Bug 2516586 (CVE-2026-72194)

Summary: CVE-2026-72194 kernel: fs/ntfs3: add depth limit to indx_find_buffer to prevent stack overflow
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's NTFS3 filesystem driver. A local attacker could craft a malicious NTFS image with circular index node references. When this filesystem is mounted and a specific file is deleted, it can trigger unbounded recursion in the `indx_find_buffer()` function, leading to a kernel stack overflow. This vulnerability results in a system panic, causing a Denial of Service (DoS).
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Description OSIDB Bzimport 2026-08-15 06:20:23 UTC 
In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: add depth limit to indx_find_buffer to prevent stack overflow

indx_find_buffer() recursively descends the B+ tree index with no depth
limit.  A crafted NTFS image with circular index node references causes
unbounded recursion, overflowing the kernel stack and panicking the
system.

This is reachable by mounting a malicious NTFS filesystem (e.g. from a
USB drive via desktop automount) and deleting a file whose index entry
triggers the rebalancing fallback path in indx_delete_entry().

Add a depth parameter and bail out with -EINVAL when it reaches the
fnd->nodes array bound, matching the constraint already enforced by
fnd_push() in indx_find().

The related function indx_find() was previously patched for a similar
infinite-loop issue (commit 1732053c8a6b), but indx_find_buffer() was
missed.
Comment 1 Keith Grant 2026-08-18 14:55:57 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081542-CVE-2026-72194-247a@gregkh/T