Bug 2516343 (CVE-2026-72188)

Summary: CVE-2026-72188 kernel: ntfs: sanitize MFT references returned from ntfs_lookup_inode_by_name()
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 NTFS filesystem driver. A remote attacker could craft a malicious NTFS image that, when processed, causes the ntfs_lookup_inode_by_name() function to return an unvalidated error-marked MFT (Master File Table) reference. This can lead to callers consuming a bogus error code, misinterpreting corrupted on-disk metadata, and potentially causing system instability or a denial of service.
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Description OSIDB Bzimport 2026-08-15 06:07:32 UTC 
In the Linux kernel, the following vulnerability has been resolved:

ntfs: sanitize MFT references returned from ntfs_lookup_inode_by_name()

ntfs_lookup_inode_by_name() returns MFT references read from directory
index entries on disk. These values are untrusted, but the function can
currently return an error-marked MFT reference to its callers without
validating it.

Callers later decode lookup failures with MREF_ERR(). A crafted NTFS image
can set the MREF error bit while leaving the low bits as an arbitrary
value, causing callers to consume a bogus pseudo-errno instead of treating
the lookup result as corrupted on-disk metadata.

Fix this at the source by normalizing every error-marked MFT reference
returned from ntfs_lookup_inode_by_name() to ERR_MREF(-EIO). Apply this to
all four directory lookup return paths so every caller gets a validated
result without needing additional checks or an API change.

This keeps the sanitization in the common lookup helper, which is cleaner
than duplicating validation in each caller.
Comment 1 gkamathe 2026-08-18 07:04:34 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081541-CVE-2026-72188-0c40@gregkh/T