Bug 2516375 (CVE-2026-72202) - CVE-2026-72202 kernel: ntfs: avoid heap allocation for free-cluster readahead state
Summary: CVE-2026-72202 kernel: ntfs: avoid heap allocation for free-cluster readahead...
Keywords:
Status: NEW
Alias: CVE-2026-72202
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:09 UTC by OSIDB Bzimport
Modified: 2026-08-18 15:13 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
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Last Closed:
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Description OSIDB Bzimport 2026-08-15 06:09:13 UTC
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.


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