CyberRota Analysis
AI-GeneratedThe vulnerability affects the Linux kernel's CIFS implementation, specifically in the `cifs_remap_file_range()` function, where an underflow can occur if the length parameter is set to zero and the offset exceeds the inode size. This flaw can lead to corruption of the ByteCount in file requests, potentially resulting in data integrity issues. Organizations using Linux systems with CIFS should prioritize addressing this vulnerability to mitigate risks associated with file operations and ensure system stability.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: cifs: fix loff_t underflow in cifs_remap_file_range() when len == 0 With len == 0 (clone to EOF), the effective length is computed as: len = src_inode->i_size - off; If off > i_size, this is a negative loff_t, corrupting the ByteCount in the FSCTL_DUPLICATE_EXTENTS_TO_FILE request and inverting the range in filemap_write_and_wait_range(). The existing off >= i_size check fires only after the ioctl has already been sent. Snapshot i_size_read() once for both the bounds check and the length calculation, eliminating the TOCTOU and 32-bit torn-read risk. Reject off > src_size with -EINVAL. Treat off == src_size as a no-op, consistent with __generic_remap_file_range_prep().