CVE-2026-80855

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_unlock() below the label so

that all error paths release the lock, and rename the label to

out_unlock as it now covers more than just the inode lock.