CVE-2026-72202
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk39th percentile - higher than 39% of all known CVEs
Summary
In the Linux kernel, the NTFS filesystem avoids heap allocation for free-cluster readahead state. get_nr_free_clusters() allocated a temporary file_ra_state before publishing the free cluster count, and if allocation failed, the worker returned without setting the flag or waking waiters, potentially causing indefinite blocking. Now the state is kept on the stack and passed by address, eliminating the allocation failure path.
Risk Assessment
Previous implementation could cause processes waiting for the free cluster count to hang, leading to system unresponsiveness.
Recommendation
Apply the kernel update containing this fix.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: ntfs: avoid heap allocation for free-cluster readahead state get_nr_free_clusters() allocates a temporary file_ra_state before it publishes the precomputed free cluster count, sets NVolFreeClusterKnown(), and wakes vol->free_waitq. If that allocation fails, the worker returns without setting the flag or waking waiters, so callers waiting for the free count can block indefinitely. The readahead state is only used synchronously while scanning the bitmap. Keep it on the stack and pass it by address to the readahead helper. This eliminates the early allocation failure path instead of adding a special case that publishes a conservative count and wakes the waitqueue. Zero-initialize the on-stack state because file_ra_state_init() only sets ra_pages and prev_pos. Apply the same treatment to __get_nr_free_mft_records(), which scans the MFT bitmap with the same short-lived readahead state.