From 47abea041f897d64dbd5777f0cf7745148f85d75 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 23 Aug 2022 07:26:08 -0600 Subject: io_uring: fix off-by-one in sync cancelation file check The passed in index should be validated against the number of registered files we have, it needs to be smaller than the index value to avoid going one beyond the end. Fixes: 78a861b94959 ("io_uring: add sync cancelation API through io_uring_register()") Reported-by: Luo Likang Signed-off-by: Jens Axboe --- io_uring/cancel.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'io_uring/cancel.c') diff --git a/io_uring/cancel.c b/io_uring/cancel.c index e4e1dc0325f0..5fc5d3e80fcb 100644 --- a/io_uring/cancel.c +++ b/io_uring/cancel.c @@ -218,7 +218,7 @@ static int __io_sync_cancel(struct io_uring_task *tctx, (cd->flags & IORING_ASYNC_CANCEL_FD_FIXED)) { unsigned long file_ptr; - if (unlikely(fd > ctx->nr_user_files)) + if (unlikely(fd >= ctx->nr_user_files)) return -EBADF; fd = array_index_nospec(fd, ctx->nr_user_files); file_ptr = io_fixed_file_slot(&ctx->file_table, fd)->file_ptr; -- cgit v1.2.3