in /proc/allocinfo. The problem was fixed by introducing a new mempool_alloc_noreserve() helper that wraps direct ->alloc() calls with alloc_hooks(), preserving the failable allocation semantics while ensuring proper tagging.

The vulnerability caused allocation tagging warnings and missing allocation information in kernel profiling tools when reading files on CIFS mounts. It did not indicate a direct security compromise or memory corruption but affected kernel memory allocation profiling accuracy and could lead to noisy kernel warnings.

A fix has been applied in the Linux kernel source to wrap direct mempool allocations with allocation tagging hooks. Users should update to the fixed kernel version containing this patch. No additional mitigation is required as the issue is resolved by this official fix.