CVE-2026-80855

/// Technical description

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

fuse: fix invalidate lock leak on open O_TRUNC DAX failure

fuse_open() takes filemap_invalidate_lock() for a DAX truncate

(dax_truncate = true) and releases it before the out_inode_unlock

label. But when fuse_dax_break_layouts() fails, the goto

out_inode_unlock skips the unlock and leaks the rwsem, so any later

fault or truncate on the file stalls on the stale lock.

fuse_dax_break_layouts() can fail with -ERESTARTSYS when a signal

interrupts the wait for busy DAX pages to drain:

open("file", O_RDWR | O_TRUNC)

└─ fuse_open()

├─ filemap_invalidate_lock() # dax_truncate

└─ fuse_dax_break_layouts()

└─ dax_break_layout()

└─ wait_page_idle() # TASK_INTERRUPTIBLE

└─ fuse_wait_dax_page() # unlock, schedule, re-lock

└─ signal → -ERESTARTSYS

goto out_inode_unlock # <- lock leaked

Fix this by moving filemap_invalidate_unlo

/// 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