CVE-2026-53023: fs/ntfs3: terminate the cached volume label after UTF-8 conversion

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-06-24 · updated 2026-07-15

Description

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.

Affected products

Linux kernel: from 5.15 before 5.15.209; from 5.16 before 6.1.175; from 6.2 before 6.6.141; from 6.7 before 6.12.91; from 6.13 before 6.18.33; from 6.19 before 7.0.10 — fixed in 5.15.209, 6.1.175, 6.12.91, 6.18.33, 6.6.141, 7.0.10

How to fix

Upgrade to a fixed version: Linux kernel 5.15.209, 6.1.175, 6.12.91, 6.18.33. Check the vendor advisory for mitigations.

References

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