From d785a773bed966a75ca1f11d108ae1897189975b Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Sat, 9 Jul 2022 07:02:10 -0600 Subject: io_uring: check that we have a file table when allocating update slots If IORING_FILE_INDEX_ALLOC is set asking for an allocated slot, the helper doesn't check if we actually have a file table or not. The non alloc path does do that correctly, and returns -ENXIO if we haven't set one up. Do the same for the allocated path, avoiding a NULL pointer dereference when trying to find a free bit. Fixes: a7c41b4687f5 ("io_uring: let IORING_OP_FILES_UPDATE support choosing fixed file slots") Signed-off-by: Jens Axboe --- fs/io_uring.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index cddc0e8490af..a01ea49f3017 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7973,6 +7973,9 @@ static int io_files_update_with_index_alloc(struct io_kiocb *req, struct file *file; int ret, fd; + if (!req->ctx->file_data) + return -ENXIO; + for (done = 0; done < req->rsrc_update.nr_args; done++) { if (copy_from_user(&fd, &fds[done], sizeof(fd))) { ret = -EFAULT; -- cgit