CVE-2024-26844

In the Linux kernel, the following vulnerability has been resolved: block:
Fix WARNING in _copy_from_iter Syzkaller reports a warning in
_copy_from_iter because an iov_iter is supposedly used in the wrong
direction. The reason is that syzcaller managed to generate a request with
a transfer direction of SG_DXFER_TO_FROM_DEV. This instructs the kernel to
copy user buffers into the kernel, read into the copied buffers and then
copy the data back to user space. Thus the iovec is used in both
directions. Detect this situation in the block layer and construct a new
iterator with the correct direction for the copy-in.