From 4f0cc46b76ee57a16fec70b67100642da50323a5 Mon Sep 17 00:00:00 2001 From: "Matthew Wilcox (Oracle)" Date: Fri, 9 Oct 2020 13:49:51 +0100 Subject: [PATCH] io_uring: Fix use of XArray in __io_uring_files_cancel commit ce765372bc443573d1d339a2bf4995de385dea3a upstream. We have to drop the lock during each iteration, so there's no advantage to using the advanced API. Convert this to a standard xa_for_each() loop. Reported-by: syzbot+27c12725d8ff0bfe1a13@syzkaller.appspotmail.com Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 19 +++++-------------- 1 file changed, 5 insertions(+), 14 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index cdce7598b9815..9a428f0abdf63 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8415,28 +8415,19 @@ static void io_uring_attempt_task_drop(struct file *file, bool exiting) void __io_uring_files_cancel(struct files_struct *files) { struct io_uring_task *tctx = current->io_uring; - XA_STATE(xas, &tctx->xa, 0); + struct file *file; + unsigned long index; /* make sure overflow events are dropped */ tctx->in_idle = true; - do { - struct io_ring_ctx *ctx; - struct file *file; - - xas_lock(&xas); - file = xas_next_entry(&xas, ULONG_MAX); - xas_unlock(&xas); - - if (!file) - break; - - ctx = file->private_data; + xa_for_each(&tctx->xa, index, file) { + struct io_ring_ctx *ctx = file->private_data; io_uring_cancel_task_requests(ctx, files); if (files) io_uring_del_task_file(file); - } while (1); + } } static inline bool io_uring_task_idle(struct io_uring_task *tctx)