io_uring: don't guard IORING_OFF_PBUF_RING with SETUP_NO_MMAP

commit 6f007b1406637d3d73d42e41d7e8d9b245185e69 upstream.

This flag only applies to the SQ and CQ rings, it's perfectly valid
to use a mmap approach for the provided ring buffers. Move the
check into where it belongs.

Cc: stable@vger.kernel.org
Fixes: 03d89a2de25b ("io_uring: support for user allocated memory for rings/sqes")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index efd5331..5570c15 100644 (file)
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3436,16 +3436,18 @@ static void *io_uring_validate_mmap_request(struct file *file,
        struct page *page;
        void *ptr;
 
-       /* Don't allow mmap if the ring was setup without it */
-       if (ctx->flags & IORING_SETUP_NO_MMAP)
-               return ERR_PTR(-EINVAL);
-
        switch (offset & IORING_OFF_MMAP_MASK) {
        case IORING_OFF_SQ_RING:
        case IORING_OFF_CQ_RING:
+               /* Don't allow mmap if the ring was setup without it */
+               if (ctx->flags & IORING_SETUP_NO_MMAP)
+                       return ERR_PTR(-EINVAL);
                ptr = ctx->rings;
                break;
        case IORING_OFF_SQES:
+               /* Don't allow mmap if the ring was setup without it */
+               if (ctx->flags & IORING_SETUP_NO_MMAP)
+                       return ERR_PTR(-EINVAL);
                ptr = ctx->sq_sqes;
                break;
        case IORING_OFF_PBUF_RING: {