[PATCH] io_uring/uring_cmd: fix buffer index retrieval

[Ming Lei <ming.lei@redhat.com>]

Add back buffer index retrieval for IORING_URING_CMD_FIXED.

Reported-by: Guangwu Zhang <guazhang@redhat.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Fixes: b54a14041ee6 ("io_uring/rsrc: add io_rsrc_node_lookup() helper")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 io_uring/uring_cmd.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index e7723759cb23..1abb5c9f803f 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -220,8 +220,9 @@ int io_uring_cmd_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 	if (ioucmd->flags & IORING_URING_CMD_FIXED) {
 		struct io_ring_ctx *ctx = req->ctx;
 		struct io_rsrc_node *node;
+		u16 index = READ_ONCE(sqe->buf_index);
 
-		node = io_rsrc_node_lookup(&ctx->buf_table, req->buf_index);
+		node = io_rsrc_node_lookup(&ctx->buf_table, index);
 		if (unlikely(!node))
 			return -EFAULT;
 		/*
-- 
2.46.0