crypto: algif_aead - snapshot IV for async AEAD requests

crypto: algif_aead - snapshot IV for async AEAD requests

AF_ALG AEAD AIO requests currently use the socket-wide IV buffer during
request processing.  For async requests, later socket activity can
update that shared state before the original request has fully
completed, which can lead to inconsistent IV handling.

Snapshot the IV into per-request storage when preparing the AEAD
request, so in-flight operations no longer depend on mutable socket
state.

Fixes: d887c52d6ae4 ("crypto: algif_aead - overhaul memory management")
Cc: stable@kernel.org
Reported-by: Yuan Tan <yuantan098@gmail.com>
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Reported-by: Xin Liu <bird@lzu.edu.cn>
Co-developed-by: Luxing Yin <tr0jan@lzu.edu.cn>
Signed-off-by: Luxing Yin <tr0jan@lzu.edu.cn>
Tested-by: Yucheng Lu <kanolyc@gmail.com>
Signed-off-by: Douya Le <ldy3087146292@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>