[PATCH] io_uring/uring_cmd: use cached cmd_op in io_uring_cmd_sock()

[Jens Axboe <axboe@kernel.dk>]

io_uring_cmd_sock() does a read of cmd->sqe->cmd_op, which may look
like it's the userspace shared SQE, but it's a copy at this point.
Use cmd->cmd_op rather than dip into the allocated SQE copy - it's
both simpler and faster and leaves less room for confusion.

Link: https://lore.kernel.org/r/20250121-uring-sockcmd-fix-v1-1-add742802a29@google.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

---

diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index fc94c465a985..3993c9339ac7 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -350,7 +350,7 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags)
 	if (!prot || !prot->ioctl)
 		return -EOPNOTSUPP;
 
-	switch (cmd->sqe->cmd_op) {
+	switch (cmd->cmd_op) {
 	case SOCKET_URING_OP_SIOCINQ:
 		ret = prot->ioctl(sk, SIOCINQ, &arg);
 		if (ret)
-- 
Jens Axboe