fuse: fix invalidate lock leak on open O_TRUNC DAX failure
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() #