Bug 2492361 (CVE-2026-53023)

Summary: CVE-2026-53023 kernel: fs/ntfs3: terminate the cached volume label after UTF-8 conversion
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
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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 file system driver. The `ntfs_fill_super()` function, responsible for loading the volume label, did not properly null-terminate the converted UTF-8 label. This oversight could allow the `ntfs3_label_show()` function to read beyond the allocated buffer when displaying the volume label, potentially leading to information disclosure.
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Description OSIDB Bzimport 2026-06-24 18:07:52 UTC 
In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: terminate the cached volume label after UTF-8 conversion

ntfs_fill_super() loads the on-disk volume label with utf16s_to_utf8s()
and stores the result in sbi->volume.label. The converted label is later
exposed through ntfs3_label_show() using %s, but utf16s_to_utf8s() only
returns the number of bytes written and does not add a trailing NUL.

If the converted label fills the entire fixed buffer,
ntfs3_label_show() can read past the end of sbi->volume.label while
looking for a terminator.

Terminate the cached label explicitly after a successful conversion and
clamp the exact-full case to the last byte of the buffer.
Comment 1 Keith Grant 2026-06-26 19:33:06 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062452-CVE-2026-53023-5a0a@gregkh/T