CVE-2026-93140

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

udf: Mark LVID buffer as uptodate before marking it dirty

When an I/O error occurs while writing the Logical Volume Integrity

Descriptor (LVID) buffer to the block device, the block layer's completion

handler (`end_buffer_write_sync()`) clears the `BH_Uptodate` flag on the

buffer. However, the buffer still contains valid LVID data in memory. If

the filesystem is subsequently remounted read-write or synced,

`udf_open_lvid()` or `udf_sync_fs()` will modify the LVID buffer and call

`mark_buffer_dirty()`. This triggers a spurious

`WARN_ON_ONCE(!buffer_uptodate(bh))` warning in `mark_buffer_dirty()`

because the buffer is not marked uptodate, even though its in-memory

contents are valid and are about to be overwritten.

To prevent this spurious warning, unconditionally set the `BH_Uptodate`

flag before calling `mark_buffer_dirty()` in `udf_open_lvid()` and

`udf_sync_fs()`. This acknowledges that the in-memory buffer is val

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References