In the Linux kernel, the following vulnerability has been resolved:
block: Fix WARNING in copyfrom_iter
Syzkaller reports a warning in copyfromiter because an ioviter is supposedly used in the wrong direction. The reason is that syzcaller managed to generate a request with a transfer direction of SGDXFERTOFROMDEV. 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.