io_uring: fix early fdput() of file

A previous commit shuffled some code around, and inadvertently used
struct file after fdput() had been called on it. As we can't touch
the file post fdput() dropping our reference, move the fdput() to
after that has been done.

Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/io-uring/YPnqM0fY3nM5RdRI@zeniv-ca.linux.org.uk/
Fixes: f2a48dd09b8e ("io_uring: refactor io_sq_offload_create()")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index fe3d948658ad33e30ab5063cfefd4b25a5d57e3d..f2fe4eca150bfedcd2fba612629127e6bad4a896 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7991,9 +7991,11 @@ static int io_sq_offload_create(struct io_ring_ctx *ctx,
                f = fdget(p->wq_fd);
                if (!f.file)
                        return -ENXIO;
-               fdput(f);
-               if (f.file->f_op != &io_uring_fops)
+               if (f.file->f_op != &io_uring_fops) {
+                       fdput(f);
                        return -EINVAL;
+               }
+               fdput(f);
        }
        if (ctx->flags & IORING_SETUP_SQPOLL) {
                struct task_struct *tsk;